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OP-21 Flight/Bootloader - experimental modules implementing a simple serial packet (SSP) protocol. ssp_test is a test framework. ssp is the module, main_ssp.c prototype module on how this could be used in the bootloader, it is not fully functional, additional logic required for start-up detection to decide if serial initialization is required.

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git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@1909 ebee16cc-31ac-478f-84a7-5cbb03baadba
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kokomojoe 2010-10-07 04:59:18 +00:00 committed by kokomojoe
parent 5c9b09a72d
commit a0b3b47c48
4 changed files with 1465 additions and 0 deletions
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121
flight/Bootloaders/OpenPilot/inc/ssp.h Normal file
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/*******************************************************************
*
* NAME: ssp.h
*
*
*******************************************************************/
#ifndef SSP_H
#define SSP_H
/** INCLUDE FILES **/
#include <stdint.h>
/** LOCAL DEFINITIONS **/
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#define SSP_TX_IDLE 0 // not expecting a ACK packet (no current transmissions in progress)
#define SSP_TX_WAITING 1 // waiting for a valid ACK to arrive
#define SSP_TX_TIMEOUT 2 // failed to receive a valid ACK in the timeout period, after retrying.
#define SSP_TX_ACKED 3 // valid ACK received before timeout period.
#define SSP_TX_BUFOVERRUN 4 // amount of data to send execeds the transmission buffer sizeof
#define SSP_TX_BUSY 5 // Attempted to start a transmission while a transmission was already in progress.
//#define SSP_TX_FAIL - failure...
#define SSP_RX_IDLE 0
#define SSP_RX_RECEIVING 1
#define SSP_RX_COMPLETE 2
// types of packet that can be received
#define SSP_RX_DATA 5
#define SSP_RX_ACK 6
#define SSP_RX_SYNCH 7
typedef enum decodeState_ {
decode_len1_e = 0,
decode_seqNo_e,
decode_data_e,
decode_crc1_e,
decode_crc2_e,
decode_idle_e
} DecodeState_t;
typedef enum ReceiveState {
state_escaped_e = 0,
state_unescaped_e
} ReceiveState_t;
typedef struct
{
uint8_t *pbuff;
uint16_t length;
uint16_t crc;
uint8_t seqNo;
} Packet_t;
typedef struct {
uint8_t *rxBuf; // Buffer used to store rcv data
uint16_t rxBufSize; // rcv buffer size.
uint8_t *txBuf; // Length of data in buffer
uint16_t txBufSize; // CRC for data in Packet buff
uint16_t max_retry; // Maximum number of retrys for a single transmit.
int32_t timeoutLen; // how long to wait for each retry to succeed
void (*pfCallBack)( uint8_t *, uint16_t); // call back function that is called when a full packet has been received
int16_t (*pfSerialRead)(void); // function to call to read a byte from serial hardware
void (*pfSerialWrite)( uint8_t ); // function used to write a byte to serial hardware for transmission
uint32_t (*pfGetTime)(void); // function returns time in number of seconds that has elapsed from a given reference point
} PortConfig_t;
typedef struct Port_tag {
void (*pfCallBack)( uint8_t *, uint16_t); // call back function that is called when a full packet has been received
int16_t (*pfSerialRead)(void); // function to read a character from the serial input stream
void (*pfSerialWrite)( uint8_t ); // function to write a byte to be sent out the serial port
uint32_t (*pfGetTime)(void); // function returns time in number of seconds that has elapsed from a given reference point
uint8_t retryCount; // how many times have we tried to transmit the 'send' packet
uint8_t maxRetryCount; // max. times to try to transmit the 'send' packet
int32_t timeoutLen; // how long to wait for each retry to succeed
int32_t timeout; // current timeout. when 'time' reaches this point we have timed out
uint8_t txSeqNo; // current 'send' packet sequence number
uint16_t rxBufPos; // current buffer position in the receive packet
uint16_t rxBufLen; // number of 'data' bytes in the buffer
uint8_t rxSeqNo; // current 'receive' packet number
uint16_t rxBufSize; // size of the receive buffer.
uint16_t txBufSize; // size of the transmit buffer.
uint8_t *txBuf; // transmit buffer. REquired to store a copy of packet data in case a retry is needed.
uint8_t *rxBuf; // receive buffer. Used to store data as a packet is received.
uint16_t sendSynch; // flag to indicate that we should send a synchronize packet to the host
// this is required when switching from the application to the bootloader
// and vice-versa. This fixes the firwmare download timeout.
// when this flag is set to true, the next time we send a packet we will first
// send a synchronize packet.
ReceiveState_t InputState;
DecodeState_t DecodeState;
uint16_t SendState;
uint16_t crc;
uint32_t RxError;
uint32_t TxError;
uint16_t flags;
} Port_t;
/** Public Data **/
/** PUBLIC FUNCTIONS **/
int16_t ssp_ReceiveProcess( Port_t *thisport );
int16_t ssp_SendProcess( Port_t *thisport );
uint16_t ssp_SendString( Port_t *thisport, char *str );
int16_t ssp_SendData(Port_t *thisport, const uint8_t * data,const uint16_t length );
void ssp_Init( Port_t *thisport, const PortConfig_t* const info);
int16_t ssp_ReceiveByte(Port_t *thisport );
uint16_t ssp_Synchronise( Port_t *thisport );
/** EXTERNAL FUNCTIONS **/
#endif

300
flight/Bootloaders/OpenPilot/main_ssp.c Normal file
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/**
******************************************************************************
* @addtogroup OpenPilotSystem OpenPilot System
* @brief These files are the core system files of OpenPilot.
* They are the ground layer just above PiOS. In practice, OpenPilot actually starts
* in the main() function of openpilot.c
* @{
* @addtogroup OpenPilotCore OpenPilot Core
* @brief This is where the OP firmware starts. Those files also define the compile-time
* options of the firmware.
* @{
* @file openpilot.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Sets up and runs main OpenPilot tasks.
