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LibrePilot/flight/PiOS/STM32F10x/pios_spektrum.c
2011-09-06 16:23:11 -05:00

351 lines
9.3 KiB
C

/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_SPEKTRUM Spektrum receiver functions
* @brief Code to read Spektrum input
* @{
*
* @file pios_spektrum.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief USART commands. Inits USARTs, controls USARTs & Interrupt handlers. (STM32 dependent)
* @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
*/
/* Project Includes */
#include "pios.h"
#if defined(PIOS_INCLUDE_SPEKTRUM)
#include "pios_spektrum_priv.h"
/**
* @Note Framesyncing:
* The code resets the watchdog timer whenever a single byte is received, so what watchdog code
* is never called if regularly getting bytes.
* RTC timer is running @625Hz, supervisor timer has divider 5 so frame sync comes every 1/125Hz=8ms.
* Good for both 11ms and 22ms framecycles
*/
/* Global Variables */
/* Provide a RCVR driver */
static int32_t PIOS_SPEKTRUM_Get(uint32_t rcvr_id, uint8_t channel);
const struct pios_rcvr_driver pios_spektrum_rcvr_driver = {
.read = PIOS_SPEKTRUM_Get,
};
enum pios_spektrum_dev_magic {
PIOS_SPEKTRUM_DEV_MAGIC = 0xa9b9c9d9,
};
struct pios_spektrum_fsm {
uint16_t channel;
uint16_t CaptureValue[PIOS_SPEKTRUM_NUM_INPUTS];
uint16_t CaptureValueTemp[PIOS_SPEKTRUM_NUM_INPUTS];
uint8_t prev_byte;
uint8_t sync;
uint8_t bytecount;
uint8_t datalength;
uint8_t frame_error;
uint8_t sync_of;
};
struct pios_spektrum_dev {
enum pios_spektrum_dev_magic magic;
const struct pios_spektrum_cfg * cfg;
struct pios_spektrum_fsm fsm;
uint16_t supv_timer;
};
static bool PIOS_SPEKTRUM_validate(struct pios_spektrum_dev * spektrum_dev)
{
return (spektrum_dev->magic == PIOS_SPEKTRUM_DEV_MAGIC);
}
#if defined(PIOS_INCLUDE_FREERTOS)
static struct pios_spektrum_dev * PIOS_SPEKTRUM_alloc(void)
{
struct pios_spektrum_dev * spektrum_dev;
spektrum_dev = (struct pios_spektrum_dev *)pvPortMalloc(sizeof(*spektrum_dev));
if (!spektrum_dev) return(NULL);
spektrum_dev->magic = PIOS_SPEKTRUM_DEV_MAGIC;
return(spektrum_dev);
}
#else
static struct pios_spektrum_dev pios_spektrum_devs[PIOS_SPEKTRUM_MAX_DEVS];
static uint8_t pios_spektrum_num_devs;
static struct pios_spektrum_dev * PIOS_SPEKTRUM_alloc(void)
{
struct pios_spektrum_dev * spektrum_dev;
if (pios_spektrum_num_devs >= PIOS_SPEKTRUM_MAX_DEVS) {
return (NULL);
}
spektrum_dev = &pios_spektrum_devs[pios_spektrum_num_devs++];
spektrum_dev->magic = PIOS_SPEKTRUM_DEV_MAGIC;
return (spektrum_dev);
}
#endif
static void PIOS_SPEKTRUM_Supervisor(uint32_t spektrum_id);
static bool PIOS_SPEKTRUM_Bind(const struct pios_spektrum_cfg * cfg, uint8_t bind);
static int32_t PIOS_SPEKTRUM_UpdateFSM(struct pios_spektrum_fsm * fsm, uint8_t b);
