/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_RFM22B Radio Functions
* @brief PIOS interface for for the RFM22B radio
* @{
*
* @file pios_rfm22b.c
* @author The LibrePilot Project, http://www.librepilot.org Copyright (C) 2016.
* The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief Implements a driver the the RFM22B driver
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// *****************************************************************
// RFM22B hardware layer
//
// This module uses the RFM22B's internal packet handling hardware to
// encapsulate our own packet data.
//
// The RFM22B internal hardware packet handler configuration is as follows:
//
// 6-byte (32-bit) preamble .. alternating 0's & 1's
// 4-byte (32-bit) sync
// 1-byte packet length (number of data bytes to follow)
// 0 to 251 user data bytes
// 4 byte ECC
//
// OR in PPM only mode:
//
// 6-byte (32-bit) preamble .. alternating 0's & 1's
// 4-byte (32-bit) sync
// 1-byte packet length (number of data bytes to follow)
// 1 byte PPM values LSB (bit 0)
// 8 bytes PPM values MSBs (bit 8:1)
// 1 byte CRC
//
// *****************************************************************
#include "pios.h"
#ifdef PIOS_INCLUDE_RFM22B
#include <pios_spi_priv.h>
#include <pios_rfm22b_regs.h>
#include <pios_rfm22b_priv.h>
#include <pios_ppm_out.h>
#include <ecc.h>
#include <sha1.h>
/* Local Defines */
#define STACK_SIZE_BYTES 200
#define TASK_PRIORITY (tskIDLE_PRIORITY + 4) // flight control relevant device driver (ppm link)
#define ISR_TIMEOUT 1 // ms
#define EVENT_QUEUE_SIZE 5
#define RFM22B_DEFAULT_RX_DATARATE RFM22_datarate_9600
#define RFM22B_DEFAULT_TX_POWER RFM22_tx_pwr_txpow_0
#define RFM22B_NOMINAL_CARRIER_FREQUENCY_433 430000000
#define RFM22B_NOMINAL_CARRIER_FREQUENCY_868 860000000
#define RFM22B_NOMINAL_CARRIER_FREQUENCY_915 900000000
#define RFM22B_LINK_QUALITY_THRESHOLD 20
#define RFM22B_DEFAULT_MIN_CHANNEL 0
#define RFM22B_DEFAULT_MAX_CHANNEL 250
#define RFM22B_PPM_ONLY_DATARATE RFM22_datarate_9600
// PPM encoding limits
#define RFM22B_PPM_MIN 1
#define RFM22B_PPM_MAX 511
#define RFM22B_PPM_INVALID 0
#define RFM22B_PPM_SCALE 2
#define RFM22B_PPM_MIN_US 990
#define RFM22B_PPM_MAX_US (RFM22B_PPM_MIN_US + (RFM22B_PPM_MAX - RFM22B_PPM_MIN) * RFM22B_PPM_SCALE)
// The maximum amount of time without activity before initiating a reset.
#define PIOS_RFM22B_SUPERVISOR_TIMEOUT 150 // ms
// this is too adjust the RF module so that it is on frequency
#define OSC_LOAD_CAP 0x7F // cap = 12.5pf .. default
#define TX_PREAMBLE_NIBBLES 12 // 7 to 511 (number of nibbles)
#define RX_PREAMBLE_NIBBLES 6 // 5 to 31 (number of nibbles)
#define SYNC_BYTES 4
#define HEADER_BYTES 4
#define LENGTH_BYTES 1
// the size of the rf modules internal FIFO buffers
#define FIFO_SIZE 64
#define TX_FIFO_HI_WATERMARK 62 // 0-63
#define TX_FIFO_LO_WATERMARK 32 // 0-63
#define RX_FIFO_HI_WATERMARK 32 // 0-63
// preamble byte (preceeds SYNC_BYTE's)
#define PREAMBLE_BYTE 0x55
// RF sync bytes (32-bit in all)
#define SYNC_BYTE_1 0x2D
#define SYNC_BYTE_2 0xD4
#define SYNC_BYTE_3 0x4B
#define SYNC_BYTE_4 0x59
#ifndef RX_LED_ON
#define RX_LED_ON
#define RX_LED_OFF
#define TX_LED_ON
#define TX_LED_OFF
#define LINK_LED_ON
#define LINK_LED_OFF
#define USB_LED_ON
#define USB_LED_OFF
#endif
#define CONNECTED_TIMEOUT (250 / portTICK_RATE_MS) /* ms */
#define MAX_CHANNELS 32
/* Local type definitions */
struct pios_rfm22b_transition {
enum pios_radio_event (*entry_fn)(struct pios_rfm22b_dev *rfm22b_dev);
enum pios_radio_state next_state[RADIO_EVENT_NUM_EVENTS];
};
// Must ensure these prefilled arrays match the define sizes
static const uint8_t FULL_PREAMBLE[FIFO_SIZE] = {
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE,
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE
}; // 64 bytes
static const uint8_t HEADER[(TX_PREAMBLE_NIBBLES + 1) / 2 + 2] = {
PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, PREAMBLE_BYTE, SYNC_BYTE_1, SYNC_BYTE_2
};
static const uint8_t OUT_FF[64] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
};
/* Local function forwared declarations */
static void pios_rfm22_task(void *parameters);
static bool pios_rfm22_readStatus(struct pios_rfm22b_dev *rfm22b_dev);
static void pios_rfm22_setDatarate(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_rxFailure(struct pios_rfm22b_dev *rfm22b_dev);
static void pios_rfm22_inject_event(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event, bool inISR);
static enum pios_radio_event rfm22_init(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event radio_setRxMode(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event radio_rxData(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event radio_receivePacket(struct pios_rfm22b_dev *rfm22b_dev, uint8_t *p, uint16_t rx_len);
static enum pios_radio_event radio_txStart(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event radio_txData(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event rfm22_txFailure(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event rfm22_process_state_transition(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event);
static void rfm22_process_event(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event);
static enum pios_radio_event rfm22_timeout(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event rfm22_error(struct pios_rfm22b_dev *rfm22b_dev);
static enum pios_radio_event rfm22_fatal_error(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22b_add_rx_status(struct pios_rfm22b_dev *rfm22b_dev, enum pios_rfm22b_rx_packet_status status);
static void rfm22_setNominalCarrierFrequency(struct pios_rfm22b_dev *rfm22b_dev, uint8_t init_chan, uint32_t frequency_hz);
static bool rfm22_setFreqHopChannel(struct pios_rfm22b_dev *rfm22b_dev, uint8_t channel);
static void rfm22_generateDeviceID(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_updateStats(struct pios_rfm22b_dev *rfm22b_dev);
static bool rfm22_checkTimeOut(struct pios_rfm22b_dev *rfm22b_dev);
static bool rfm22_isConnected(struct pios_rfm22b_dev *rfm22b_dev);
static bool rfm22_isCoordinator(struct pios_rfm22b_dev *rfm22b_dev);
static uint32_t rfm22_destinationID(struct pios_rfm22b_dev *rfm22b_dev);
static bool rfm22_timeToSend(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_synchronizeClock(struct pios_rfm22b_dev *rfm22b_dev);
static uint32_t rfm22_coordinatorTime(struct pios_rfm22b_dev *rfm22b_dev);
static uint8_t rfm22_calcChannel(struct pios_rfm22b_dev *rfm22b_dev, uint8_t index);
static uint8_t rfm22_calcChannelFromClock(struct pios_rfm22b_dev *rfm22b_dev);
static bool rfm22_changeChannel(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_clearLEDs();
// Utility functions.
static uint32_t pios_rfm22_time_ms();
static uint32_t pios_rfm22_time_difference_ms(uint32_t start_time, uint32_t end_time);
static struct pios_rfm22b_dev *pios_rfm22_alloc(void);
static void rfm22_hmac_sha1(const uint8_t *data, size_t len, uint8_t key[SHA1_DIGEST_LENGTH],
uint8_t digest[SHA1_DIGEST_LENGTH]);
static bool rfm22_gen_channels(uint32_t coordid, enum rfm22b_datarate datarate, uint8_t min,
uint8_t max, uint8_t channels[MAX_CHANNELS], uint8_t *clen);
// SPI read/write functions
static void rfm22_assertCs(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_deassertCs(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_claimBus(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_releaseBus(struct pios_rfm22b_dev *rfm22b_dev);
static void rfm22_write_claim(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr, uint8_t data);
static void rfm22_write(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr, uint8_t data);
static uint8_t rfm22_read(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr);
/* The state transition table */
static const struct pios_rfm22b_transition rfm22b_transitions[RADIO_STATE_NUM_STATES] = {
// Initialization thread
[RADIO_STATE_UNINITIALIZED] = {
.entry_fn = 0,
.next_state = {
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
},
},
[RADIO_STATE_INITIALIZING] = {
.entry_fn = rfm22_init,
.next_state = {
[RADIO_EVENT_INITIALIZED] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_RX_MODE] = {
.entry_fn = radio_setRxMode,
.next_state = {
[RADIO_EVENT_INT_RECEIVED] = RADIO_STATE_RX_DATA,
[RADIO_EVENT_TX_START] = RADIO_STATE_TX_START,
[RADIO_EVENT_RX_MODE] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_TIMEOUT] = RADIO_STATE_TIMEOUT,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_RX_DATA] = {
.entry_fn = radio_rxData,
.next_state = {
[RADIO_EVENT_INT_RECEIVED] = RADIO_STATE_RX_DATA,
[RADIO_EVENT_TX_START] = RADIO_STATE_TX_START,
[RADIO_EVENT_RX_COMPLETE] = RADIO_STATE_TX_START,
[RADIO_EVENT_RX_MODE] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_TIMEOUT] = RADIO_STATE_TIMEOUT,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_TX_START] = {
.entry_fn = radio_txStart,
.next_state = {
[RADIO_EVENT_INT_RECEIVED] = RADIO_STATE_TX_DATA,
[RADIO_EVENT_RX_MODE] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_TIMEOUT] = RADIO_STATE_TIMEOUT,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_TX_DATA] = {
.entry_fn = radio_txData,
.next_state = {
[RADIO_EVENT_INT_RECEIVED] = RADIO_STATE_TX_DATA,
[RADIO_EVENT_RX_MODE] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_TIMEOUT] = RADIO_STATE_TIMEOUT,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_TX_FAILURE] = {
.entry_fn = rfm22_txFailure,
.next_state = {
[RADIO_EVENT_TX_START] = RADIO_STATE_TX_START,
[RADIO_EVENT_TIMEOUT] = RADIO_STATE_TIMEOUT,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_TIMEOUT] = {
.entry_fn = rfm22_timeout,
.next_state = {
[RADIO_EVENT_TX_START] = RADIO_STATE_TX_START,
[RADIO_EVENT_RX_MODE] = RADIO_STATE_RX_MODE,
[RADIO_EVENT_ERROR] = RADIO_STATE_ERROR,
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_ERROR] = {
.entry_fn = rfm22_error,
.next_state = {
[RADIO_EVENT_INITIALIZE] = RADIO_STATE_INITIALIZING,
[RADIO_EVENT_FATAL_ERROR] = RADIO_STATE_FATAL_ERROR,
},
},
[RADIO_STATE_FATAL_ERROR] = {
.entry_fn = rfm22_fatal_error,
.next_state = {},
},
};
// xtal 10 ppm, 434MHz
static const uint32_t data_rate[] = {
9600, // 96 kbps, 433 HMz, 30 khz freq dev
19200, // 19.2 kbps, 433 MHz, 45 khz freq dev