* @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
*/
/* OpenPilot Includes */
//#include "openpilot.h"
#include <pios.h>
#include "pios_opahrs.h"
#include "stopwatch.h"
#include "op_dfu.h"
#include "usb_lib.h"
/* Prototype of PIOS_Board_Init() function */
extern void PIOS_Board_Init(void);
extern void FLASH_Download();
#define BSL_HOLD_STATE ((PIOS_USB_DETECT_GPIO_PORT->IDR & PIOS_USB_DETECT_GPIO_PIN) ? 0 : 1)
/* Private typedef -----------------------------------------------------------*/
typedef void (*pFunction)(void);
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
pFunction Jump_To_Application;
uint32_t JumpAddress;
/// LEDs PWM
uint32_t period1 = 50; // *100 uS -> 5 mS
uint32_t sweep_steps1 = 100; // * 5 mS -> 500 mS
uint32_t period2 = 50; // *100 uS -> 5 mS
uint32_t sweep_steps2 = 100; // * 5 mS -> 500 mS
/* Extern variables ----------------------------------------------------------*/
DFUStates DeviceState;
uint8_t JumpToApp = FALSE;
uint8_t GO_dfu = FALSE;
uint8_t USB_connected = FALSE;
uint8_t User_DFU_request = FALSE;
static uint8_t mReceive_Buffer[64];
uint8_t comm_port;
/* Private function prototypes -----------------------------------------------*/
uint32_t LedPWM(uint32_t pwm_period, uint32_t pwm_sweep_steps, uint32_t count);
uint8_t processRX();
void jump_to_app();
#define BLUE LED1
#define RED LED2
int main() {
/* NOTE: Do NOT modify the following start-up sequence */
/* Any new initialization functions should be added in OpenPilotInit() */
/* Brings up System using CMSIS functions, enables the LEDs. */
PIOS_SYS_Init();
if (BSL_HOLD_STATE == 0)
USB_connected = TRUE;
if( USB_connected == TRUE ) {
comm_port = PIOS_COM_TELEM_USB;
} else {
// check for user request to enter bootloader
// if true then:
// if( check_user_request() == TRUE ) {
// USER_DFU_request = TRUE;
// comm_port = PIOS_COM_TELEM_RF;
// ssp_Init( rf_port, rf_port_config );
// }
}
if ((USB_connected==TRUE) || (User_DFU_request==TRUE)) {
GO_dfu = TRUE;
PIOS_Board_Init();
PIOS_OPAHRS_Init();
DeviceState = BLidle;
STOPWATCH_Init(100);
USB_connected = TRUE;
PIOS_SPI_RC_PinSet(PIOS_OPAHRS_SPI, 0);
//OPDfuIni(false);
} else {
JumpToApp = TRUE;
}
STOPWATCH_Reset();
while (TRUE) {
if (JumpToApp == TRUE) {
jump_to_app();
}
flash_led();
if (STOPWATCH_ValueGet() > 100 * 50 * 100)
STOPWATCH_Reset();
if ((STOPWATCH_ValueGet() > 60000) && (DeviceState == BLidle))
JumpToApp = TRUE;
//processRX();
processComm();
DataDownload(start);
//DelayWithDown(10);//1000000);
}
}
void jump_to_app() {
if (((*(__IO uint32_t*) START_OF_USER_CODE) & 0x2FFE0000) == 0x20000000) { /* Jump to user application */
FLASH_Lock();
RCC_APB2PeriphResetCmd(0xffffffff, ENABLE);
RCC_APB1PeriphResetCmd(0xffffffff, ENABLE);
RCC_APB2PeriphResetCmd(0xffffffff, DISABLE);
RCC_APB1PeriphResetCmd(0xffffffff, DISABLE);
_SetCNTR(0); // clear interrupt mask
_SetISTR(0); // clear all requests
JumpAddress = *(__IO uint32_t*) (START_OF_USER_CODE + 4);
Jump_To_Application = (pFunction) JumpAddress;
/* Initialize user application's Stack Pointer */
__set_MSP(*(__IO uint32_t*) START_OF_USER_CODE);
Jump_To_Application();
} else {
DeviceState = failed_jump;
return;
}
}
uint32_t LedPWM(uint32_t pwm_period, uint32_t pwm_sweep_steps, uint32_t count) {
uint32_t pwm_duty = ((count / pwm_period) % pwm_sweep_steps)
/ (pwm_sweep_steps / pwm_period);
if ((count % (2 * pwm_period * pwm_sweep_steps)) > pwm_period
* pwm_sweep_steps)
pwm_duty = pwm_period - pwm_duty; // negative direction each 50*100 ticks
return ((count % pwm_period) > pwm_duty) ? 1 : 0;
}
uint8_t processRX() {
while(PIOS_COM_ReceiveBufferUsed(PIOS_COM_TELEM_USB)>=63)
{
for (int32_t x = 0; x < 63; ++x) {
mReceive_Buffer[x] = PIOS_COM_ReceiveBuffer(PIOS_COM_TELEM_USB);
}
//PIOS_IRQ_Enable();
processComand(mReceive_Buffer);
}
return TRUE;
}
#define PACKET_SIZE 64
uint8_t packet_available = false;
uint8_t data_buffer[PACKET_SIZE];
// this function is called from the serial transport layer receive state machine when a valid
// data packet is received.
void PacketCallback(uint8_t *buf, uint16_t length )
{
uint16_t x;
for( x = 0; x < length; x++ ) {
data_buffer[x] = buf[x];
}
if( packet_available == true ) {
// overrun condition...
// TODO act on overrun condition
} else {
packet_available = true;
}
}
void processComm(void)
{
uint16_t x = 0;
if (comm_port == PIOS_COM_TELEM_RF ) {
ssp_ReceiveProcess(); // pump the receive state machine
ssp_SendProcess(); // pump the transmit state machine.
// check to see if any data is available. this is updated in the callback function from the receive state machine.
if( packet_available == true ) {
// reset packet_available to let the call back function know that the packet data has been copied
// from the buffer. this will allow an overrun condition to be detected.
// also note that the only way the receive buffer is modified is through the ssp_ReceiveBuffer() function,
// otherwise data is buffered at the PIOS_COM layer.