static uint16_t PIOS_SPEKTRUM_RxInCallback(uint32_t context, uint8_t * buf, uint16_t buf_len, uint16_t * headroom, bool * need_yield)
{
struct pios_spektrum_dev * spektrum_dev = (struct pios_spektrum_dev *)context;
bool valid = PIOS_SPEKTRUM_validate(spektrum_dev);
PIOS_Assert(valid);
/* process byte(s) and clear receive timer */
for (uint8_t i = 0; i < buf_len; i++) {
PIOS_SPEKTRUM_UpdateFSM(&(spektrum_dev->fsm), buf[i]);
spektrum_dev->supv_timer = 0;
}
/* Always signal that we can accept another byte */
if (headroom) {
*headroom = 1;
}
/* We never need a yield */
*need_yield = false;
/* Always indicate that all bytes were consumed */
return (buf_len);
}
static void PIOS_SPEKTRUM_ResetFSM(struct pios_spektrum_fsm * fsm)
{
fsm->channel = 0;
fsm->prev_byte = 0xFF;
fsm->sync = 0;
fsm->bytecount = 0;
fsm->datalength = 0;
fsm->frame_error = 0;
fsm->sync_of = 0;
}
/**
* Decodes a byte
* \param[in] b byte which should be spektrum decoded
* \return 0 if no error
* \return -1 if USART not available
* \return -2 if buffer full (retry)
*/
static int32_t PIOS_SPEKTRUM_UpdateFSM(struct pios_spektrum_fsm * fsm, uint8_t b)
{
fsm->bytecount++;
if (fsm->sync == 0) {
/* Known sync bytes, 0x01, 0x02, 0x12, 0xb2 */
/* 0xb2 DX8 3bind pulses only */
if (fsm->bytecount == 2) {
if ((b == 0x01) || (b == 0x02) || (b == 0xb2)) {
fsm->datalength=0; // 10bit
fsm->sync = 1;
fsm->bytecount = 2;
}
else if(b == 0x12) {
fsm->datalength=1; // 11bit
fsm->sync = 1;
fsm->bytecount = 2;
}
else
{
fsm->bytecount = 0;
}
}
} else {
if ((fsm->bytecount % 2) == 0) {
uint16_t data;
uint8_t channeln;
fsm->channel = (fsm->prev_byte << 8) + b;
channeln = (fsm->channel >> (10+fsm->datalength)) & 0x0F;
data = fsm->channel & (0x03FF+(0x0400*fsm->datalength));
if(channeln==0 && data<10) // discard frame if throttle misbehaves
{
fsm->frame_error=1;
}
if (channeln < PIOS_SPEKTRUM_NUM_INPUTS && !fsm->frame_error)
fsm->CaptureValueTemp[channeln] = data;
}
}
if (fsm->bytecount == 16) {
fsm->bytecount = 0;
fsm->sync = 0;
fsm->sync_of = 0;
if (!fsm->frame_error)
{
for(int i=0;i<PIOS_SPEKTRUM_NUM_INPUTS;i++)
{
fsm->CaptureValue[i] = fsm->CaptureValueTemp[i];
}
}
fsm->frame_error=0;
}
fsm->prev_byte = b;
return 0;
}
/**
* Bind and Initialise Spektrum satellite receiver
*/
int32_t PIOS_SPEKTRUM_Init(uint32_t * spektrum_id, const struct pios_spektrum_cfg *cfg, const struct pios_com_driver * driver, uint32_t lower_id, uint8_t bind)
{
PIOS_DEBUG_Assert(spektrum_id);
PIOS_DEBUG_Assert(cfg);
PIOS_DEBUG_Assert(driver);
struct pios_spektrum_dev * spektrum_dev;
spektrum_dev = (struct pios_spektrum_dev *) PIOS_SPEKTRUM_alloc();
if (!spektrum_dev) goto out_fail;
/* Bind the configuration to the device instance */
spektrum_dev->cfg = cfg;
if (bind) {
PIOS_SPEKTRUM_Bind(cfg,bind);
}
PIOS_SPEKTRUM_ResetFSM(&(spektrum_dev->fsm));