32000, // 32 kbps, 433 MHz, 45 khz freq dev
57600, // 57.6 kbps, 433 MHz, 45 khz freq dev
64000, // 64 kbps, 433 MHz, 45 khz freq dev
100000, // 100 kbps, 433 MHz, 60 khz freq dev
128000, // 128 kbps, 433 MHz, 90 khz freq dev
192000, // 192 kbps, 433 MHz, 128 khz freq dev
256000, // 256 kbps, 433 MHz, 150 khz freq dev
};
static const uint8_t channel_spacing[] = {
1, /* 9.6kbps */
2, /* 19.2kps */
2, /* 32kps */
2, /* 57.6kps */
2, /* 64kps */
3, /* 100kps */
4, /* 128kps */
4, /* 192kps */
4 /* 256kps */
};
static const uint8_t reg_1C[] = { 0x01, 0x05, 0x06, 0x95, 0x95, 0x81, 0x88, 0x8B, 0x8D }; // rfm22_if_filter_bandwidth
static const uint8_t reg_1D[] = { 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40 }; // rfm22_afc_loop_gearshift_override
static const uint8_t reg_1E[] = { 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x02 }; // rfm22_afc_timing_control
static const uint8_t reg_1F[] = { 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03 }; // rfm22_clk_recovery_gearshift_override
static const uint8_t reg_20[] = { 0xA1, 0xD0, 0x7D, 0x68, 0x5E, 0x78, 0x5E, 0x3F, 0x2F }; // rfm22_clk_recovery_oversampling_ratio
static const uint8_t reg_21[] = { 0x20, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02 }; // rfm22_clk_recovery_offset2
static const uint8_t reg_22[] = { 0x4E, 0x9D, 0x06, 0x3A, 0x5D, 0x11, 0x5D, 0x0C, 0xBB }; // rfm22_clk_recovery_offset1
static const uint8_t reg_23[] = { 0xA5, 0x49, 0x25, 0x93, 0x86, 0x11, 0x86, 0x4A, 0x0D }; // rfm22_clk_recovery_offset0
static const uint8_t reg_24[] = { 0x00, 0x00, 0x01, 0x03, 0x03, 0x03, 0x03, 0x06, 0x07 }; // rfm22_clk_recovery_timing_loop_gain1
static const uint8_t reg_25[] = { 0x34, 0x88, 0x77, 0x29, 0xE2, 0x90, 0xE2, 0x1A, 0xFF }; // rfm22_clk_recovery_timing_loop_gain0
static const uint8_t reg_2A[] = { 0x1E, 0x24, 0x28, 0x3C, 0x3C, 0x50, 0x50, 0x50, 0x50 }; // rfm22_afc_limiter .. AFC_pull_in_range = �AFCLimiter[7:0] x (hbsel+1) x 625 Hz
static const uint8_t reg_58[] = { 0x80, 0x80, 0x80, 0x80, 0x80, 0xC0, 0xC0, 0xC0, 0xED }; // rfm22_cpcuu
static const uint8_t reg_69[] = { 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60, 0x60 }; // rfm22_agc_override1
static const uint8_t reg_6E[] = { 0x4E, 0x9D, 0x08, 0x0E, 0x10, 0x19, 0x20, 0x31, 0x41 }; // rfm22_tx_data_rate1
static const uint8_t reg_6F[] = { 0xA5, 0x49, 0x31, 0xBF, 0x62, 0x9A, 0xC5, 0x27, 0x89 }; // rfm22_tx_data_rate0
static const uint8_t reg_70[] = { 0x2C, 0x2C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C }; // rfm22_modulation_mode_control1
static const uint8_t reg_71[] = { 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23 }; // rfm22_modulation_mode_control2
static const uint8_t reg_72[] = { 0x30, 0x48, 0x48, 0x48, 0x48, 0x60, 0x90, 0xCD, 0x0F }; // rfm22_frequency_deviation
static const uint8_t packet_time[] = { 80, 40, 25, 15, 13, 10, 8, 6, 5 };
static const uint8_t packet_time_ppm[] = { 26, 25, 25, 15, 13, 10, 8, 6, 5 };
static const uint8_t num_channels[] = { 32, 32, 32, 32, 32, 32, 32, 32, 32 };
static struct pios_rfm22b_dev *g_rfm22b_dev = NULL;
/*****************************************************************************
* External Interface Functions
*****************************************************************************/
/**
* Initialise an RFM22B device
*
* @param[out] rfm22b_id A pointer to store the device ID in.
* @param[in] spi_id The SPI bus index.
* @param[in] slave_num The SPI bus slave number.
* @param[in] cfg The device configuration.
*/
int32_t PIOS_RFM22B_Init(uint32_t *rfm22b_id, uint32_t spi_id, uint32_t slave_num, const struct pios_rfm22b_cfg *cfg, OPLinkSettingsRFBandOptions band)
{
PIOS_DEBUG_Assert(rfm22b_id);
PIOS_DEBUG_Assert(cfg);
// Allocate the device structure.
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)pios_rfm22_alloc();
if (!rfm22b_dev) {
return -1;
}
*rfm22b_id = (uint32_t)rfm22b_dev;
g_rfm22b_dev = rfm22b_dev;
// Store the SPI handle
rfm22b_dev->slave_num = slave_num;
rfm22b_dev->spi_id = spi_id;
// Initialize our configuration parameters
rfm22b_dev->datarate = RFM22B_DEFAULT_RX_DATARATE;
rfm22b_dev->tx_power = RFM22B_DEFAULT_TX_POWER;
// Set the frequency band
switch (band) {
case OPLINKSETTINGS_RFBAND_915MHZ:
rfm22b_dev->base_freq = RFM22B_NOMINAL_CARRIER_FREQUENCY_915;
break;
case OPLINKSETTINGS_RFBAND_868MHZ:
rfm22b_dev->base_freq = RFM22B_NOMINAL_CARRIER_FREQUENCY_868;
break;
case OPLINKSETTINGS_RFBAND_433MHZ:
default:
rfm22b_dev->base_freq = RFM22B_NOMINAL_CARRIER_FREQUENCY_433;
break;
}
// Initialize the channels.
PIOS_RFM22B_SetChannelConfig(*rfm22b_id, RFM22B_DEFAULT_RX_DATARATE, RFM22B_DEFAULT_MIN_CHANNEL,
RFM22B_DEFAULT_MAX_CHANNEL, false, true, false);
// Create the event queue
rfm22b_dev->eventQueue = xQueueCreate(EVENT_QUEUE_SIZE, sizeof(enum pios_radio_event));
// Bind the configuration to the device instance
rfm22b_dev->cfg = *cfg;
// Create a semaphore to know if an ISR needs responding to
vSemaphoreCreateBinary(rfm22b_dev->isrPending);
// Create default (hopefully) unique 32 bit id from the processor serial number.
rfm22_generateDeviceID(rfm22b_dev);
// Initialize the external interrupt.
PIOS_EXTI_Init(cfg->exti_cfg);
// Register the watchdog timer for the radio driver task
#if defined(PIOS_INCLUDE_WDG) && defined(PIOS_WDG_RFM22B)
PIOS_WDG_RegisterFlag(PIOS_WDG_RFM22B);
#endif /* PIOS_WDG_RFM22B */
// Initialize the ECC library.
initialize_ecc();
// Set the state to initializing.
rfm22b_dev->state = RADIO_STATE_UNINITIALIZED;
// Initialize the radio device.
pios_rfm22_inject_event(rfm22b_dev, RADIO_EVENT_INITIALIZE, false);
// Start the driver task. This task controls the radio state machine and removed all of the IO from the IRQ handler.
xTaskCreate(pios_rfm22_task, "PIOS_RFM22B_Task", STACK_SIZE_BYTES, (void *)rfm22b_dev, TASK_PRIORITY, &(rfm22b_dev->taskHandle));
return 0;
}
/**
* Re-initialize the modem after a configuration change.
*
* @param[in] rbm22b_id The RFM22B device ID.
*/
void PIOS_RFM22B_Reinit(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
pios_rfm22_inject_event(rfm22b_dev, RADIO_EVENT_INITIALIZE, false);
}
}
/**
* The RFM22B external interrupt routine.
*/
bool PIOS_RFM22_EXT_Int(void)
{
if (!PIOS_RFM22B_Validate(g_rfm22b_dev)) {
return false;
}
// Inject an interrupt event into the state machine.
pios_rfm22_inject_event(g_rfm22b_dev, RADIO_EVENT_INT_RECEIVED, true);
return false;
}
/**
* Set the device ID for the RFM22B device.
*
* @param[in] rfm22b_id The RFM22B device index.
*
*/
void PIOS_RFM22B_SetDeviceID(uint32_t rfm22b_id, uint32_t custom_device_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (custom_device_id > 0) {
rfm22b_dev->deviceID = custom_device_id;
} else {
rfm22_generateDeviceID(rfm22b_dev);
}
DEBUG_PRINTF(2, "RF device ID: %x\n\r", rfm22b_dev->deviceID);
}
/**
* Returns the unique device ID for the RFM22B device.
*
* @param[in] rfm22b_id The RFM22B device index.
* @return The unique device ID
*/
uint32_t PIOS_RFM22B_DeviceID(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
return rfm22b_dev->deviceID;
}
return 0;
}
/**
* Are we connected to the remote modem?
*
* @param[in] rfm22b_dev The device structure
*/
static bool rfm22_isConnected(struct pios_rfm22b_dev *rfm22b_dev)
{
return (rfm22b_dev->stats.link_state == OPLINKSTATUS_LINKSTATE_CONNECTED) || (rfm22b_dev->stats.link_state == OPLINKSTATUS_LINKSTATE_CONNECTING);
}
/**
* Returns true if the modem is not actively sending or receiving a packet.
*
* @param[in] rfm22b_id The RFM22B device index.
* @return True if the modem is not actively sending or receiving a packet.
*/
bool PIOS_RFM22B_InRxWait(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
return (rfm22b_dev->rfm22b_state == RFM22B_STATE_RX_WAIT) || (rfm22b_dev->rfm22b_state == RFM22B_STATE_TRANSITION);
}
return false;
}
/**
* Sets the radio device transmit power.
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[in] tx_pwr The transmit power.
*/
void PIOS_RFM22B_SetTxPower(uint32_t rfm22b_id, enum rfm22b_tx_power tx_pwr)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
rfm22b_dev->tx_power = tx_pwr;
}
/**
* Sets the range and number of channels to use for the radio.
* The channels are 0 to 250 divided across the 430-440 MHz range.
* The number of channels configured will be spread across the selected channel range.
* The channel spacing is 10MHz / 250 = 40kHz
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[in] datarate The desired datarate.
* @param[in] min_chan The minimum channel.
* @param[in] max_chan The maximum channel.
* @param[in] coordinator Is this modem an coordinator.
* @param[in] data_mode Should this modem send/receive data packets?
* @param[in] ppm_mode Should this modem send/receive ppm packets?
*/
void PIOS_RFM22B_SetChannelConfig(uint32_t rfm22b_id, enum rfm22b_datarate datarate, uint8_t min_chan, uint8_t max_chan, bool coordinator, bool data_mode, bool ppm_mode)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
bool ppm_only = ppm_mode && !data_mode;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
rfm22b_dev->coordinator = coordinator;
rfm22b_dev->ppm_send_mode = ppm_mode && coordinator;
rfm22b_dev->ppm_recv_mode = ppm_mode && !coordinator;
if (ppm_mode && (datarate <= RFM22B_PPM_ONLY_DATARATE)) {
ppm_only = true;
}
rfm22b_dev->ppm_only_mode = ppm_only;
if (ppm_only) {
rfm22b_dev->one_way_link = true;
datarate = RFM22B_PPM_ONLY_DATARATE;
rfm22b_dev->datarate = RFM22B_PPM_ONLY_DATARATE;
} else {
rfm22b_dev->one_way_link = false;
rfm22b_dev->datarate = datarate;
}
rfm22b_dev->packet_time = (ppm_mode ? packet_time_ppm[datarate] : packet_time[datarate]);
uint8_t num_found = 0;
rfm22_gen_channels(rfm22_destinationID(rfm22b_dev), datarate, min_chan, max_chan,
rfm22b_dev->channels, &num_found);
rfm22b_dev->num_channels = num_found;
// Calculate the maximum packet length from the datarate.
float bytes_per_period = (float)data_rate[datarate] * (float)(rfm22b_dev->packet_time - 2) / 9000;
rfm22b_dev->max_packet_len = bytes_per_period - TX_PREAMBLE_NIBBLES / 2 - SYNC_BYTES - HEADER_BYTES - LENGTH_BYTES;
if (rfm22b_dev->max_packet_len > RFM22B_MAX_PACKET_LEN) {
rfm22b_dev->max_packet_len = RFM22B_MAX_PACKET_LEN;
}
}
/**
* Set a XtalCap
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[in] XtalCap Value.