}
} else {
if( PIOS_COM_ReceiveBufferUsed( PIOS_COM_TELEM_USB ) >= 63 ) {
for( x = 0; x < 63; x++ ) {
data_buffer[x] = PIOS_COM_Receivebuffer(PIOS_COM_TELEM_USB);
}
packet_available = true;
}
}
if( packet_available == true) {
processCommand( data_buffer);
packet_available = false;
}
}
// an alternate processComm func if both USB and serial used the same transport layer
void alt_ProcessComm(void)
{
ssp_ReceiveProcess(port);
ssp_SendProcess(port);
if( packet_available == true) {
packet_available = false;
processComand(data_buffer);
}
}
// sends out data...
uint16_t SendBuffer( uint8_t buf, uint16_t length )
{
if( comm_port == PIOS_COM_TELEM_RF ) {
ssp_SendData( rf_port, buf, length );
// or ssp_SendDataBlock( rf_port, buf, length );
} else {
PIOS_COM_BufferPut( PIOS_COM_TELEM_USB, buf, length );
}
}
void flash_led(void)
{
switch (DeviceState) {
case Last_operation_Success:
case uploadingStarting:
case DFUidle:
period1 = 50;
sweep_steps1 = 100;
PIOS_LED_Off(RED);
period2 = 0;
break;
case uploading:
period1 = 50;
sweep_steps1 = 100;
period2 = 25;
sweep_steps2 = 50;
break;
case downloading:
period1 = 25;
sweep_steps1 = 50;
PIOS_LED_Off(RED);
period2 = 0;
break;
case BLidle:
period1 = 0;
PIOS_LED_On(BLUE);
period2 = 0;
break;
default://error
period1 = 50;
sweep_steps1 = 100;
period2 = 50;
sweep_steps2 = 100;
}
if (period1 != 0) {
if (LedPWM(period1, sweep_steps1, STOPWATCH_ValueGet())) {
PIOS_LED_On(BLUE);
} else {
PIOS_LED_Off(BLUE);
}
} else {
PIOS_LED_On(BLUE);
}
if (period2 != 0) {
if (LedPWM(period2, sweep_steps2, STOPWATCH_ValueGet())) {
PIOS_LED_On(RED);
} else {
PIOS_LED_Off(RED);
}
} else {
PIOS_LED_Off(RED);
}
}

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flight/Bootloaders/OpenPilot/ssp.c Normal file
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/***********************************************************************************************************
*
* NAME: ssp.c
* DESCRIPTION: simple serial protocol - packet based serial transport layer.
* AUTHOR: Joe Hlebasko
* HISTORY: Created 1/1/2010
*
* Packet Formats
* Format:
* +------+----+------+---------------------------+--------+
* | 225 | L1 | S# | App Data (0-254 bytes) | CRC 16 |
* +------+----+------+---------------------------+--------+
*
* 225 = sync byte, indicates start of a packet
* L1 = 1 byte for size of data payload. (sequence number is part of data payload.)
* S# = 1 byte for sequence number.
* Seq of 0 = seq # synchronise request, forces other end to reset receive sequence number to 1.
* sender of synchronise request will reset the tx seq number to 1
* Seq # of 1..127 = normal data packets. Sequence number is incremented by for each transmitted
* packet. Rolls over from 127 to 1.
* if most sig. bit is set then the packet is an ACK packet of data packet sequence number of the
* lower 7 bits (1..127)
* App Data may contain 0..254 bytes. The sequence number is consider part of the payload.
* CRC 16 - 16 bits of CRC values of Sequence # and data bytes.
*
* Protocol has two types of packets: data and ack packets. ACK packets have the most sig. bit set in the
* sequence number, this implies that valid sequence numbers are 1..127
*
* This protocol uses the concept of sequences numbers to determine if a given packet has been received. This
* requires both devices to be able to synchronize sequence numbers. This is accomplished by sending a packet
* length 1 and sequence number = 0. The receive then resets it's transmit sequence number to 1.
*
* ACTIVE_SYNCH is a version that will automatically send a synch request if it receives a synch packet. Only
* one device in the communication should do otherwise you end up with an endless loops of synchronization.
* Right now each side needs to manually issues a synch request.
*
* This protocol is best used in cases where one device is the master and the other is the slave, or a don't
* speak unless spoken to type of approach.
*
* The following are items are required to initialize a port for communications:
* 1. The number attempts for each packet
* 2. time to wait for an ack.
* 3. pointer to buffer to be used for receiving.
* 4. pointer to a buffer to be used for transmission
* 5. length of each buffer (rx and tx)
* 6. Four functions:
* 1. write byte = writes a byte out the serial port (or other comm device)
* 2. read byte = retrieves a byte from the serial port. Returns -1 if a byte is not available
* 3. callback = function to call when a valid data packet has been received. This function is responsible
* to do what needs to be done with the data when it is received. The primary mission of this function
* should be to copy the data to a private buffer out of the working receive buffer to prevent overrun.
* processing should be kept to a minimum.
* 4. get time = function should return the current time. Note that time units are not specified it just
* needs to be some measure of time that increments as time passes by. The timeout values for a given
* port should the units used/returned by the get time function.
*
* All of the state information of a communication port is contained in a Port_t structure. This allows this
* module to operature on multiple communication ports with a single code base.
*
* The ssp_ReceiveProcess and ssp_SendProcess functions need to be called to process data through the
* respective state machines. Typical implementation would have a serial ISR to pull bytes out of the UART
* and place into a circular buffer. The serial read function would then pull bytes out this buffer
* processing. The TX side has the write function placing bytes into a circular buffer with the TX ISR
* pulling bytes out of the buffer and putting into the UART. It is possible to run the receive process from
* the receive ISR but care must be taken on processing data when it is received to avoid holding up the ISR
* and sending ACK packets from the receive ISR.
*
***********************************************************************************************************/
/** INCLUDE FILES **/
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include "ssp.h"
/** PRIVATE DEFINITIONS **/
#define SYNC 225 // Sync character used in Serial Protocol
#define ESC 224 // ESC character used in Serial Protocol
#define ESC_SYNC 1 // ESC_SYNC character used in Serial Protocol
#define ACK_BIT 0x80 // Ack bit, bit 7 of sequence number, 1 = Acknowledge, 0 =
// new packet
// packet location definitions.