*spektrum_id = (uint32_t)spektrum_dev;
(driver->bind_rx_cb)(lower_id, PIOS_SPEKTRUM_RxInCallback, *spektrum_id);
if (!PIOS_RTC_RegisterTickCallback(PIOS_SPEKTRUM_Supervisor, *spektrum_id)) {
PIOS_DEBUG_Assert(0);
}
return (0);
out_fail:
return(-1);
}
/**
* Get the value of an input channel
* \param[in] Channel Number of the channel desired
* \output -1 Channel not available
* \output >0 Channel value
*/
static int32_t PIOS_SPEKTRUM_Get(uint32_t rcvr_id, uint8_t channel)
{
struct pios_spektrum_dev * spektrum_dev = (struct pios_spektrum_dev *)rcvr_id;
if(!PIOS_SPEKTRUM_validate(spektrum_dev))
return PIOS_RCVR_INVALID;
/* Return error if channel not available */
if (channel >= PIOS_SPEKTRUM_NUM_INPUTS) {
return PIOS_RCVR_INVALID;
}
return spektrum_dev->fsm.CaptureValue[channel];
}
/**
* Spektrum bind function
* \output true Successful bind
* \output false Bind failed
*/
static bool PIOS_SPEKTRUM_Bind(const struct pios_spektrum_cfg * cfg, uint8_t bind)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = cfg->bind.init.GPIO_Pin;
GPIO_InitStructure.GPIO_Speed = cfg->bind.init.GPIO_Speed;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
/* just to limit bind pulses */
bind=(bind<=10)?bind:10;
GPIO_Init(cfg->bind.gpio, &cfg->bind.init);
/* RX line, set high */
GPIO_SetBits(cfg->bind.gpio, cfg->bind.init.GPIO_Pin);
/* on CC works upto 140ms, I guess bind window is around 20-140ms after powerup */
PIOS_DELAY_WaitmS(60);
for (int i = 0; i < bind ; i++) {
/* RX line, drive low for 120us */
GPIO_ResetBits(cfg->bind.gpio, cfg->bind.init.GPIO_Pin);
PIOS_DELAY_WaituS(120);
/* RX line, drive high for 120us */
GPIO_SetBits(cfg->bind.gpio, cfg->bind.init.GPIO_Pin);
PIOS_DELAY_WaituS(120);
}
/* RX line, set input and wait for data, PIOS_SPEKTRUM_Init */
GPIO_Init(cfg->bind.gpio, &GPIO_InitStructure);
return true;
}
/**
*@brief This function is called between frames and when a spektrum word hasnt been decoded for too long
*@brief clears the channel values
*/
static void PIOS_SPEKTRUM_Supervisor(uint32_t spektrum_id)
{
struct pios_spektrum_dev * spektrum_dev = (struct pios_spektrum_dev *)spektrum_id;
bool valid = PIOS_SPEKTRUM_validate(spektrum_dev);
PIOS_Assert(valid);
/* 625hz */
spektrum_dev->supv_timer++;
if(spektrum_dev->supv_timer > 4) {
/* sync between frames */
struct pios_spektrum_fsm * fsm = &(spektrum_dev->fsm);
fsm->sync = 0;
fsm->bytecount = 0;
fsm->prev_byte = 0xFF;
fsm->frame_error = 0;
fsm->sync_of++;
/* watchdog activated after 200ms silence */
if (fsm->sync_of > 30) {
/* signal lost */
fsm->sync_of = 0;
for (int i = 0; i < PIOS_SPEKTRUM_NUM_INPUTS; i++) {
fsm->CaptureValue[i] = PIOS_RCVR_TIMEOUT;
fsm->CaptureValueTemp[i] = PIOS_RCVR_TIMEOUT;
}
}
spektrum_dev->supv_timer = 0;
}
}
#endif
/**
* @}
* @}
*/