ardupilot/libraries/AP_RCProtocol/AP_RCProtocol_SUMD.cpp
Michael du Breuil bbcc31ecec AP_RCProtocol: Refactor SUMD to remove legacy cruft
Of particular note this removes the partial SUMH support. This has been
broken as far back as 2018, as we only called add_input() if we were in
the SUMD or SUMD failsafe cases, which meant SUMH didn't work. This
commits to that path, and removes all the 8 bit CRC, SUMH support.

This also refactors a number of things for readability (condensing white
space, simplifying guards around debug code). Many of the debugs could
probably be removed, but this simplifies it.

This was tested against the RCProtocol example test, and everything
there reports a pass.
2023-06-27 10:57:06 +10:00

211 lines
7.4 KiB
C++

/*
SUMD decoder, based on PX4Firmware/src/rc/lib/rc/sumd.c from PX4Firmware
modified for use in AP_HAL_* by Andrew Tridgell
*/
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/*
* @file sumd.h
*
* RC protocol definition for Graupner HoTT transmitter (SUMD/SUMH Protocol)
*
* @author Marco Bauer <marco@wtns.de>
*/
#include "AP_RCProtocol_config.h"
#if AP_RCPROTOCOL_SUMD_ENABLED
#include "AP_RCProtocol_SUMD.h"
#include <AP_Math/crc.h>
#define SUMD_HEADER_LENGTH 3
#define SUMD_HEADER_ID 0xA8
#define SUMD_ID_SUMH 0x00
#define SUMD_ID_SUMD 0x01
#define SUMD_ID_FAILSAFE 0x81
// #define SUMD_DEBUG
extern const AP_HAL::HAL& hal;
void AP_RCProtocol_SUMD::process_pulse(uint32_t width_s0, uint32_t width_s1)
{
uint8_t b;
if (ss.process_pulse(width_s0, width_s1, b)) {
_process_byte(ss.get_byte_timestamp_us(), b);
}
}
void AP_RCProtocol_SUMD::_process_byte(uint32_t timestamp_us, uint8_t byte)
{
if (timestamp_us - last_packet_us > 5000U) {
_decode_state = SUMD_DECODE_STATE_UNSYNCED;
}
switch (_decode_state) {
case SUMD_DECODE_STATE_UNSYNCED:
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_UNSYNCED \n") ;
#endif
if (byte == SUMD_HEADER_ID) {
_rxlen = 0;
_crc16 = crc_xmodem_update(0, byte);
_decode_state = SUMD_DECODE_STATE_GOT_HEADER;
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_HEADER: %x \n", byte) ;
#endif
last_packet_us = timestamp_us;
}
break;
case SUMD_DECODE_STATE_GOT_HEADER:
if ((byte == SUMD_ID_SUMD) || (byte == SUMD_ID_FAILSAFE)) {
_rxpacket.status = byte;
_crc16 = crc_xmodem_update(_crc16, byte);
_decode_state = SUMD_DECODE_STATE_GOT_STATE;
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_STATE: %x \n", byte) ;
#endif
} else {
_decode_state = SUMD_DECODE_STATE_UNSYNCED;
}
break;
case SUMD_DECODE_STATE_GOT_STATE:
if (byte >= 2 && byte <= SUMD_MAX_CHANNELS) {
_rxpacket.length = byte;
_crc16 = crc_xmodem_update(_crc16, byte);
_rxlen++;
_decode_state = SUMD_DECODE_STATE_GOT_LEN;
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_LEN: %x (%d) \n", byte, byte) ;
#endif
} else {
_decode_state = SUMD_DECODE_STATE_UNSYNCED;
}