#define LENGTH 0
#define SEQNUM 1
#define DATA 2
// Make larger sized integers from smaller sized integers
#define MAKEWORD16( ub, lb ) ((uint16_t)0x0000 | ((uint16_t)(ub) << 8) | (uint16_t)(lb) )
#define MAKEWORD32( uw, lw ) ((uint32_t)(0x0UL | ((uint32_t)(uw) << 16) | (uint32_t)(lw)) )
#define MAKEWORD32B( b3, b2, b1, b0 ) ((uint32_t)((uint32_t)(b3)<< 24) | ((uint32_t)(b2)<<16) | ((uint32_t)(b1)<<8) | ((uint32_t)(b0) )
// Used to extract smaller integers from larger sized intergers
#define LOWERBYTE( w ) (uint8_t)((w) & 0x00ff )
#define UPPERBYTE( w ) (uint8_t)(((w) & 0xff00) >> 8 )
#define UPPERWORD(lw) (uint16_t)(((lw) & 0xffff0000) >> 16 )
#define LOWERWORD(lw) (uint16_t)((lw) & 0x0000ffff)
// Macros to operate on a target and bitmask.
#define CLEARBIT( a, b ) ((a) = (a) & ~(b))
#define SETBIT( a, b ) ((a) = (a) | (b) )
#define TOGGLEBIT(a,b) ((a) = (a) ^ (b) )
// test bit macros operate using a bit mask.
#define ISBITSET( a, b ) ( ((a) & (b)) == (b) ? TRUE : FALSE )
#define ISBITCLEAR( a, b) ( (~(a) & (b)) == (b) ? TRUE : FALSE )
/** PRIVATE FUNCTIONS **/
//static void sf_SendSynchPacket( Port_t *thisport );
static uint16_t sf_crc16( uint16_t crc, uint8_t data );
static void sf_write_byte( Port_t *thisport, uint8_t c );
static void sf_SetSendTimeout( Port_t *thisport );
static uint16_t sf_CheckTimeout( Port_t *thisport );
static int16_t sf_DecodeState( Port_t *thisport, uint8_t c );
static int16_t sf_ReceiveState( Port_t *thisport, uint8_t c );
static void sf_SendPacket( Port_t *thisport );
static void sf_SendAckPacket( Port_t *thisport, uint8_t seqNumber);
static void sf_MakePacket( uint8_t *buf, const uint8_t * pdata, uint16_t length, uint8_t seqNo );
static int16_t sf_ReceivePacket(Port_t *thisport);
/* Flag bit masks...*/
#define SENT_SYNCH (0x01)
#define ACK_RECEIVED (0x02)
#define ACK_EXPECTED (0x04)
#define SSP_AWAITING_ACK 0
#define SSP_ACKED 1
#define SSP_IDLE 2
/** PRIVATE DATA **/
static const uint16_t CRC_TABLE[] = {
0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};
/** EXTERNAL DATA **/
/** EXTERNAL FUNCTIONS **/
/** VERIFICATION FUNCTIONS **/
/***********************************************************************************************************/
/*!
* \brief Initializes the communication port for use
* \param thisport = pointer to port structure to initialize
* \param info = config struct with default values.
* \return None.
*
* \note
* Must be called before calling the Send or REceive process functions.
*/
void ssp_Init( Port_t *thisport, const PortConfig_t* const info)
{
thisport->pfCallBack = info->pfCallBack;
thisport->pfSerialRead = info->pfSerialRead;
thisport->pfSerialWrite = info->pfSerialWrite;
thisport->pfGetTime = info->pfGetTime;
thisport->maxRetryCount = info->max_retry;
thisport->timeoutLen = info->timeoutLen;
thisport->txBufSize = info->txBufSize;
thisport->rxBufSize = info->rxBufSize;
thisport->txBuf = info->txBuf;
thisport->rxBuf = info->rxBuf;
thisport->retryCount = 0;
thisport->sendSynch = FALSE; //TRUE;
thisport->rxSeqNo = 255;
thisport->txSeqNo = 255;
thisport->SendState = SSP_IDLE;
}
/*!
* \brief Runs the send process, checks for receipt of ack, timeouts and resends if needed.
* \param thisport = which port to use
* \return SSP_TX_WAITING - waiting for a valid ACK to arrive
* \return SSP_TX_TIMEOUT - failed to receive a valid ACK in the timeout period, after retrying.
* \return SSP_TX_IDLE - not expecting a ACK packet (no current transmissions in progress)
* \return SSP_TX_ACKED - valid ACK received before timeout period.
*
* \note
*
*/
int16_t ssp_SendProcess( Port_t *thisport )
{
int16_t value = SSP_TX_WAITING;
if (thisport->SendState == SSP_AWAITING_ACK ) {
if (sf_CheckTimeout(thisport) == TRUE) {
if (thisport->retryCount < thisport->maxRetryCount) {
// Try again
sf_SendPacket(thisport);
sf_SetSendTimeout(thisport);
value = SSP_TX_WAITING;
} else {
// Give up, # of trys has exceded the limit
value = SSP_TX_TIMEOUT;
CLEARBIT( thisport->flags, ACK_RECEIVED);
thisport->SendState = SSP_IDLE;
}
} else {
value = SSP_TX_WAITING;
}
} else if( thisport->SendState == SSP_ACKED ) {
SETBIT( thisport->flags, ACK_RECEIVED);
value = SSP_TX_ACKED;
thisport->SendState = SSP_IDLE;
} else {
thisport->SendState = SSP_IDLE;
value = SSP_TX_IDLE;
}
return value;
}
/*!
* \brief Runs the receive process. fetches a byte at a time and runs the byte through the protocol receive state machine.
* \param thisport - which port to use.
* \return receive status.