*/
void PIOS_RFM22B_SetXtalCap(uint32_t rfm22b_id, uint8_t xtal_cap)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
rfm22b_dev->cfg.RFXtalCap = xtal_cap;
}
}
/**
* Set a modem to be a coordinator or not.
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[in] coordinator If true, this modem will be configured as a coordinator.
*/
extern void PIOS_RFM22B_SetCoordinator(uint32_t rfm22b_id, bool coordinator)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
rfm22b_dev->coordinator = coordinator;
}
}
/**
* Sets the device coordinator ID.
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[in] coord_id The coordinator ID.
*/
void PIOS_RFM22B_SetCoordinatorID(uint32_t rfm22b_id, uint32_t coord_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (PIOS_RFM22B_Validate(rfm22b_dev)) {
rfm22b_dev->coordinatorID = coord_id;
}
}
/**
* Returns the device statistics RFM22B device.
*
* @param[in] rfm22b_id The RFM22B device index.
* @param[out] stats The stats are returned in this structure
*/
void PIOS_RFM22B_GetStats(uint32_t rfm22b_id, struct rfm22b_stats *stats)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
// Update the current stats
rfm22_updateStats(rfm22b_dev);
// Return the stats.
*stats = rfm22b_dev->stats;
}
/**
* Check the radio device for a valid connection
*
* @param[in] rfm22b_id The rfm22b device.
* @return true if there is a valid connection to paired radio, false otherwise.
*/
bool PIOS_RFM22B_LinkStatus(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return false;
}
return rfm22b_dev->stats.link_quality > RFM22B_LINK_QUALITY_THRESHOLD;
}
/**
* Put the RFM22B device into receive mode.
*
* @param[in] rfm22b_id The rfm22b device.
* @param[in] p The packet to receive into.
* @return true if Rx mode was entered sucessfully.
*/
bool PIOS_RFM22B_ReceivePacket(uint32_t rfm22b_id, uint8_t *p)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return false;
}
rfm22b_dev->rx_packet_handle = p;
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// disable interrupts
rfm22_write(rfm22b_dev, RFM22_interrupt_enable1, 0x00);
rfm22_write(rfm22b_dev, RFM22_interrupt_enable2, 0x00);
// Switch to TUNE mode
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_pllon);
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D2_LED_OFF;
#endif // PIOS_RFM22B_DEBUG_ON_TELEM
RX_LED_OFF;
TX_LED_OFF;
// empty the rx buffer
rfm22b_dev->rx_buffer_wr = 0;
// Clear the TX buffer.
rfm22b_dev->tx_data_rd = rfm22b_dev->tx_data_wr = 0;
// clear FIFOs
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl2, RFM22_opfc2_ffclrrx | RFM22_opfc2_ffclrtx);
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl2, 0x00);
// enable RX interrupts
rfm22_write(rfm22b_dev, RFM22_interrupt_enable1, RFM22_ie1_encrcerror | RFM22_ie1_enpkvalid |
RFM22_ie1_enrxffafull | RFM22_ie1_enfferr);
rfm22_write(rfm22b_dev, RFM22_interrupt_enable2, RFM22_ie2_enpreaval | RFM22_ie2_enswdet);
// enable the receiver
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_pllon | RFM22_opfc1_rxon);
// Release the SPI bus.
rfm22_releaseBus(rfm22b_dev);
// Indicate that we're in RX wait mode.
rfm22b_dev->rfm22b_state = RFM22B_STATE_RX_WAIT;
return true;
}
/**
* Transmit a packet via the RFM22B device.
*
* @param[in] rfm22b_id The rfm22b device.
* @param[in] p The packet to transmit.
* @return true if there if the packet was queued for transmission.
*/
bool PIOS_RFM22B_TransmitPacket(uint32_t rfm22b_id, uint8_t *p, uint8_t len)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return false;
}
rfm22b_dev->tx_packet_handle = p;
rfm22b_dev->packet_start_time = pios_rfm22_time_ms();
if (rfm22b_dev->packet_start_time == 0) {
rfm22b_dev->packet_start_time = 1;
}
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// Disable interrupts
rfm22_write(rfm22b_dev, RFM22_interrupt_enable1, 0x00);
rfm22_write(rfm22b_dev, RFM22_interrupt_enable2, 0x00);
// set the tx power
rfm22_write(rfm22b_dev, RFM22_tx_power, RFM22_tx_pwr_lna_sw | rfm22b_dev->tx_power);
// TUNE mode
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_pllon);
// Queue the data up for sending
rfm22b_dev->tx_data_wr = len;
RX_LED_OFF;
// Set the destination address in the transmit header.
uint32_t id = rfm22_destinationID(rfm22b_dev);
rfm22_write(rfm22b_dev, RFM22_transmit_header0, id & 0xff);
rfm22_write(rfm22b_dev, RFM22_transmit_header1, (id >> 8) & 0xff);
rfm22_write(rfm22b_dev, RFM22_transmit_header2, (id >> 16) & 0xff);
rfm22_write(rfm22b_dev, RFM22_transmit_header3, (id >> 24) & 0xff);
// FIFO mode, GFSK modulation
uint8_t fd_bit = rfm22_read(rfm22b_dev, RFM22_modulation_mode_control2) & RFM22_mmc2_fd;
rfm22_write(rfm22b_dev, RFM22_modulation_mode_control2, fd_bit | RFM22_mmc2_dtmod_fifo | RFM22_mmc2_modtyp_gfsk);
// Clear the FIFOs.
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl2, RFM22_opfc2_ffclrrx | RFM22_opfc2_ffclrtx);
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl2, 0x00);
// Set the total number of data bytes we are going to transmit.
rfm22_write(rfm22b_dev, RFM22_transmit_packet_length, len);
// Add some data to the chips TX FIFO before enabling the transmitter
uint8_t *tx_buffer = rfm22b_dev->tx_packet_handle;
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferByte(rfm22b_dev->spi_id, RFM22_fifo_access | 0x80);
int bytes_to_write = (rfm22b_dev->tx_data_wr - rfm22b_dev->tx_data_rd);
bytes_to_write = (bytes_to_write > FIFO_SIZE) ? FIFO_SIZE : bytes_to_write;
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, &tx_buffer[rfm22b_dev->tx_data_rd], NULL, bytes_to_write, NULL);
rfm22b_dev->tx_data_rd += bytes_to_write;
rfm22_deassertCs(rfm22b_dev);
// Enable TX interrupts.
rfm22_write(rfm22b_dev, RFM22_interrupt_enable1, RFM22_ie1_enpksent | RFM22_ie1_entxffaem);
// Enable the transmitter.
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_pllon | RFM22_opfc1_txon);
// Release the SPI bus.
rfm22_releaseBus(rfm22b_dev);
// We're in Tx mode.
rfm22b_dev->rfm22b_state = RFM22B_STATE_TX_MODE;
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D1_LED_ON;
#endif
return true;
}
/**
* Process a Tx interrupt from the RFM22B device.
*
* @param[in] rfm22b_id The rfm22b device.
* @return PIOS_RFM22B_TX_COMPLETE on completed Tx, or PIOS_RFM22B_INT_SUCCESS/PIOS_RFM22B_INT_FAILURE.
*/
pios_rfm22b_int_result PIOS_RFM22B_ProcessTx(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return PIOS_RFM22B_INT_FAILURE;
}
// Read the device status registers
if (!pios_rfm22_readStatus(rfm22b_dev)) {
return PIOS_RFM22B_INT_FAILURE;
}
// TX FIFO almost empty, it needs filling up
if (rfm22b_dev->status_regs.int_status_1.tx_fifo_almost_empty) {
// Add data to the TX FIFO buffer
uint8_t *tx_buffer = rfm22b_dev->tx_packet_handle;
uint16_t max_bytes = FIFO_SIZE - TX_FIFO_LO_WATERMARK - 1;
rfm22_claimBus(rfm22b_dev);
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferByte(rfm22b_dev->spi_id, RFM22_fifo_access | 0x80);
int bytes_to_write = (rfm22b_dev->tx_data_wr - rfm22b_dev->tx_data_rd);
bytes_to_write = (bytes_to_write > max_bytes) ? max_bytes : bytes_to_write;
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, &tx_buffer[rfm22b_dev->tx_data_rd], NULL, bytes_to_write, NULL);
rfm22b_dev->tx_data_rd += bytes_to_write;
rfm22_deassertCs(rfm22b_dev);
rfm22_releaseBus(rfm22b_dev);
return PIOS_RFM22B_INT_SUCCESS;
} else if (rfm22b_dev->status_regs.int_status_1.packet_sent_interrupt) {
// Transition out of Tx mode.
rfm22b_dev->rfm22b_state = RFM22B_STATE_TRANSITION;
return PIOS_RFM22B_TX_COMPLETE;
}
return 0;
}
/**
* Process a Rx interrupt from the RFM22B device.
*
* @param[in] rfm22b_id The rfm22b device.
* @return PIOS_RFM22B_RX_COMPLETE on completed Rx, or PIOS_RFM22B_INT_SUCCESS/PIOS_RFM22B_INT_FAILURE.
*/
pios_rfm22b_int_result PIOS_RFM22B_ProcessRx(uint32_t rfm22b_id)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return PIOS_RFM22B_INT_FAILURE;
}
uint8_t *rx_buffer = rfm22b_dev->rx_packet_handle;
pios_rfm22b_int_result ret = PIOS_RFM22B_INT_SUCCESS;
// Read the device status registers
if (!pios_rfm22_readStatus(rfm22b_dev)) {
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// FIFO under/over flow error. Restart RX mode.
if (rfm22b_dev->status_regs.int_status_1.fifo_underoverflow_error ||
rfm22b_dev->status_regs.int_status_1.crc_error) {
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// Valid packet received
if (rfm22b_dev->status_regs.int_status_1.valid_packet_received) {
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// read the total length of the packet data
uint32_t len = rfm22_read(rfm22b_dev, RFM22_received_packet_length);
// The received packet is going to be larger than the receive buffer
if (len > rfm22b_dev->max_packet_len) {
rfm22_releaseBus(rfm22b_dev);
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// there must still be data in the RX FIFO we need to get
if (rfm22b_dev->rx_buffer_wr < len) {
int32_t bytes_to_read = len - rfm22b_dev->rx_buffer_wr;
// Fetch the data from the RX FIFO
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferByte(rfm22b_dev->spi_id, RFM22_fifo_access & 0x7F);
rfm22b_dev->rx_buffer_wr += (PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, OUT_FF, (uint8_t *)&rx_buffer[rfm22b_dev->rx_buffer_wr],
bytes_to_read, NULL) == 0) ? bytes_to_read : 0;
rfm22_deassertCs(rfm22b_dev);
}
// Read the packet header (destination ID)
rfm22b_dev->rx_destination_id = rfm22_read(rfm22b_dev, RFM22_received_header0);
rfm22b_dev->rx_destination_id |= (rfm22_read(rfm22b_dev, RFM22_received_header1) << 8);
rfm22b_dev->rx_destination_id |= (rfm22_read(rfm22b_dev, RFM22_received_header2) << 16);
rfm22b_dev->rx_destination_id |= (rfm22_read(rfm22b_dev, RFM22_received_header3) << 24);
// Release the SPI bus.
rfm22_releaseBus(rfm22b_dev);
// Is there a length error?
if (rfm22b_dev->rx_buffer_wr != len) {
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// Increment the total byte received count.
rfm22b_dev->stats.rx_byte_count += rfm22b_dev->rx_buffer_wr;
// We're finished with Rx mode
rfm22b_dev->rfm22b_state = RFM22B_STATE_TRANSITION;
ret = PIOS_RFM22B_RX_COMPLETE;
} else if (rfm22b_dev->status_regs.int_status_1.rx_fifo_almost_full) {
// RX FIFO almost full, it needs emptying
// read data from the rf chips FIFO buffer
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// Read the total length of the packet data
uint16_t len = rfm22_read(rfm22b_dev, RFM22_received_packet_length);
// The received packet is going to be larger than the specified length
if ((rfm22b_dev->rx_buffer_wr + RX_FIFO_HI_WATERMARK) > len) {
rfm22_releaseBus(rfm22b_dev);
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// The received packet is going to be larger than the receive buffer
if ((rfm22b_dev->rx_buffer_wr + RX_FIFO_HI_WATERMARK) > rfm22b_dev->max_packet_len) {
rfm22_releaseBus(rfm22b_dev);
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
// Fetch the data from the RX FIFO
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferByte(rfm22b_dev->spi_id, RFM22_fifo_access & 0x7F);
rfm22b_dev->rx_buffer_wr += (PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, OUT_FF, (uint8_t *)&rx_buffer[rfm22b_dev->rx_buffer_wr],
RX_FIFO_HI_WATERMARK, NULL) == 0) ? RX_FIFO_HI_WATERMARK : 0;
rfm22_deassertCs(rfm22b_dev);
// Release the SPI bus.