break;
case SUMD_DECODE_STATE_GOT_LEN:
_rxpacket.sumd_data[_rxlen] = byte;
_crc16 = crc_xmodem_update(_crc16, byte);
_rxlen++;
if (_rxlen <= ((_rxpacket.length * 2))) {
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_DATA[%d]: %x\n", _rxlen - 2, byte) ;
#endif
} else {
_decode_state = SUMD_DECODE_STATE_GOT_DATA;
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_DATA -- finish --\n") ;
#endif
}
break;
case SUMD_DECODE_STATE_GOT_DATA:
_rxpacket.crc16_high = byte;
_decode_state = SUMD_DECODE_STATE_GOT_CRC;
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_CRC16[1]: %x [%x]\n", byte, ((_crc16 >> 8) & 0xff)) ;
#endif
break;
case SUMD_DECODE_STATE_GOT_CRC:
#ifdef SUMD_DEBUG
hal.console->printf(" SUMD_DECODE_STATE_GOT_CRC[2]: %x [%x]\n\n", byte, (_crc16 & 0xff)) ;
#endif
log_data(AP_RCProtocol::SUMD, timestamp_us, _rxpacket.sumd_data, _rxlen);
if (_crc16 == (uint16_t)(_rxpacket.crc16_high << 8) + byte) {
#ifdef SUMD_DEBUG
hal.console->printf(" CRC - OK \n") ;
hal.console->printf(" Got valid SUMD Packet\n") ;
hal.console->printf(" RXLEN: %d [Chans: %d] \n\n", _rxlen - 1, (_rxlen - 1) / 2) ;
#endif
uint16_t values[SUMD_MAX_CHANNELS];
/* received Channels */
if ((uint16_t)_rxpacket.length > SUMD_MAX_CHANNELS) {
_rxpacket.length = (uint8_t) SUMD_MAX_CHANNELS;
}
/* decode the actual packet */
/* reorder first 4 channels */
/* ch1 = roll -> sumd = ch2 */
values[0] = (uint16_t)((_rxpacket.sumd_data[1 * 2 + 1] << 8) | _rxpacket.sumd_data[1 * 2 + 2]) >> 3;
/* ch2 = pitch -> sumd = ch2 */
values[1] = (uint16_t)((_rxpacket.sumd_data[2 * 2 + 1] << 8) | _rxpacket.sumd_data[2 * 2 + 2]) >> 3;
/* ch3 = throttle -> sumd = ch2 */
values[2] = (uint16_t)((_rxpacket.sumd_data[0 * 2 + 1] << 8) | _rxpacket.sumd_data[0 * 2 + 2]) >> 3;
/* ch4 = yaw -> sumd = ch2 */
values[3] = (uint16_t)((_rxpacket.sumd_data[3 * 2 + 1] << 8) | _rxpacket.sumd_data[3 * 2 + 2]) >> 3;
/* we start at channel 5(index 4) */
for (uint8_t i = 4; i < _rxpacket.length; i++) {
#ifdef SUMD_DEBUG
hal.console->printf("ch[%u] : %x %x [ %x %d ]\n", i + 1, _rxpacket.sumd_data[i * 2 + 1], _rxpacket.sumd_data[i * 2 + 2],
((_rxpacket.sumd_data[i * 2 + 1] << 8) | _rxpacket.sumd_data[i * 2 + 2]) >> 3,
((_rxpacket.sumd_data[i * 2 + 1] << 8) | _rxpacket.sumd_data[i * 2 + 2]) >> 3);
#endif
values[i] = (uint16_t)((_rxpacket.sumd_data[i * 2 + 1] << 8) | _rxpacket.sumd_data[i * 2 + 2]) >> 3;
}
add_input(_rxpacket.length, values, (_rxpacket.status == SUMD_ID_FAILSAFE));
#ifdef SUMD_DEBUG
} else {
hal.console->printf(" CRC - fail 0x%X 0x%X\n", _crc16, (uint16_t)(_rxpacket.crc16_high << 8) + byte);
#endif
}
_decode_state = SUMD_DECODE_STATE_UNSYNCED;
break;
}
}
void AP_RCProtocol_SUMD::process_byte(uint8_t byte, uint32_t baudrate)
{
if (baudrate != 115200) {
return;
}
_process_byte(AP_HAL::micros(), byte);
}
#endif // AP_RCPROTOCOL_SUMD_ENABLED