*
* \note
*
*/
int16_t ssp_ReceiveProcess(Port_t *thisport)
{
int16_t b;
int16_t packet_status = SSP_RX_IDLE;
do {
b = thisport->pfSerialRead(); // attempt to read a char from the serial buffer
if (b != -1) {
packet_status = sf_ReceiveState(thisport, b); // process the newly received byte in the receive state machine
}
// keep going until either we received a full packet or there are no more bytes to process
} while (packet_status != SSP_RX_COMPLETE && b != -1);
return packet_status;
}
/*!
* \brief processes a single byte through the receive state machine.
* \param thisport = which port to use
* \return current receive status
*
* \note
*
*/
int16_t ssp_ReceiveByte(Port_t *thisport )
{
int16_t b;
int16_t packet_status = SSP_RX_IDLE;
b = thisport->pfSerialRead();
if( b != -1 ) {
packet_status = sf_ReceiveState(thisport, b);
}
return packet_status;
}
/*!
* \brief Sends a data packet and blocks until timeout or ack is received.
* \param thisport = which port to use
* \param data = pointer to data to send
* \param length = number of data bytes to send. Must be less than 254
* \return true = ack was received within number of retries
* \return false = ack was not received.
*
* \note
*
*/
uint16_t ssp_SendDataBlock( Port_t *thisport, uint8_t *data, uint16_t length )
{
int16_t packet_status = SSP_TX_WAITING;
uint16_t retval = FALSE;
packet_status = ssp_SendData( thisport, data, length ); // send the data
while( packet_status == SSP_TX_WAITING ) { // check the status
(void)ssp_ReceiveProcess( thisport ); // process any bytes received.
packet_status = ssp_SendProcess( thisport ); // check the send status
}
if( packet_status == SSP_TX_ACKED ) { // figure out what happened to the packet
retval = TRUE;
} else {
retval = FALSE;
}
return retval;
}
/*!
* \brief sends a chunk of data and does not block
* \param thisport = which port to use
* \param data = pointer to data to send
* \param length = number of bytes to send
* \return SSP_TX_BUFOVERRUN = tried to send too much data
* \return SSP_TX_WAITING = data sent and waiting for an ack to arrive
* \return SSP_TX_BUSY = a packet has already been sent, but not yet acked
*
* \note
*
*/
int16_t ssp_SendData( Port_t *thisport, const uint8_t *data, const uint16_t length )
{
int16_t value = SSP_TX_WAITING;
if( (length + 2) > thisport->txBufSize ) {
// TRYING to send too much data.
value = SSP_TX_BUFOVERRUN;
} else if( thisport->SendState == SSP_IDLE ) {
#ifdef ACTIVE_SYNCH
if( thisport->sendSynch == TRUE ) {
sf_SendSynchPacket(thisport);
}
#endif
#ifdef SYNCH_SEND
if( length == 0 ) {
// TODO this method could allow a task/user to start a synchronisation step if a zero is mistakenly passed to this function.
// could add a check for a NULL data pointer, or use some sort of static flag that can only be accessed by a static function
// that must be called before calling this function.
// we are attempting to send a synch packet
thisport->txSeqNo = 0; // make this zero to cause the other end to re-synch with us
SETBIT(thisport->flags, SENT_SYNCH);
} else {
// we are sending a data packet
CLEARBIT( thisport->txSeqNo, ACK_BIT ); // make sure we are not sending a ACK packet
thisport->txSeqNo++; // update the sequence number.
if( thisport->txSeqNo > 0x7F) { // check for sequence number rollover
thisport->txSeqNo = 1; // if we do have rollover then reset to 1 not zero,
// zero is reserviced for synchronization requests
}
}
#else
CLEARBIT( thisport->txSeqNo, ACK_BIT ); // make sure we are not sending a ACK packet
thisport->txSeqNo++; // update the sequence number.
if( thisport->txSeqNo > 0x7F) { // check for sequence number rollover
thisport->txSeqNo = 1; // if we do have rollover then reset to 1 not zero,
// zero is reserved for synchronization requests
}
#endif
CLEARBIT( thisport->flags, ACK_RECEIVED);
thisport->SendState = SSP_AWAITING_ACK;
value = SSP_TX_WAITING;
thisport->retryCount = 0; // zero out the retry counter for this transmission
sf_MakePacket( thisport->txBuf, data, length, thisport->txSeqNo );
sf_SendPacket( thisport ); // punch out the packet to the serial port
sf_SetSendTimeout( thisport ); // do the timeout values
} else {
// error we are already sending a packet. Need to wait for the current packet to be acked or timeout.
value = SSP_TX_BUSY;
}
return value;
}
/*!
* \brief Attempts to synchronize the sequence numbers with the other end of the connectin.
* \param thisport = which port to use
* \return true = success
* \return false = failed to receive an ACK to our synch request
*
* \note
* A. send a packet with a sequence number equal to zero
* B. if timed out then:
* send synch packet again
* increment try counter
* if number of tries exceed maximum try limit then exit
* C. goto A
*/
uint16_t ssp_Synchronise( Port_t *thisport )
{
int16_t packet_status;
uint16_t retval = FALSE;
#ifndef USE_SENDPACKET_DATA
thisport->txSeqNo = 0; // make this zero to cause the other end to re-synch with us
SETBIT(thisport->flags, SENT_SYNCH);
// TODO - should this be using ssp_SendPacketData()??
sf_MakePacket( thisport->txBuf, NULL, 0, thisport->txSeqNo ); // construct the packet
sf_SendPacket( thisport );
sf_SetSendTimeout( thisport );
thisport->SendState = SSP_AWAITING_ACK;
packet_status = SSP_TX_WAITING;
#else
packet_status = ssp_SendData( thisport, NULL, 0 );
#endif
while( packet_status == SSP_TX_WAITING ) { // we loop until we time out.
(void)ssp_ReceiveProcess( thisport ); // do the receive process
packet_status = ssp_SendProcess( thisport ); // do the send process
}
thisport->sendSynch = FALSE;
switch( packet_status ) {
case SSP_TX_ACKED:
retval = TRUE;
break;
case SSP_TX_BUSY: // intentional fall through.
case SSP_TX_TIMEOUT: // intentional fall through.
case SSP_TX_BUFOVERRUN:
retval = FALSE;
break;
default:
retval = FALSE;
break;
};
return retval;
}
/*!