rfm22_releaseBus(rfm22b_dev);
// Make sure that we're in RX mode.
rfm22b_dev->rfm22b_state = RFM22B_STATE_RX_MODE;
} else if (rfm22b_dev->status_regs.int_status_2.valid_preamble_detected) {
// Valid preamble detected
RX_LED_ON;
// Sync word detected
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D2_LED_ON;
#endif // PIOS_RFM22B_DEBUG_ON_TELEM
rfm22b_dev->packet_start_time = pios_rfm22_time_ms();
if (rfm22b_dev->packet_start_time == 0) {
rfm22b_dev->packet_start_time = 1;
}
// We detected the preamble, now wait for sync.
rfm22b_dev->rfm22b_state = RFM22B_STATE_RX_WAIT_SYNC;
} else if (rfm22b_dev->status_regs.int_status_2.sync_word_detected) {
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// read the 10-bit signed afc correction value
// bits 9 to 2
int16_t afc_correction = (uint16_t)rfm22_read(rfm22b_dev, RFM22_afc_correction_read) << 8;
// bits 1 & 0
afc_correction |= (int16_t)rfm22_read(rfm22b_dev, RFM22_ook_counter_value1) & 0x00c0;
afc_correction >>= 6;
// convert the afc value to Hz
int32_t afc_corr = (int32_t)(rfm22b_dev->frequency_step_size * afc_correction + 0.5f);
rfm22b_dev->afc_correction_Hz = afc_corr;
// read rx signal strength .. 45 = -100dBm, 205 = -20dBm
uint8_t rssi = rfm22_read(rfm22b_dev, RFM22_rssi);
// convert to dBm
rfm22b_dev->rssi_dBm = (int8_t)(rssi >> 1) - 122;
// Release the SPI bus.
rfm22_releaseBus(rfm22b_dev);
// Indicate that we're in RX mode.
rfm22b_dev->rfm22b_state = RFM22B_STATE_RX_MODE;
} else if ((rfm22b_dev->rfm22b_state == RFM22B_STATE_RX_WAIT_SYNC) && !rfm22b_dev->status_regs.int_status_2.valid_preamble_detected) {
// Waiting for the preamble timed out.
rfm22_rxFailure(rfm22b_dev);
return PIOS_RFM22B_INT_FAILURE;
}
return ret;
}
/**
* Set the PPM packet received callback.
*
* @param[in] rfm22b_dev The RFM22B device ID.
* @param[in] cb The callback function pointer.
*/
void PIOS_RFM22B_SetPPMCallback(uint32_t rfm22b_id, PPMReceivedCallback cb, uint32_t cb_context)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
/*
* Order is important in these assignments since rfm22_task uses ppm_callback
* field to determine if it's ok to dereference ppm_callback and ppm_context
*/
rfm22b_dev->ppm_context = cb_context;
rfm22b_dev->ppm_callback = cb;
}
/**
* Set the PPM values to be transmitted.
*
* @param[in] rfm22b_dev The RFM22B device ID.
* @param[in] channels The PPM channel values.
* @param[out] nchan The number of channels to set.
*/
extern void PIOS_RFM22B_PPMSet(uint32_t rfm22b_id, int16_t *channels, uint8_t nchan)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS; ++i) {
rfm22b_dev->ppm[i] = (i < nchan) ? channels[i] : PIOS_RCVR_INVALID;
}
}
/**
* Fetch the PPM values that have been received.
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
* @param[out] channels The PPM channel values.
* @param[out] nchan The number of channels to get.
*/
extern void PIOS_RFM22B_PPMGet(uint32_t rfm22b_id, int16_t *channels, uint8_t nchan)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)rfm22b_id;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
if (!rfm22_isCoordinator(rfm22b_dev) && !rfm22_isConnected(rfm22b_dev)) {
// Set the PPM channels values to INVALID
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS; ++i) {
channels[i] = PIOS_RCVR_INVALID;
}
return;
}
for (uint8_t i = 0; i < nchan; ++i) {
channels[i] = (i < RFM22B_PPM_NUM_CHANNELS) ? rfm22b_dev->ppm[i] : PIOS_RCVR_INVALID;
}
}
/**
* Validate that the device structure is valid.
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
*/
inline bool PIOS_RFM22B_Validate(struct pios_rfm22b_dev *rfm22b_dev)
{
return rfm22b_dev != NULL && rfm22b_dev->magic == PIOS_RFM22B_DEV_MAGIC;
}
/*****************************************************************************
* The Device Control Thread
*****************************************************************************/
/**
* The task that controls the radio state machine.
*
* @param[in] paramters The task parameters.
*/
static void pios_rfm22_task(void *parameters)
{
struct pios_rfm22b_dev *rfm22b_dev = (struct pios_rfm22b_dev *)parameters;
if (!PIOS_RFM22B_Validate(rfm22b_dev)) {
return;
}
uint32_t lastEventTime = pios_rfm22_time_ms();
while (1) {
#if defined(PIOS_INCLUDE_WDG) && defined(PIOS_WDG_RFM22B)
// Update the watchdog timer
PIOS_WDG_UpdateFlag(PIOS_WDG_RFM22B);
#endif /* PIOS_WDG_RFM22B */
// Wait for a signal indicating an external interrupt or a pending send/receive request.
if (xSemaphoreTake(rfm22b_dev->isrPending, ISR_TIMEOUT / portTICK_RATE_MS) == pdTRUE) {
lastEventTime = pios_rfm22_time_ms();
// Process events through the state machine.
enum pios_radio_event event;
while (xQueueReceive(rfm22b_dev->eventQueue, &event, 0) == pdTRUE) {
if ((event == RADIO_EVENT_INT_RECEIVED) &&
((rfm22b_dev->state == RADIO_STATE_UNINITIALIZED) || (rfm22b_dev->state == RADIO_STATE_INITIALIZING))) {
continue;
}
rfm22_process_event(rfm22b_dev, event);
}
} else {
// Has it been too long since the last event?
uint32_t curTime = pios_rfm22_time_ms();
if (pios_rfm22_time_difference_ms(lastEventTime, curTime) > PIOS_RFM22B_SUPERVISOR_TIMEOUT) {
// Clear the event queue.
enum pios_radio_event event;
while (xQueueReceive(rfm22b_dev->eventQueue, &event, 0) == pdTRUE) {
// Do nothing;
}
lastEventTime = pios_rfm22_time_ms();
// Transsition through an error event.
rfm22_process_event(rfm22b_dev, RADIO_EVENT_ERROR);
}
}
// Change channels if necessary.
if (rfm22_changeChannel(rfm22b_dev)) {
rfm22_process_event(rfm22b_dev, RADIO_EVENT_RX_MODE);
}
// Have we been sending / receiving this packet too long?
uint32_t curTime = pios_rfm22_time_ms();
if ((rfm22b_dev->packet_start_time > 0) &&
(pios_rfm22_time_difference_ms(rfm22b_dev->packet_start_time, curTime) > (rfm22b_dev->packet_time * 3))) {
rfm22_process_event(rfm22b_dev, RADIO_EVENT_TIMEOUT);
}
// Start transmitting a packet if it's time.
bool time_to_send = rfm22_timeToSend(rfm22b_dev);
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
if (time_to_send) {
D4_LED_ON;
} else {
D4_LED_OFF;
}
#endif
if (time_to_send && PIOS_RFM22B_InRxWait((uint32_t)rfm22b_dev)) {
rfm22_process_event(rfm22b_dev, RADIO_EVENT_TX_START);
}
}
}
/*****************************************************************************
* The State Machine Functions
*****************************************************************************/
/**
* Inject an event into the RFM22B state machine.
*
* @param[in] rfm22b_dev The device structure
* @param[in] event The event to inject
* @param[in] inISR Is this being called from an interrrup service routine?
*/
static void pios_rfm22_inject_event(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event, bool inISR)
{
if (inISR) {
// Store the event.
portBASE_TYPE pxHigherPriorityTaskWoken1;
if (xQueueSendFromISR(rfm22b_dev->eventQueue, &event, &pxHigherPriorityTaskWoken1) != pdTRUE) {
return;
}
// Signal the semaphore to wake up the handler thread.
portBASE_TYPE pxHigherPriorityTaskWoken2;
if (xSemaphoreGiveFromISR(rfm22b_dev->isrPending, &pxHigherPriorityTaskWoken2) != pdTRUE) {
// Something went fairly seriously wrong
rfm22b_dev->errors++;
}
portEND_SWITCHING_ISR((pxHigherPriorityTaskWoken1 == pdTRUE) || (pxHigherPriorityTaskWoken2 == pdTRUE));
} else {
// Store the event.
if (xQueueSend(rfm22b_dev->eventQueue, &event, portMAX_DELAY) != pdTRUE) {
return;
}
// Signal the semaphore to wake up the handler thread.
if (xSemaphoreGive(rfm22b_dev->isrPending) != pdTRUE) {
// Something went fairly seriously wrong
rfm22b_dev->errors++;
}
}
}
/**
* Process the next state transition from the given event.
*
* @param[in] rfm22b_dev The device structure
* @param[in] event The event to process
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_process_state_transition(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event)
{
// No event
if (event >= RADIO_EVENT_NUM_EVENTS) {
return RADIO_EVENT_NUM_EVENTS;
}
// Don't transition if there is no transition defined
enum pios_radio_state next_state = rfm22b_transitions[rfm22b_dev->state].next_state[event];
if (!next_state) {
return RADIO_EVENT_NUM_EVENTS;
}
/*
* Move to the next state
*
* This is done prior to calling the new state's entry function to
* guarantee that the entry function never depends on the previous
* state. This way, it cannot ever know what the previous state was.
*/
rfm22b_dev->state = next_state;
/* Call the entry function (if any) for the next state. */
if (rfm22b_transitions[rfm22b_dev->state].entry_fn) {
return rfm22b_transitions[rfm22b_dev->state].entry_fn(rfm22b_dev);
}
return RADIO_EVENT_NUM_EVENTS;
}
/**
* Process the given event through the state transition table.
* This could cause a series of events and transitions to take place.