* \brief sends out a preformatted packet for a give port
* \param thisport = which port to use.
* \return none.
*
* \note
* Packet should be formed through the use of sf_MakePacket before calling this function.
*/
static void sf_SendPacket(Port_t *thisport)
{
// add 3 to packet data length for: 1 length + 2 CRC (packet overhead)
uint8_t packetLen = thisport->txBuf[LENGTH] + 3;
// use the raw serial write function so the SYNC byte does not get 'escaped'
thisport->pfSerialWrite(SYNC);
for( uint8_t x = 0; x < packetLen; x++ ) {
sf_write_byte(thisport, thisport->txBuf[x] );
}
thisport->retryCount++;
}
/*!
* \brief converts data to transport layer protocol packet format.
* \param txbuf = buffer to use when forming the packet
* \param pdata = pointer to data to use
* \param length = number of bytes to use
* \param seqNo = sequence number of this packet
* \return none.
*
* \note
* 1. This function does not try to interpret ACK or SYNCH packets. This should
* be done by the caller of this function.
* 2. This function will attempt to format all data upto the size of the tx buffer.
* Any extra data beyond that will be ignored.
* 3. TODO: Should this function return an error if data length to be sent is greater th tx buffer size?
*
*/
void sf_MakePacket( uint8_t *txBuf, const uint8_t * pdata, uint16_t length, uint8_t seqNo )
{
uint16_t crc = 0xffff;
uint16_t bufPos = 0;
uint8_t b;
// add 1 for the seq. number
txBuf[LENGTH] = length + 1;
txBuf[SEQNUM] = seqNo;
crc = sf_crc16( crc, seqNo );
length = length + 2; // add two for the length and seqno bytes which are added before the loop.
for( bufPos = 2; bufPos < length; bufPos++ ) {
b = *pdata++;
txBuf[bufPos] = b;
crc = sf_crc16( crc, b ); // update CRC value
}
txBuf[bufPos++] = LOWERBYTE(crc);
txBuf[bufPos] = UPPERBYTE(crc);
}
/*!
* \brief sends out an ack packet to given sequence number
* \param thisport = which port to use
* \param seqNumber = sequence number of the packet we would like to ack
* \return none.
*
* \note
*
*/
static void sf_SendAckPacket( Port_t *thisport, uint8_t seqNumber)
{
uint8_t AckSeqNumber = SETBIT( seqNumber, ACK_BIT );
// create the packet, note we pass AckSequenceNumber directly
sf_MakePacket( thisport->txBuf, NULL, 0, AckSeqNumber );
sf_SendPacket( thisport );
// we don't set the timeout for an ACK because we don't ACK our ACKs in this protocol
}
/*!
* \brief writes a byte out the output channel. Adds escape byte where needed
* \param thisport = which port to use
* \param c = byte to send
* \return none.
*
* \note
*
*/
static void sf_write_byte( Port_t *thisport, uint8_t c )
{
if( c == SYNC ) { // check for SYNC byte
thisport->pfSerialWrite( ESC ); // since we are not starting a packet we must ESCAPE the SYNCH byte
thisport->pfSerialWrite( ESC_SYNC ); // now send the escaped synch char
} else if( c == ESC ) { // Check for ESC character
thisport->pfSerialWrite( ESC ); // if it is, we need to send it twice
thisport->pfSerialWrite( ESC );
} else {
thisport->pfSerialWrite( c ); // otherwise write the byte to serial port
}
}
/************************************************************************************************************
*
* NAME: uint16_t ssp_crc16( uint16_t crc, uint16_t data )
* DESCRIPTION: Uses crc_table to calculate new crc
* ARGUMENTS:
* arg1: crc
* arg2: data - byte to calculate into CRC
* RETURN: New crc
* CREATED: 5/8/02
*
*************************************************************************************************************/
/*!
* \brief calculates the new CRC value for 'data'
* \param crc = current CRC value
* \param data = new byte
* \return updated CRC value
*
* \note
*
*/
static uint16_t sf_crc16( uint16_t crc, uint8_t data )
{
return (crc >> 8) ^ CRC_TABLE[( crc ^ data ) & 0x00FF ];
}
/*!
* \brief sets the timeout for the given packet
* \param thisport = which port to use
* \return none.
*
* \note
*
*/
static void sf_SetSendTimeout( Port_t *thisport )
{
uint32_t timeout;
timeout = thisport->pfGetTime() + thisport->timeoutLen;
thisport->timeout = timeout;
}
/*!
* \brief checks to see if a timeout occured
* \param thisport = which port to use
* \return true = a timeout has occurred
* \return false = has not timed out
*
* \note
*
*/
static uint16_t sf_CheckTimeout( Port_t *thisport )
{
uint16_t retval = FALSE;
uint32_t current_time;
current_time = thisport->pfGetTime();
if( current_time > thisport->timeout ) {
retval = TRUE;
}
return retval;
}
/****************************************************************************
* NAME: sf_ReceiveState
* DESC: Implements the receive state handling code for escaped and unescaped data
* ARGS: thisport - which port to operate on
* c - incoming byte
* RETURN:
* CREATED:
* NOTES:
* 1. change from using pointer to functions.
****************************************************************************/
/*!
* \brief implements the receive state handling code for escaped and unescaped data
* \param thisport = which port to use
* \param c = byte to process through the receive state machine
* \return receive status
*
* \note
*
*/
static int16_t sf_ReceiveState( Port_t *thisport, uint8_t c )
{
int16_t retval = SSP_RX_RECEIVING;
switch( thisport->InputState ) {
case state_unescaped_e:
if( c == SYNC ) {
thisport->DecodeState = decode_len1_e;
} else if ( c == ESC ) {
thisport->InputState = state_escaped_e;
} else {
retval = sf_DecodeState( thisport, c);
}
break; // end of unescaped state.
case state_escaped_e:
thisport->InputState = state_unescaped_e;
if( c == SYNC ) {
thisport->DecodeState = decode_len1_e;
} else if (c == ESC_SYNC ) {
retval = sf_DecodeState( thisport, SYNC);
} else {
retval = sf_DecodeState( thisport, c);
}
break; // end of the escaped state.
default:
break;
}
return retval;
}
/****************************************************************************
* NAME: sf_DecodeState
* DESC: Implements the receive state finite state machine
* ARGS: thisport - which port to operate on
* c - incoming byte
* RETURN:
* CREATED:
* NOTES:
* 1. change from using pointer to functions.