*
* @param[in] rfm22b_dev The device structure
* @param[in] event The event to process
*/
static void rfm22_process_event(struct pios_rfm22b_dev *rfm22b_dev, enum pios_radio_event event)
{
// Process all state transitions.
while (event != RADIO_EVENT_NUM_EVENTS) {
event = rfm22_process_state_transition(rfm22b_dev, event);
}
}
/*****************************************************************************
* The Device Initialization / Configuration Functions
*****************************************************************************/
/**
* Initialize (or re-initialize) the RFM22B radio device.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_init(struct pios_rfm22b_dev *rfm22b_dev)
{
// Initialize the register values.
rfm22b_dev->status_regs.int_status_1.raw = 0;
rfm22b_dev->status_regs.int_status_2.raw = 0;
rfm22b_dev->status_regs.device_status.raw = 0;
rfm22b_dev->status_regs.ezmac_status.raw = 0;
// Clean the LEDs
rfm22_clearLEDs();
// Initlize the link stats.
for (uint8_t i = 0; i < RFM22B_RX_PACKET_STATS_LEN; ++i) {
rfm22b_dev->rx_packet_stats[i] = 0;
}
// Initialize the state
rfm22b_dev->stats.link_state = OPLINKSTATUS_LINKSTATE_ENABLED;
// Initialize the packets.
rfm22b_dev->rx_packet_len = 0;
rfm22b_dev->rx_destination_id = 0;
rfm22b_dev->tx_packet_handle = NULL;
// Initialize the devide state
rfm22b_dev->rx_buffer_wr = 0;
rfm22b_dev->tx_data_rd = rfm22b_dev->tx_data_wr = 0;
rfm22b_dev->channel = 0;
rfm22b_dev->channel_index = 0;
rfm22b_dev->afc_correction_Hz = 0;
rfm22b_dev->packet_start_time = 0;
rfm22b_dev->rfm22b_state = RFM22B_STATE_INITIALIZING;
rfm22b_dev->last_contact = 0;
// software reset the RF chip .. following procedure according to Si4x3x Errata (rev. B)
rfm22_write_claim(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_swres);
for (uint8_t i = 0; i < 50; ++i) {
// read the status registers
pios_rfm22_readStatus(rfm22b_dev);
// Is the chip ready?
if (rfm22b_dev->status_regs.int_status_2.chip_ready) {
break;
}
// Wait 1ms if not.
vTaskDelay(1 + (1 / (portTICK_RATE_MS + 1)));
}
// ****************
// read status - clears interrupt
pios_rfm22_readStatus(rfm22b_dev);
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// disable all interrupts
rfm22_write(rfm22b_dev, RFM22_interrupt_enable1, 0x00);
rfm22_write(rfm22b_dev, RFM22_interrupt_enable2, 0x00);
// read the RF chip ID bytes
// read the device type
uint8_t device_type = rfm22_read(rfm22b_dev, RFM22_DEVICE_TYPE) & RFM22_DT_MASK;
// read the device version
uint8_t device_version = rfm22_read(rfm22b_dev, RFM22_DEVICE_VERSION) & RFM22_DV_MASK;
#if defined(RFM22_DEBUG)
DEBUG_PRINTF(2, "rf device type: %d\n\r", device_type);
DEBUG_PRINTF(2, "rf device version: %d\n\r", device_version);
#endif
if (device_type != 0x08) {
#if defined(RFM22_DEBUG)
DEBUG_PRINTF(2, "rf device type: INCORRECT - should be 0x08\n\r");
#endif
// incorrect RF module type
return RADIO_EVENT_FATAL_ERROR;
}
if (device_version != RFM22_DEVICE_VERSION_B1) {
#if defined(RFM22_DEBUG)
DEBUG_PRINTF(2, "rf device version: INCORRECT\n\r");
#endif
// incorrect RF module version
return RADIO_EVENT_FATAL_ERROR;
}
// calibrate our RF module to be exactly on frequency .. different for every module
rfm22_write(rfm22b_dev, RFM22_xtal_osc_load_cap, OSC_LOAD_CAP);
// disable Low Duty Cycle Mode
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl2, 0x00);
// 1MHz clock output
rfm22_write(rfm22b_dev, RFM22_cpu_output_clk, RFM22_coc_1MHz);
// READY mode
rfm22_write(rfm22b_dev, RFM22_op_and_func_ctrl1, RFM22_opfc1_xton);
// choose the 3 GPIO pin functions
// GPIO port use default value
rfm22_write(rfm22b_dev, RFM22_io_port_config, RFM22_io_port_default);
if (rfm22b_dev->cfg.gpio_direction == GPIO0_TX_GPIO1_RX) {
// GPIO0 = TX State (to control RF Switch)
rfm22_write(rfm22b_dev, RFM22_gpio0_config, RFM22_gpio0_config_drv3 | RFM22_gpio0_config_txstate);
// GPIO1 = RX State (to control RF Switch)
rfm22_write(rfm22b_dev, RFM22_gpio1_config, RFM22_gpio1_config_drv3 | RFM22_gpio1_config_rxstate);
} else {
// GPIO0 = TX State (to control RF Switch)
rfm22_write(rfm22b_dev, RFM22_gpio0_config, RFM22_gpio0_config_drv3 | RFM22_gpio0_config_rxstate);
// GPIO1 = RX State (to control RF Switch)
rfm22_write(rfm22b_dev, RFM22_gpio1_config, RFM22_gpio1_config_drv3 | RFM22_gpio1_config_txstate);
}
// GPIO2 = Clear Channel Assessment
rfm22_write(rfm22b_dev, RFM22_gpio2_config, RFM22_gpio2_config_drv3 | RFM22_gpio2_config_cca);
// FIFO mode, GFSK modulation
uint8_t fd_bit = rfm22_read(rfm22b_dev, RFM22_modulation_mode_control2) & RFM22_mmc2_fd;
rfm22_write(rfm22b_dev, RFM22_modulation_mode_control2, RFM22_mmc2_trclk_clk_none | RFM22_mmc2_dtmod_fifo | fd_bit | RFM22_mmc2_modtyp_gfsk);
// setup to read the internal temperature sensor
// ADC used to sample the temperature sensor
uint8_t adc_config = RFM22_ac_adcsel_temp_sensor | RFM22_ac_adcref_bg;
rfm22_write(rfm22b_dev, RFM22_adc_config, adc_config);
// adc offset
rfm22_write(rfm22b_dev, RFM22_adc_sensor_amp_offset, 0);
// temp sensor calibration .. �40C to +64C 0.5C resolution
rfm22_write(rfm22b_dev, RFM22_temp_sensor_calib, RFM22_tsc_tsrange0 | RFM22_tsc_entsoffs);
// temp sensor offset
rfm22_write(rfm22b_dev, RFM22_temp_value_offset, 0);
// start an ADC conversion
rfm22_write(rfm22b_dev, RFM22_adc_config, adc_config | RFM22_ac_adcstartbusy);
// set the RSSI threshold interrupt to about -90dBm
rfm22_write(rfm22b_dev, RFM22_rssi_threshold_clear_chan_indicator, (-90 + 122) * 2);
// enable the internal Tx & Rx packet handlers (without CRC)
rfm22_write(rfm22b_dev, RFM22_data_access_control, RFM22_dac_enpacrx | RFM22_dac_enpactx);
// x-nibbles tx preamble
rfm22_write(rfm22b_dev, RFM22_preamble_length, TX_PREAMBLE_NIBBLES);
// x-nibbles rx preamble detection
rfm22_write(rfm22b_dev, RFM22_preamble_detection_ctrl1, RX_PREAMBLE_NIBBLES << 3);
// Release the bus
rfm22_releaseBus(rfm22b_dev);
// Yield the CPU.
vTaskDelay(1 + (1 / (portTICK_RATE_MS + 1)));
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// header control - using a 4 by header with broadcast of 0xffffffff
rfm22_write(rfm22b_dev, RFM22_header_control1,
RFM22_header_cntl1_bcen_0 |
RFM22_header_cntl1_bcen_1 |
RFM22_header_cntl1_bcen_2 |
RFM22_header_cntl1_bcen_3 |
RFM22_header_cntl1_hdch_0 |
RFM22_header_cntl1_hdch_1 |
RFM22_header_cntl1_hdch_2 |
RFM22_header_cntl1_hdch_3);
// Check all bit of all bytes of the header, unless we're an unbound modem.
uint8_t header_mask = (rfm22_destinationID(rfm22b_dev) == 0xffffffff) ? 0 : 0xff;
rfm22_write(rfm22b_dev, RFM22_header_enable0, header_mask);
rfm22_write(rfm22b_dev, RFM22_header_enable1, header_mask);
rfm22_write(rfm22b_dev, RFM22_header_enable2, header_mask);
rfm22_write(rfm22b_dev, RFM22_header_enable3, header_mask);
// The destination ID and receive ID should be the same.
uint32_t id = rfm22_destinationID(rfm22b_dev);
rfm22_write(rfm22b_dev, RFM22_check_header0, id & 0xff);
rfm22_write(rfm22b_dev, RFM22_check_header1, (id >> 8) & 0xff);
rfm22_write(rfm22b_dev, RFM22_check_header2, (id >> 16) & 0xff);
rfm22_write(rfm22b_dev, RFM22_check_header3, (id >> 24) & 0xff);
// 4 header bytes, synchronization word length 3, 2, 1 & 0 used, packet length included in header.
rfm22_write(rfm22b_dev, RFM22_header_control2,
RFM22_header_cntl2_hdlen_3210 |
RFM22_header_cntl2_synclen_3210 |
((TX_PREAMBLE_NIBBLES >> 8) & 0x01));
// sync word
rfm22_write(rfm22b_dev, RFM22_sync_word3, SYNC_BYTE_1);
rfm22_write(rfm22b_dev, RFM22_sync_word2, SYNC_BYTE_2);
rfm22_write(rfm22b_dev, RFM22_sync_word1, SYNC_BYTE_3);
rfm22_write(rfm22b_dev, RFM22_sync_word0, SYNC_BYTE_4);
// TX FIFO Almost Full Threshold (0 - 63)
rfm22_write(rfm22b_dev, RFM22_tx_fifo_control1, TX_FIFO_HI_WATERMARK);
// TX FIFO Almost Empty Threshold (0 - 63)
rfm22_write(rfm22b_dev, RFM22_tx_fifo_control2, TX_FIFO_LO_WATERMARK);
// RX FIFO Almost Full Threshold (0 - 63)
rfm22_write(rfm22b_dev, RFM22_rx_fifo_control, RX_FIFO_HI_WATERMARK);
// Set the xtal capacitor for frequency calibration
// Cint = 1.8 pF + 0.085 pF x xlc[6:0] + 3.7 pF x xlc[7] (xtalshift)
// cfg.RFXtalCap 0 to 171 range give Cint = 1.8pF to 16.295pF range
// Default is 127, equal to 12.595pF
rfm22_write(rfm22b_dev,
RFM22_xtal_osc_load_cap,
(rfm22b_dev->cfg.RFXtalCap < 128) ? rfm22b_dev->cfg.RFXtalCap : (rfm22b_dev->cfg.RFXtalCap + 84));
// Release the bus
rfm22_releaseBus(rfm22b_dev);
// Yield the CPU.
vTaskDelay(1 + (1 / (portTICK_RATE_MS + 1)));
// Initialize the frequency and datarate to te default.
rfm22_setNominalCarrierFrequency(rfm22b_dev, 0, rfm22b_dev->base_freq);
pios_rfm22_setDatarate(rfm22b_dev);
return RADIO_EVENT_INITIALIZED;
}
/**
* Set the air datarate for the RFM22B device.
*
* Carson's rule:
* The signal bandwidth is about 2(Delta-f + fm) ..
*
* Delta-f = frequency deviation
* fm = maximum frequency of the signal
*
* @param[in] rfm33b_dev The device structure pointer.
* @param[in] datarate The air datarate.
* @param[in] data_whitening Is data whitening desired?
*/
static void pios_rfm22_setDatarate(struct pios_rfm22b_dev *rfm22b_dev)
{
enum rfm22b_datarate datarate = rfm22b_dev->datarate;
bool data_whitening = true;
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// rfm22_if_filter_bandwidth
rfm22_write(rfm22b_dev, 0x1C, reg_1C[datarate]);
// rfm22_afc_loop_gearshift_override
rfm22_write(rfm22b_dev, 0x1D, reg_1D[datarate]);
// RFM22_afc_timing_control
rfm22_write(rfm22b_dev, 0x1E, reg_1E[datarate]);
// RFM22_clk_recovery_gearshift_override
rfm22_write(rfm22b_dev, 0x1F, reg_1F[datarate]);
// rfm22_clk_recovery_oversampling_ratio
rfm22_write(rfm22b_dev, 0x20, reg_20[datarate]);
// rfm22_clk_recovery_offset2
rfm22_write(rfm22b_dev, 0x21, reg_21[datarate]);
// rfm22_clk_recovery_offset1
rfm22_write(rfm22b_dev, 0x22, reg_22[datarate]);
// rfm22_clk_recovery_offset0
rfm22_write(rfm22b_dev, 0x23, reg_23[datarate]);
// rfm22_clk_recovery_timing_loop_gain1
rfm22_write(rfm22b_dev, 0x24, reg_24[datarate]);
// rfm22_clk_recovery_timing_loop_gain0
rfm22_write(rfm22b_dev, 0x25, reg_25[datarate]);
// rfm22_agc_override1
rfm22_write(rfm22b_dev, RFM22_agc_override1, reg_69[datarate]);
// rfm22_afc_limiter
rfm22_write(rfm22b_dev, 0x2A, reg_2A[datarate]);
// rfm22_tx_data_rate1
rfm22_write(rfm22b_dev, 0x6E, reg_6E[datarate]);
// rfm22_tx_data_rate0
rfm22_write(rfm22b_dev, 0x6F, reg_6F[datarate]);
if (!data_whitening) {
// rfm22_modulation_mode_control1
rfm22_write(rfm22b_dev, 0x70, reg_70[datarate] & ~RFM22_mmc1_enwhite);
} else {
// rfm22_modulation_mode_control1
rfm22_write(rfm22b_dev, 0x70, reg_70[datarate] | RFM22_mmc1_enwhite);
}
// rfm22_modulation_mode_control2
rfm22_write(rfm22b_dev, 0x71, reg_71[datarate]);
// rfm22_frequency_deviation
rfm22_write(rfm22b_dev, 0x72, reg_72[datarate]);
// rfm22_cpcuu
rfm22_write(rfm22b_dev, 0x58, reg_58[datarate]);
rfm22_write(rfm22b_dev, RFM22_ook_counter_value1, 0x00);
rfm22_write(rfm22b_dev, RFM22_ook_counter_value2, 0x00);
// Release the bus
rfm22_releaseBus(rfm22b_dev);
}
/**
* Set the nominal carrier frequency, channel step size, and initial channel
*
* @param[in] rfm33b_dev The device structure pointer.
* @param[in] init_chan The initial channel to tune to.
*/
static void rfm22_setNominalCarrierFrequency(struct pios_rfm22b_dev *rfm22b_dev, uint8_t init_chan, uint32_t frequency_hz)
{
// The step size is 10MHz / 250 = 40khz, and the step size is specified in 10khz increments.
uint8_t freq_hop_step_size = 4;
// holds the hbsel (1 or 2)
uint8_t hbsel;
if (frequency_hz < 480000000) {
hbsel = 0;
} else {
hbsel = 1;
}
float freq_mhz = (float)(frequency_hz) / 1000000.0f;
float xtal_freq_khz = 30000.0f;
float sfreq = freq_mhz / (10.0f * (xtal_freq_khz / 30000.0f) * (1 + hbsel));
uint32_t fb = (uint32_t)sfreq - 24 + (64 + 32 * hbsel);
uint32_t fc = (uint32_t)((sfreq - (uint32_t)sfreq) * 64000.0f);
uint8_t fch = (fc >> 8) & 0xff;
uint8_t fcl = fc & 0xff;
// Claim the SPI bus.
rfm22_claimBus(rfm22b_dev);
// Set the frequency hopping step size.
rfm22_write(rfm22b_dev, RFM22_frequency_hopping_step_size, freq_hop_step_size);
// frequency step
rfm22b_dev->frequency_step_size = 156.25f * (hbsel + 1);
// frequency hopping channel (0-255)
rfm22b_dev->channel = init_chan;
rfm22_write(rfm22b_dev, RFM22_frequency_hopping_channel_select, init_chan);
// no frequency offset
rfm22_write(rfm22b_dev, RFM22_frequency_offset1, 0);
rfm22_write(rfm22b_dev, RFM22_frequency_offset2, 0);
// set the carrier frequency
rfm22_write(rfm22b_dev, RFM22_frequency_band_select, fb & 0xff);
rfm22_write(rfm22b_dev, RFM22_nominal_carrier_frequency1, fch);
rfm22_write(rfm22b_dev, RFM22_nominal_carrier_frequency0, fcl);
// Release the bus
rfm22_releaseBus(rfm22b_dev);
}
/**
* Set the frequency hopping channel.
*
* @param[in] rfm33b_dev The device structure pointer.
*/
static bool rfm22_setFreqHopChannel(struct pios_rfm22b_dev *rfm22b_dev, uint8_t channel)
{
// set the frequency hopping channel
if (rfm22b_dev->channel == channel) {
return false;
}
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D3_LED_TOGGLE;
#endif // PIOS_RFM22B_DEBUG_ON_TELEM
rfm22b_dev->channel = channel;
rfm22_write_claim(rfm22b_dev, RFM22_frequency_hopping_channel_select, channel);
return true;
}
/**
* Generate the unique device ID for the RFM22B device.
*
* @param[in] rfm22b_id The RFM22B device index.
*
*/
void rfm22_generateDeviceID(struct pios_rfm22b_dev *rfm22b_dev)
{
// Create our (hopefully) unique 32 bit id from the processor serial number.
uint8_t crcs[] = { 0, 0, 0, 0 };
{
char serial_no_str[33];
PIOS_SYS_SerialNumberGet(serial_no_str);
// Create a 32 bit value using 4 8 bit CRC values.
for (uint8_t i = 0; serial_no_str[i] != 0; ++i) {
crcs[i % 4] = PIOS_CRC_updateByte(crcs[i % 4], serial_no_str[i]);
}
}
rfm22b_dev->deviceID = crcs[0] | crcs[1] << 8 | crcs[2] << 16 | crcs[3] << 24;
DEBUG_PRINTF(2, "Generated RF device ID: %x\n\r", rfm22b_dev->deviceID);
}
/**
* Read the RFM22B interrupt and device status registers
*
* @param[in] rfm22b_dev The device structure
*/
static bool pios_rfm22_readStatus(struct pios_rfm22b_dev *rfm22b_dev)
{
// 1. Read the interrupt statuses with burst read
rfm22_claimBus(rfm22b_dev); // Set RC and the semaphore
uint8_t write_buf[3] = { RFM22_interrupt_status1 &0x7f, 0xFF, 0xFF };
uint8_t read_buf[3];
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, write_buf, read_buf, sizeof(write_buf), NULL);
rfm22_deassertCs(rfm22b_dev);
rfm22b_dev->status_regs.int_status_1.raw = read_buf[1];
rfm22b_dev->status_regs.int_status_2.raw = read_buf[2];
// Device status
rfm22b_dev->status_regs.device_status.raw = rfm22_read(rfm22b_dev, RFM22_device_status);
// EzMAC status
rfm22b_dev->status_regs.ezmac_status.raw = rfm22_read(rfm22b_dev, RFM22_ezmac_status);
// Release the bus
rfm22_releaseBus(rfm22b_dev);
// the RF module has gone and done a reset - we need to re-initialize the rf module
if (rfm22b_dev->status_regs.int_status_2.poweron_reset) {
return false;
}
return true;
}
/**
* Recover from a failure in receiving a packet.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static void rfm22_rxFailure(struct pios_rfm22b_dev *rfm22b_dev)
{
rfm22b_add_rx_status(rfm22b_dev, RADIO_FAILURE_RX_PACKET);
rfm22b_dev->rx_buffer_wr = 0;
rfm22b_dev->packet_start_time = 0;
rfm22b_dev->rfm22b_state = RFM22B_STATE_TRANSITION;
}
/*****************************************************************************
* Radio Transmit and Receive functions.
*****************************************************************************/
/**
* Start a transmit if possible
*
* @param[in] radio_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event radio_txStart(struct pios_rfm22b_dev *radio_dev)
{
uint8_t *p = radio_dev->tx_packet;
uint8_t len = 0;
uint8_t max_data_len = radio_dev->max_packet_len - (radio_dev->ppm_only_mode ? 0 : RS_ECC_NPARITY);
// Don't send if it's not our turn, or if we're receiving a packet.
if (!rfm22_timeToSend(radio_dev) || !PIOS_RFM22B_InRxWait((uint32_t)radio_dev)) {
return RADIO_EVENT_RX_MODE;
}
// Don't send anything if we're bound to a coordinator and not yet connected.
if (!rfm22_isCoordinator(radio_dev) && !rfm22_isConnected(radio_dev)) {
return RADIO_EVENT_RX_MODE;
}
// Should we append PPM data to the packet?
if (radio_dev->ppm_send_mode) {
len = RFM22B_PPM_NUM_CHANNELS + (radio_dev->ppm_only_mode ? 2 : 1);
// Ensure we can fit the PPM data in the packet.
if (max_data_len < len) {
return RADIO_EVENT_RX_MODE;
}
// The first byte stores the LSB of each channel
p[0] = 0;
// Read the PPM input.
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS; ++i) {
int32_t val = radio_dev->ppm[i];
// Clamp and translate value, or transmit as reserved "invalid" constant
if ((val == PIOS_RCVR_INVALID) || (val == PIOS_RCVR_TIMEOUT)) {
val = RFM22B_PPM_INVALID;
} else if (val > RFM22B_PPM_MAX_US) {
val = RFM22B_PPM_MAX;
} else if (val < RFM22B_PPM_MIN_US) {
val = RFM22B_PPM_MIN;
} else {
val = (val - RFM22B_PPM_MIN_US) / RFM22B_PPM_SCALE + RFM22B_PPM_MIN;
}
// Store LSB
if (val & 1) {
p[0] |= (1 << i);
}
// Store upper 8 bits in array
p[i + 1] = val >> 1;
}
// The last byte is a CRC.
if (radio_dev->ppm_only_mode) {
uint8_t crc = 0;
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS + 1; ++i) {
crc = PIOS_CRC_updateByte(crc, p[i]);
}
p[RFM22B_PPM_NUM_CHANNELS + 1] = crc;
}
}
// Append data from the com interface if applicable.
if (!radio_dev->ppm_only_mode) {
uint8_t newlen = 0;
bool need_yield = false;
uint8_t i = 0;
// Try to get some data to send
while (newlen == 0 && i < 2) {
radio_dev->last_stream_sent = (radio_dev->last_stream_sent + 1) % 2;
if (!radio_dev->last_stream_sent) {
if (radio_dev->tx_out_cb) {
newlen = (radio_dev->tx_out_cb)(radio_dev->tx_out_context, p + len + 1, max_data_len - len - 1, NULL, &need_yield);
}
} else {
if (radio_dev->aux_tx_out_cb) {
newlen = (radio_dev->aux_tx_out_cb)(radio_dev->aux_tx_out_context, p + len + 1, max_data_len - len - 1, NULL, &need_yield);
}
}
i++;
}
if (newlen) {
*(p + len) = radio_dev->last_stream_sent;
len += newlen + 1;
}
}
// Always send a packet if this modem is a coordinator.
if ((len == 0) && !rfm22_isCoordinator(radio_dev)) {
return RADIO_EVENT_RX_MODE;
}
// Increment the packet sequence number.
radio_dev->stats.tx_seq++;
// Add the error correcting code.
if (!radio_dev->ppm_only_mode) {
if (len != 0) {
encode_data((unsigned char *)p, len, (unsigned char *)p);
}
len += RS_ECC_NPARITY;
}
// Only count the packet if it contains valid data.
if (radio_dev->ppm_only_mode || (len > RS_ECC_NPARITY)) {
TX_LED_ON;
radio_dev->stats.tx_byte_count += len;
}
// Transmit the packet.
PIOS_RFM22B_TransmitPacket((uint32_t)radio_dev, p, len);
return RADIO_EVENT_NUM_EVENTS;
}
/**
* Transmit packet data.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event radio_txData(struct pios_rfm22b_dev *radio_dev)
{
enum pios_radio_event ret_event = RADIO_EVENT_NUM_EVENTS;
pios_rfm22b_int_result res = PIOS_RFM22B_ProcessTx((uint32_t)radio_dev);
// Is the transmition complete
if (res == PIOS_RFM22B_TX_COMPLETE) {
// Is this an ACK?
ret_event = RADIO_EVENT_RX_MODE;
radio_dev->tx_packet_handle = 0;
radio_dev->tx_data_wr = radio_dev->tx_data_rd = 0;
// Start a new transaction
radio_dev->packet_start_time = 0;
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D1_LED_OFF;
#endif
}
return ret_event;
}
/**
* Switch the radio into receive mode.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event radio_setRxMode(struct pios_rfm22b_dev *rfm22b_dev)
{
if (!PIOS_RFM22B_ReceivePacket((uint32_t)rfm22b_dev, rfm22b_dev->rx_packet)) {
return RADIO_EVENT_NUM_EVENTS;
}
rfm22b_dev->packet_start_time = 0;
// No event generated
return RADIO_EVENT_NUM_EVENTS;
}
/**
* Complete the receipt of a packet.
*
* @param[in] radio_dev The device structure
* @param[in] p The packet handle of the received packet.
* @param[in] rc_len The number of bytes received.