****************************************************************************/
/*!
* \brief implements the receiving decoding state machine
* \param thisport = which port to use
* \param c = byte to process
* \return receive status
*
* \note
*
*/
static int16_t sf_DecodeState( Port_t *thisport, uint8_t c )
{
int16_t retval;
switch( thisport->DecodeState ) {
case decode_idle_e:
// 'c' is ignored in this state as the only way to leave the idle state is
// recognition of the SYNC byte in the sf_ReceiveState function.
retval = SSP_RX_IDLE;
break;
case decode_len1_e:
thisport->rxBuf[LENGTH]= c;
thisport->rxBufLen = c;
if( thisport->rxBufLen <= thisport->rxBufSize ) {
thisport->DecodeState = decode_seqNo_e;
retval = SSP_RX_RECEIVING;
} else {
thisport->DecodeState = decode_idle_e;
retval = SSP_RX_IDLE;
}
break;
case decode_seqNo_e:
thisport->rxBuf[SEQNUM] = c;
thisport->crc = 0xffff;
thisport->rxBufLen--; // subtract 1 for the seq. no.
thisport->rxBufPos = 2;
thisport->crc = sf_crc16( thisport->crc, c );
if( thisport->rxBufLen > 0 ) {
thisport->DecodeState = decode_data_e;
} else {
thisport->DecodeState = decode_crc1_e;
}
retval = SSP_RX_RECEIVING;
break;
case decode_data_e:
thisport->rxBuf[ (thisport->rxBufPos)++] = c;
thisport->crc = sf_crc16( thisport->crc, c );
if( thisport->rxBufPos == (thisport->rxBufLen+2) ) {
thisport->DecodeState = decode_crc1_e;
}
retval = SSP_RX_RECEIVING;
break;
case decode_crc1_e:
thisport->crc = sf_crc16( thisport->crc, c );
thisport->DecodeState = decode_crc2_e;
retval = SSP_RX_RECEIVING;
break;
case decode_crc2_e:
thisport->DecodeState = decode_idle_e;
// verify the CRC value for the packet
if( sf_crc16( thisport->crc, c) == 0) {
// TODO shouldn't the return value of sf_ReceivePacket() be checked?
sf_ReceivePacket( thisport );
retval = SSP_RX_COMPLETE;
} else {
thisport->RxError++;
retval = SSP_RX_IDLE;
}
break;
default:
thisport->DecodeState = decode_idle_e; // unknown state so reset to idle state and wait for the next start of a packet.
retval = SSP_RX_IDLE;
break;
}
return retval;
}
/************************************************************************************************************
*
* NAME: int16_t sf_ReceivePacket( )
* DESCRIPTION: Receive one packet, assumed that data is in rec.buff[]
* ARGUMENTS:
* RETURN: 0 . no new packet was received, could be ack or same packet
* 1 . new packet received
* SSP_PACKET_?
* SSP_PACKET_COMPLETE
* SSP_PACKET_ACK
* CREATED: 5/8/02
*
*************************************************************************************************************/
/*!
* \brief receive one packet. calls the callback function if needed.
* \param thisport = which port to use
* \return true = valid data packet received.
* \return false = otherwise
*
* \note
*
* Created: Oct 7, 2010 12:07:22 AM by joe
*/
static int16_t sf_ReceivePacket(Port_t *thisport)
{
int16_t value = FALSE;
if( ISBITSET(thisport->rxBuf[SEQNUM], ACK_BIT ) ) {
// Received an ACK packet, need to check if it matches the previous sent packet
if( ( thisport->rxBuf[SEQNUM] & 0x7F) == (thisport->txSeqNo & 0x7f)) {
// It matches the last packet sent by us
SETBIT( thisport->txSeqNo, ACK_BIT );
thisport->SendState = SSP_ACKED;
value = FALSE;
}
// else ignore the ACK packet
} else {
// Received a 'data' packet, figure out what type of packet we received...
if( thisport->rxBuf[SEQNUM] == 0 ) {
// Synchronize sequence number with host
#ifdef ACTIVE_SYNCH
thisport->sendSynch = TRUE;
#endif
sf_SendAckPacket( thisport, thisport->rxBuf[SEQNUM] );
thisport->rxSeqNo = 0;
value = FALSE;
} else if( thisport->rxBuf[SEQNUM] == thisport->rxSeqNo ) {
// Already seen this packet, just ack it, don't act on the packet.
sf_SendAckPacket( thisport, thisport->rxBuf[SEQNUM] );
value = FALSE;
} else {
//New Packet
thisport->rxSeqNo = thisport->rxBuf[SEQNUM];
// Let the application do something with the data/packet.
if( thisport->pfCallBack != NULL ) {
// skip the first two bytes (length and seq. no.) in the buffer.
thisport->pfCallBack( &(thisport->rxBuf[2]), thisport->rxBufLen);
}
// after we send the ACK, it is possible for the host to send a new packet.
// Thus the application needs to copy the data and reset the receive buffer
// inside of thisport->pfCallBack()
sf_SendAckPacket( thisport, thisport->rxBuf[SEQNUM] );
value = TRUE;
}
}
return value;
}

229
flight/Bootloaders/OpenPilot/ssp_test.c Normal file
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// test functions for the SSP module.
// this module performs unit test on the SSP functions.
#include "ssp.h"
#include "buffer.h"
#ifndef true
#define true 1
#endif
#ifndef false
#define false 0
#endif
#define MAX_PACKET_DATA_LEN 255
#define MAX_PACKET_BUF_SIZE (1+1+255+2)
// master buffers...
uint8_t masterTxBuf[MAX_PACKET_BUF_SIZE];
uint8_t masterRxBuf[MAX_PACKET_BUF_SIZE];
// slave buffers...
uint8_t slaveTxBuf[MAX_PACKET_BUF_SIZE];
uint8_t slaveRxBuf[MAX_PACKET_BUF_SIZE];
void masterCallBack(uint8_t *buf, uint16_t len);
int16_t masterSerialRead(void);
void masterSerialWrite(uint8_t);
uint32_t masterGetTime(void);
void slaveCallBack(uint8_t *buf, uint16_t len);
int16_t slaveSerialRead(void);
void slaveSerialWrite(uint8_t);
uint32_t slaveGetTime(void);
PortConfig_t masterPortConfig = {
.rxBuf = masterRxBuf,
.rxBufSize = MAX_PACKET_DATA_LEN,
.txBuf = masterTxBuf,
.txBufSize = 255,
.max_retry = 3,
.timeoutLen = 100,
.pfCallBack = masterCallBack,
.pfSerialRead = masterSerialRead,
.pfSerialWrite = masterSerialWrite,
.pfGetTime = masterGetTime,
};
PortConfig_t slavePortConfig = {
.rxBuf = slaveRxBuf,
.rxBufSize = MAX_PACKET_DATA_LEN,
.txBuf = slaveTxBuf,
.txBufSize = 255,
.max_retry = 3,
.timeoutLen = 100,
.pfCallBack = slaveCallBack,
.pfSerialRead = slaveSerialRead,
.pfSerialWrite = slaveSerialWrite,
.pfGetTime = slaveGetTime,
};
Port_t master_port;
Port_t slave_port;
cBuffer m2sBuffer;
cBuffer s2mBuffer;
#define BUFFER 1024
// buffer space for the simulated serial buffers.
uint8_t m2sDataBuffer[BUFFER];
uint8_t s2mDataBuffer[BUFFER];
void ssp_test(void)
{
uint8_t masterSendBuf[255];
// uint8_t slaveSendBuf[255];
Port_t *master = &master_port;
Port_t *slave = &slave_port;
int16_t packet_status;
int16_t retval;
uint8_t master_respond = TRUE;
uint8_t slave_respond = TRUE;
uint8_t master_send_respond = TRUE;
bufferInit(&m2sBuffer, m2sDataBuffer, BUFFER);
bufferInit(&s2mBuffer, s2mDataBuffer, BUFFER);
ssp_Init( master, &masterPortConfig);
ssp_Init( slave, &slavePortConfig);
masterSendBuf[0] = 0;
masterSendBuf[1] = 1;
masterSendBuf[2] = 2;
masterSendBuf[3] = 3;
masterSendBuf[4] = 4;
ssp_Synchronise(master);
while (1) {
packet_status = ssp_SendData( master, masterSendBuf, 5 ); // send the data
while( packet_status == SSP_TX_WAITING ) { // check the status
if( slave_respond == TRUE ) {
(void)ssp_ReceiveProcess(slave); // process simulated input to the slave
}
if( master_respond == TRUE ) {
(void)ssp_ReceiveProcess( master ); // process any bytes received.
}
if( master_send_respond == TRUE ) {
packet_status = ssp_SendProcess( master );// check the packet
}
}
if (packet_status == SSP_TX_ACKED ) {
retval = TRUE;
} else {
// figure out what happened to the packet
// possible errors are: timeout, busy, bufoverrun (tried to send too much data.
retval = FALSE;
}
// just a more explicit way to see what happened...
switch( packet_status ) {
case SSP_TX_ACKED:
// quick data manipulation to see something different...
for (int32_t x = 0; x < 5; ++x) {
masterSendBuf[x] += 5;
}
retval = TRUE;
break;
case SSP_TX_BUSY:
retval = FALSE;
break;
case SSP_TX_TIMEOUT:
retval = FALSE;
break;
case SSP_TX_BUFOVERRUN:
retval = false;
break;
default:
retval = -3;
break;
}
#ifdef OLD_CODE
do {
packetStatus = ssp_SendPacketData( master, masterSendBuf, 5);
if( packetStatus == SSP_TX_FAIL) {
ssp_ReceiveProcess(slave);
ssp_ReceiveProcess(master);
ssp_SendProcess(master);
}
} while( packetStatus != SSP_TX_WAITING );
do {
// let the slave process simulated input.
ssp_ReceiveProcess(slave);
// process simulated input from the slave to master. Slave 'may' have sent an ACK
if( ssp_ReceiveProcess(master) == SSP_RX_COMPLETE) {
// at this point an ACK or 'data' packet was received.
}
packetStatus = ssp_SendProcess(master);
} while ( packetStatus == SSP_TX_WAITING);
#endif
}
}
// these functions implement a simulated serial in/out for both a master
// and a slave device. In reality these functions do not send anything out
// but just puts them into a circular buffer.
// In a real system these would use the PIOS_COM_xxxx functions.
void masterCallBack(uint8_t *buf, uint16_t len)
{
len = len;
}
// simulates checking for character from a serial buffer.
int16_t masterSerialRead(void)
{
int16_t retval = -1;
static uint16_t count = 0;
if( bufferBufferedData(&s2mBuffer)) {
retval = bufferGetFromFront( &s2mBuffer);
}
count++;
if( count % 5 == 0 ) {
ssp_ReceiveByte(&slave_port);
}
return retval;
}
void masterSerialWrite(uint8_t b)
{
bufferAddToEnd( &m2sBuffer, b);
}
uint32_t masterTime = 0;
uint32_t slaveTime = 0;
uint32_t masterGetTime(void)
{
masterTime++;
return masterTime;
}
void slaveCallBack(uint8_t *buf, uint16_t len)
{
len = len;
}
int16_t slaveSerialRead(void)
{
int16_t retval = -1;
if( bufferBufferedData(&m2sBuffer)) {
retval = bufferGetFromFront( &m2sBuffer);
}
return retval;
}
void slaveSerialWrite(uint8_t b)
{
bufferAddToEnd( &s2mBuffer, b);
}
uint32_t slaveGetTime(void)
{
slaveTime++;
return slaveTime;
}