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event radio_receivePacket(struct pios_rfm22b_dev *radio_dev, uint8_t *p, uint16_t rx_len)
{
bool good_packet = true;
bool corrected_packet = false;
uint8_t stream_num = 0;
uint8_t data_len = rx_len;
// We don't rsencode ppm only packets.
if (!radio_dev->ppm_only_mode) {
data_len -= RS_ECC_NPARITY;
// Attempt to correct any errors in the packet.
if (data_len > 0) {
decode_data((unsigned char *)p, rx_len);
good_packet = check_syndrome() == 0;
// We have an error. Try to correct it.
if (!good_packet && (correct_errors_erasures((unsigned char *)p, rx_len, 0, 0) != 0)) {
// We corrected it
corrected_packet = true;
}
}
}
// Should we pull PPM data off of the head of the packet?
if ((good_packet || corrected_packet) && radio_dev->ppm_recv_mode) {
uint8_t ppm_len = RFM22B_PPM_NUM_CHANNELS + (radio_dev->ppm_only_mode ? 2 : 1);
// Ensure the packet it long enough
if (data_len < ppm_len) {
good_packet = false;
}
// Verify the CRC if this is a PPM only packet.
if ((good_packet || corrected_packet) && radio_dev->ppm_only_mode) {
uint8_t crc = 0;
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS + 1; ++i) {
crc = PIOS_CRC_updateByte(crc, p[i]);
}
if (p[RFM22B_PPM_NUM_CHANNELS + 1] != crc) {
good_packet = false;
corrected_packet = false;
}
}
if (good_packet || corrected_packet) {
for (uint8_t i = 0; i < RFM22B_PPM_NUM_CHANNELS; ++i) {
// Calculate 9-bit value taking the LSB from byte 0
uint32_t val = (p[i + 1] << 1) + ((p[0] >> i) & 1);
// Is this a valid channel?
if (val != RFM22B_PPM_INVALID) {
radio_dev->ppm[i] = (uint16_t)(RFM22B_PPM_MIN_US + (val - RFM22B_PPM_MIN) * RFM22B_PPM_SCALE);
} else {
// Set failsafe value
radio_dev->ppm[i] = PIOS_RCVR_TIMEOUT;
}
}
p += RFM22B_PPM_NUM_CHANNELS + 1;
data_len -= RFM22B_PPM_NUM_CHANNELS + 1;
// Call the PPM received callback if it's available.
if (radio_dev->ppm_callback) {
radio_dev->ppm_callback(radio_dev->ppm_context, radio_dev->ppm);
}
}
}
// Set the packet status
if (good_packet) {
rfm22b_add_rx_status(radio_dev, RADIO_GOOD_RX_PACKET);
} else if (corrected_packet) {
// We corrected the error.
rfm22b_add_rx_status(radio_dev, RADIO_CORRECTED_RX_PACKET);
} else {
// We couldn't correct the error, so drop the packet.
rfm22b_add_rx_status(radio_dev, RADIO_ERROR_RX_PACKET);
}
// Increment the packet sequence number.
radio_dev->stats.rx_seq++;
enum pios_radio_event ret_event = RADIO_EVENT_RX_COMPLETE;
if (good_packet || corrected_packet) {
// Send the data to the com port
bool rx_need_yield;
if ((data_len > 0) && !radio_dev->ppm_only_mode) {
stream_num = *p;
p++;
data_len--;
if (!stream_num) {
if (radio_dev->rx_in_cb) {
(radio_dev->rx_in_cb)(radio_dev->rx_in_context, p, data_len, NULL, &rx_need_yield);
}
} else {
if (radio_dev->aux_rx_in_cb) {
(radio_dev->aux_rx_in_cb)(radio_dev->aux_rx_in_context, p, data_len, NULL, &rx_need_yield);
}
}
}
/*
* If the packet is valid and destined for us we synchronize the clock.
*/
if (!rfm22_isCoordinator(radio_dev) &&
radio_dev->rx_destination_id == rfm22_destinationID(radio_dev)) {
rfm22_synchronizeClock(radio_dev);
}
radio_dev->stats.link_state = OPLINKSTATUS_LINKSTATE_CONNECTED;
radio_dev->last_contact = pios_rfm22_time_ms();
radio_dev->stats.rssi = radio_dev->rssi_dBm;
radio_dev->stats.afc_correction = radio_dev->afc_correction_Hz;
} else {
ret_event = RADIO_EVENT_RX_COMPLETE;
}
return ret_event;
}
/**
* Receive the packet data.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event radio_rxData(struct pios_rfm22b_dev *radio_dev)
{
enum pios_radio_event ret_event = RADIO_EVENT_NUM_EVENTS;
pios_rfm22b_int_result res = PIOS_RFM22B_ProcessRx((uint32_t)radio_dev);
switch (res) {
case PIOS_RFM22B_RX_COMPLETE:
// Receive the packet.
ret_event = radio_receivePacket(radio_dev, radio_dev->rx_packet_handle, radio_dev->rx_buffer_wr);
radio_dev->rx_buffer_wr = 0;
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D2_LED_OFF;
#endif
// Start a new transaction
radio_dev->packet_start_time = 0;
break;
case PIOS_RFM22B_INT_FAILURE:
ret_event = RADIO_EVENT_RX_MODE;
break;
default:
// do nothing.
break;
}
return ret_event;
}
/*****************************************************************************
* Link Statistics Functions
*****************************************************************************/
/**
* Calculate stats from the packet receipt, transmission statistics.
*
* @param[in] rfm22b_dev The device structure
*/
static void rfm22_updateStats(struct pios_rfm22b_dev *rfm22b_dev)
{
// Add the RX packet statistics
rfm22b_dev->stats.rx_good = 0;
rfm22b_dev->stats.rx_corrected = 0;
rfm22b_dev->stats.rx_error = 0;
rfm22b_dev->stats.rx_failure = 0;
if (!rfm22_isConnected(rfm22b_dev)) {
// Set link_quality to 0 and Rssi to noise floor if disconnected
rfm22b_dev->stats.link_quality = 0;
rfm22b_dev->stats.rssi = -127;
return;
}
// Check if connection is timed out
if (rfm22_checkTimeOut(rfm22b_dev)) {
// Set the link state to disconnected.
rfm22b_dev->stats.link_state = OPLINKSTATUS_LINKSTATE_DISCONNECTED;
}
for (uint8_t i = 0; i < RFM22B_RX_PACKET_STATS_LEN; ++i) {
uint32_t val = rfm22b_dev->rx_packet_stats[i];
for (uint8_t j = 0; j < 16; ++j) {
switch ((val >> (j * 2)) & 0x3) {
case RADIO_GOOD_RX_PACKET:
rfm22b_dev->stats.rx_good++;
break;
case RADIO_CORRECTED_RX_PACKET:
rfm22b_dev->stats.rx_corrected++;
break;
case RADIO_ERROR_RX_PACKET:
rfm22b_dev->stats.rx_error++;
break;
case RADIO_FAILURE_RX_PACKET:
rfm22b_dev->stats.rx_failure++;
break;
}
}
}
// Calculate the link quality metric, which is related to the number of good packets in relation to the number of bad packets.
// Note: This assumes that the number of packets sampled for the stats is 64.
// Using this equation, error and resent packets are counted as -2, and corrected packets are counted as -1.
// The range is 0 (all error or resent packets) to 128 (all good packets).
rfm22b_dev->stats.link_quality = 64 + rfm22b_dev->stats.rx_good - rfm22b_dev->stats.rx_error - rfm22b_dev->stats.rx_failure;
}
/**
* A timeout occured ?
*
* @param[in] rfm22b_dev The device structure
*/
static bool rfm22_checkTimeOut(struct pios_rfm22b_dev *rfm22b_dev)
{
return pios_rfm22_time_difference_ms(rfm22b_dev->last_contact, pios_rfm22_time_ms()) >= CONNECTED_TIMEOUT;
}
/**
* Add a status value to the RX packet status array.
*
* @param[in] rfm22b_dev The device structure
* @param[in] status The packet status value
*/
static void rfm22b_add_rx_status(struct pios_rfm22b_dev *rfm22b_dev, enum pios_rfm22b_rx_packet_status status)
{
// Shift the status registers
for (uint8_t i = RFM22B_RX_PACKET_STATS_LEN - 1; i > 0; --i) {
rfm22b_dev->rx_packet_stats[i] = (rfm22b_dev->rx_packet_stats[i] << 2) | (rfm22b_dev->rx_packet_stats[i - 1] >> 30);
}
rfm22b_dev->rx_packet_stats[0] = (rfm22b_dev->rx_packet_stats[0] << 2) | status;
}
/*****************************************************************************
* Connection Handling Functions
*****************************************************************************/
/**
* Are we a coordinator modem?
*
* @param[in] rfm22b_dev The device structure
*/
static bool rfm22_isCoordinator(struct pios_rfm22b_dev *rfm22b_dev)
{
return rfm22b_dev->coordinator;
}
/**
* Returns the destination ID to send packets to.
*
* @param[in] rfm22b_id The RFM22B device index.
* @return The destination ID
*/
uint32_t rfm22_destinationID(struct pios_rfm22b_dev *rfm22b_dev)
{
if (rfm22_isCoordinator(rfm22b_dev)) {
return rfm22b_dev->deviceID;
} else if (rfm22b_dev->coordinatorID) {
return rfm22b_dev->coordinatorID;
} else {
return 0xffffffff;
}
}
/*****************************************************************************
* Frequency Hopping Functions
*****************************************************************************/
/**
* Synchronize the clock after a packet receive from our coordinator on the syncronization channel.
* This function should be called when a packet is received on the synchronization channel.
*
* @param[in] rfm22b_dev The device structure
*/
static void rfm22_synchronizeClock(struct pios_rfm22b_dev *rfm22b_dev)
{
uint32_t start_time = rfm22b_dev->packet_start_time;
// This packet was transmitted on channel 0, calculate the time delta that will force us to transmit on channel 0 at the time this packet started.
uint16_t frequency_hop_cycle_time = rfm22b_dev->packet_time * rfm22b_dev->num_channels;
uint16_t time_delta = start_time % frequency_hop_cycle_time;
// Calculate the adjustment for the preamble
uint8_t offset = (uint8_t)ceil(35000.0F / data_rate[rfm22b_dev->datarate]);
rfm22b_dev->time_delta = frequency_hop_cycle_time - time_delta + offset +
rfm22b_dev->packet_time * rfm22b_dev->channel_index;
}
/**
* Return the estimated current time on the coordinator modem.
* This is the master clock used for all synchronization.
*
* @param[in] rfm22b_dev The device structure
*/
static uint32_t rfm22_coordinatorTime(struct pios_rfm22b_dev *rfm22b_dev)
{
uint32_t time = pios_rfm22_time_ms();
if (rfm22_isCoordinator(rfm22b_dev)) {
return time;
}
return time + rfm22b_dev->time_delta;
}
/**
* Return true if this modem is in the send interval, which allows the modem to initiate a transmit.
*
* @param[in] rfm22b_dev The device structure
*/
static bool rfm22_timeToSend(struct pios_rfm22b_dev *rfm22b_dev)
{
uint32_t time = rfm22_coordinatorTime(rfm22b_dev);
bool is_coordinator = rfm22_isCoordinator(rfm22b_dev);
// If this is a one-way link, only the coordinator can send.
uint8_t packet_period = rfm22b_dev->packet_time;
if (rfm22b_dev->one_way_link) {
if (is_coordinator) {
return ((time - 1) % (packet_period)) == 0;
} else {
return false;
}
}
if (!is_coordinator) {
time += packet_period - 1;
} else {
time -= 1;
}
return (time % (packet_period * 2)) == 0;
}
/**
* Calculate the nth channel index.
*
* @param[in] rfm22b_dev The device structure
* @param[in] index The channel index to calculate
*/
static uint8_t rfm22_calcChannel(struct pios_rfm22b_dev *rfm22b_dev, uint8_t index)
{
// Make sure we don't index outside of the range.
uint8_t idx = index % rfm22b_dev->num_channels;
// Are we switching to a new channel?
if ((idx != rfm22b_dev->channel_index) && !rfm22_isCoordinator(rfm22b_dev) && rfm22_checkTimeOut(rfm22b_dev)) {
// Set the link state to disconnected.
rfm22b_dev->stats.link_state = OPLINKSTATUS_LINKSTATE_DISCONNECTED;
// Update stats
rfm22_updateStats(rfm22b_dev);
// Stay on first channel.
idx = 0;
}
rfm22b_dev->channel_index = idx;
return rfm22b_dev->channels[idx];
}
/**
* Calculate what the current channel shold be.
*
* @param[in] rfm22b_dev The device structure
*/
static uint8_t rfm22_calcChannelFromClock(struct pios_rfm22b_dev *rfm22b_dev)
{
uint32_t time = rfm22_coordinatorTime(rfm22b_dev);
// Divide time into 8ms blocks. Coordinator sends in first 2 ms, and remote send in 5th and 6th ms.
// Channel changes occur in the last 2 ms.
uint8_t n = (time / rfm22b_dev->packet_time) % rfm22b_dev->num_channels;
return rfm22_calcChannel(rfm22b_dev, n);
}
/**
* Change channels to the calculated current channel.
*
* @param[in] rfm22b_dev The device structure
*/
static bool rfm22_changeChannel(struct pios_rfm22b_dev *rfm22b_dev)
{
// A disconnected non-coordinator modem should sit on the sync channel until connected.
if (!rfm22_isCoordinator(rfm22b_dev) && !rfm22_isConnected(rfm22b_dev)) {
return rfm22_setFreqHopChannel(rfm22b_dev, rfm22_calcChannel(rfm22b_dev, 0));
} else {
return rfm22_setFreqHopChannel(rfm22b_dev, rfm22_calcChannelFromClock(rfm22b_dev));
}
}
/*****************************************************************************
* Error Handling Functions
*****************************************************************************/
/**
* Recover from a transmit failure.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_txFailure(struct pios_rfm22b_dev *rfm22b_dev)
{
rfm22b_dev->stats.tx_failure++;
rfm22b_dev->packet_start_time = 0;
rfm22b_dev->tx_data_wr = rfm22b_dev->tx_data_rd = 0;
return RADIO_EVENT_TX_START;
}
/**
* Recover from a timeout event.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_timeout(struct pios_rfm22b_dev *rfm22b_dev)
{
rfm22b_dev->stats.timeouts++;
rfm22b_dev->packet_start_time = 0;
// Release the Tx packet if it's set.
if (rfm22b_dev->tx_packet_handle != 0) {
rfm22b_dev->tx_data_rd = rfm22b_dev->tx_data_wr = 0;
}
rfm22b_dev->rfm22b_state = RFM22B_STATE_TRANSITION;
rfm22b_dev->rx_buffer_wr = 0;
TX_LED_OFF;
RX_LED_OFF;
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D1_LED_OFF;
D2_LED_OFF;
D3_LED_OFF;
D4_LED_OFF;
#endif
return RADIO_EVENT_RX_MODE;
}
/**
* Recover from a severe error.
*
* @param[in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_error(struct pios_rfm22b_dev *rfm22b_dev)
{
rfm22b_dev->stats.resets++;
rfm22_clearLEDs();
return RADIO_EVENT_INITIALIZE;
}
/**
* A fatal error has occured in the state machine.
* this should not happen.
*
* @parem [in] rfm22b_dev The device structure
* @return enum pios_radio_event The next event to inject
*/
static enum pios_radio_event rfm22_fatal_error(__attribute__((unused)) struct pios_rfm22b_dev *rfm22b_dev)
{
// RF module error .. flash the LED's
rfm22_clearLEDs();
for (unsigned int j = 0; j < 16; j++) {
USB_LED_ON;
LINK_LED_ON;
RX_LED_OFF;
TX_LED_OFF;
PIOS_DELAY_WaitmS(200);
USB_LED_OFF;
LINK_LED_OFF;
RX_LED_ON;
TX_LED_ON;
PIOS_DELAY_WaitmS(200);
}
PIOS_DELAY_WaitmS(1000);
PIOS_Assert(0);
return RADIO_EVENT_FATAL_ERROR;
}
/*****************************************************************************
* Utility Functions
*****************************************************************************/
/**
* Get the current time in ms from the ticks counter.
*/
static uint32_t pios_rfm22_time_ms()
{
return xTaskGetTickCount() * portTICK_RATE_MS;
}
/**
* Calculate the time difference between the start time and end time.
* Times are in ms. Also handles rollover.
*
* @param[in] start_time The start time in ms.
* @param[in] end_time The end time in ms.
*/
static uint32_t pios_rfm22_time_difference_ms(uint32_t start_time, uint32_t end_time)
{
if (end_time >= start_time) {
return end_time - start_time;
}
// Rollover
return (UINT32_MAX - start_time) + end_time;
}
/**
* Allocate the device structure
*/
#if defined(PIOS_INCLUDE_FREERTOS)
static struct pios_rfm22b_dev *pios_rfm22_alloc(void)
{
struct pios_rfm22b_dev *rfm22b_dev;
rfm22b_dev = (struct pios_rfm22b_dev *)pios_malloc(sizeof(*rfm22b_dev));
if (!rfm22b_dev) {
return NULL;
}
memset(rfm22b_dev, 0, sizeof(*rfm22b_dev));
rfm22b_dev->magic = PIOS_RFM22B_DEV_MAGIC;
return rfm22b_dev;
}
#else
static struct pios_rfm22b_dev pios_rfm22b_devs[PIOS_RFM22B_MAX_DEVS];
static uint8_t pios_rfm22b_num_devs;
static struct pios_rfm22b_dev *pios_rfm22_alloc(void)
{
struct pios_rfm22b_dev *rfm22b_dev;
if (pios_rfm22b_num_devs >= PIOS_RFM22B_MAX_DEVS) {
return NULL;
}
rfm22b_dev = &pios_rfm22b_devs[pios_rfm22b_num_devs++];
memset(rfm22b_dev, 0, sizeof(*rfm22b_dev));
rfm22b_dev->magic = PIOS_RFM22B_DEV_MAGIC;
return rfm22b_dev;
}
#endif /* if defined(PIOS_INCLUDE_FREERTOS) */
/**
* Turn off all of the LEDs
*/
static void rfm22_clearLEDs(void)
{
LINK_LED_OFF;
RX_LED_OFF;
TX_LED_OFF;
#ifdef PIOS_RFM22B_DEBUG_ON_TELEM
D1_LED_OFF;
D2_LED_OFF;
D3_LED_OFF;
D4_LED_OFF;
#endif
}
/*****************************************************************************
* SPI Read/Write Functions
*****************************************************************************/
/**
* Assert the chip select line.
*
* @param[in] rfm22b_dev The RFM22B device.
*/
static void rfm22_assertCs(struct pios_rfm22b_dev *rfm22b_dev)
{
PIOS_DELAY_WaituS(1);
if (rfm22b_dev->spi_id != 0) {
PIOS_SPI_RC_PinSet(rfm22b_dev->spi_id, rfm22b_dev->slave_num, 0);
}
}
/**
* Deassert the chip select line.
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
*/
static void rfm22_deassertCs(struct pios_rfm22b_dev *rfm22b_dev)
{
if (rfm22b_dev->spi_id != 0) {
PIOS_SPI_RC_PinSet(rfm22b_dev->spi_id, rfm22b_dev->slave_num, 1);
}
}
/**
* Claim the SPI bus.
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
*/
static void rfm22_claimBus(struct pios_rfm22b_dev *rfm22b_dev)
{
if (rfm22b_dev->spi_id != 0) {
PIOS_SPI_ClaimBus(rfm22b_dev->spi_id);
}
}
/**
* Release the SPI bus.
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
*/
static void rfm22_releaseBus(struct pios_rfm22b_dev *rfm22b_dev)
{
if (rfm22b_dev->spi_id != 0) {
PIOS_SPI_ReleaseBus(rfm22b_dev->spi_id);
}
}
/**
* Claim the semaphore and write a byte to a register
*
* @param[in] rfm22b_dev The RFM22B device.
* @param[in] addr The address to write to
* @param[in] data The datat to write to that address
*/
static void rfm22_write_claim(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr, uint8_t data)
{
rfm22_claimBus(rfm22b_dev);
rfm22_assertCs(rfm22b_dev);
uint8_t buf[2] = { addr | 0x80, data };
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, buf, NULL, sizeof(buf), NULL);
rfm22_deassertCs(rfm22b_dev);
rfm22_releaseBus(rfm22b_dev);
}
/**
* Write a byte to a register without claiming the semaphore
*
* @param[in] rfm22b_dev The RFM22B device.
* @param[in] addr The address to write to
* @param[in] data The datat to write to that address
*/
static void rfm22_write(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr, uint8_t data)
{
rfm22_assertCs(rfm22b_dev);
uint8_t buf[2] = { addr | 0x80, data };
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, buf, NULL, sizeof(buf), NULL);
rfm22_deassertCs(rfm22b_dev);
}
/**
* Read a byte from an RFM22b register without claiming the bus
*
* @param[in] rfm22b_dev The RFM22B device structure pointer.
* @param[in] addr The address to read from
* @return Returns the result of the register read
*/
static uint8_t rfm22_read(struct pios_rfm22b_dev *rfm22b_dev, uint8_t addr)
{
uint8_t out[2] = { addr &0x7F, 0xFF };
uint8_t in[2];
rfm22_assertCs(rfm22b_dev);
PIOS_SPI_TransferBlock(rfm22b_dev->spi_id, out, in, sizeof(out), NULL);
rfm22_deassertCs(rfm22b_dev);
return in[1];
}
static void rfm22_hmac_sha1(const uint8_t *data, size_t len,
uint8_t key[SHA1_DIGEST_LENGTH],
uint8_t digest[SHA1_DIGEST_LENGTH])
{
uint8_t ipad[64] = { 0 };
uint8_t opad[64] = { 0 };
static SHA1_CTX *ctx;
ctx = pios_malloc(sizeof(SHA1_CTX));
memcpy(ipad, key, SHA1_DIGEST_LENGTH);
memcpy(opad, key, SHA1_DIGEST_LENGTH);
for (int i = 0; i < 64; i++) {
ipad[i] ^= 0x36;
opad[i] ^= 0x5c;
}
SHA1Init(ctx);
SHA1Update(ctx, ipad, sizeof(ipad));
SHA1Update(ctx, data, len);
SHA1Final(digest, ctx);
SHA1Init(ctx);
SHA1Update(ctx, opad, sizeof(opad));
SHA1Update(ctx, digest, SHA1_DIGEST_LENGTH);
SHA1Final(digest, ctx);
pios_free(ctx);
}
static bool rfm22_gen_channels(uint32_t coordid, enum rfm22b_datarate rate, uint8_t min,
uint8_t max, uint8_t channels[MAX_CHANNELS], uint8_t *clen)
{
uint32_t data = 0;
uint8_t cpos = 0;
uint8_t chan_range = (max / channel_spacing[rate] - min / channel_spacing[rate]) + 1;
uint8_t key[SHA1_DIGEST_LENGTH] = { 0 };
uint8_t digest[SHA1_DIGEST_LENGTH];
uint8_t *all_channels;
all_channels = pios_malloc(RFM22B_NUM_CHANNELS);
memcpy(key, &coordid, sizeof(coordid));
for (int i = 0; i < chan_range; i++) {
all_channels[i] = min / channel_spacing[rate] + i;
}
int j = SHA1_DIGEST_LENGTH;
for (int i = 0; i < chan_range && i < MAX_CHANNELS; i++) {
uint8_t rnd;
uint8_t r;
uint8_t tmp;
if (j == SHA1_DIGEST_LENGTH) {
rfm22_hmac_sha1((uint8_t *)&data, sizeof(data), key, digest);
j = 0;
data++;
}
rnd = digest[j];
j++;
r = rnd % (chan_range - i) + i;
tmp = all_channels[i];
all_channels[i] = all_channels[r];
all_channels[r] = tmp;
}
for (int i = 0; i < chan_range && cpos < MAX_CHANNELS; i++, cpos++) {
channels[cpos] = all_channels[i] * channel_spacing[rate];
}
*clen = cpos & 0xfe;
pios_free(all_channels);
return *clen > 0;
}
#endif /* PIOS_INCLUDE_RFM22B */
/**
* @}
* @}
*/