/****************************************************************************
*
* Copyright (C) 2013 PX4 Development Team. All rights reserved.
* Author: Thomas Gubler <thomasgubler@student.ethz.ch>
* Julian Oes <joes@student.ethz.ch>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/* @file U-Blox protocol implementation */
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <systemlib/err.h>
#include <uORB/uORB.h>
#include <uORB/topics/vehicle_gps_position.h>
#include <drivers/drv_hrt.h>
#include "ubx.h"
UBX::UBX() :
_config_state(UBX_CONFIG_STATE_PRT),
_waiting_for_ack(false),
_new_nav_posllh(false),
_new_nav_timeutc(false),
_new_nav_dop(false),
_new_nav_sol(false),
_new_nav_velned(false)
{
reset();
}
UBX::~UBX()
{
}
void
UBX::reset()
{
decodeInit();
_config_state = UBX_CONFIG_STATE_PRT;
_waiting_for_ack = false;
}
void
UBX::configure(uint8_t *buffer, int &length, const unsigned max_length, bool &baudrate_changed, unsigned &baudrate)
{
/* make sure the buffer, where the message is written to, is long enough */
assert(sizeof(type_gps_bin_cfg_prt_packet_t)+2 <= max_length);
/* Only send a new config message when we got the ACK of the last one,
* otherwise we might not configure all the messages because the ACK comes from an older/previos CFD command
* reason being that the ACK only includes CFG-MSG but not to which NAV MSG it belongs.
*/
if (!_waiting_for_ack) {
_waiting_for_ack = true;
if (_config_state == UBX_CONFIG_STATE_CONFIGURED) {
/* This should never happen, the parser should set the flag,
* if it should be reconfigured, reset() should be called first.
*/
warnx("ubx: already configured");
_waiting_for_ack = false;
return;
} else if (_config_state == UBX_CONFIG_STATE_PRT) {
/* Send a CFG-PRT message to set the UBX protocol for in and out
* and leave the baudrate as it is, we just want an ACK-ACK from this
*/
type_gps_bin_cfg_prt_packet_t cfg_prt_packet;
/* Set everything else of the packet to 0, otherwise the module wont accept it */
memset(&cfg_prt_packet, 0, sizeof(cfg_prt_packet));
/* Define the package contents, don't change the baudrate */
cfg_prt_packet.clsID = UBX_CLASS_CFG;
cfg_prt_packet.msgID = UBX_MESSAGE_CFG_PRT;
cfg_prt_packet.length = UBX_CFG_PRT_LENGTH;
cfg_prt_packet.portID = UBX_CFG_PRT_PAYLOAD_PORTID;
cfg_prt_packet.mode = UBX_CFG_PRT_PAYLOAD_MODE;
cfg_prt_packet.baudRate = baudrate;
cfg_prt_packet.inProtoMask = UBX_CFG_PRT_PAYLOAD_INPROTOMASK;
cfg_prt_packet.outProtoMask = UBX_CFG_PRT_PAYLOAD_OUTPROTOMASK;
/* Calculate the checksum now */
addChecksumToMessage((uint8_t*)&cfg_prt_packet, sizeof(cfg_prt_packet));
/* Start with the two sync bytes */
buffer[0] = UBX_SYNC1;
buffer[1] = UBX_SYNC2;
/* Copy it to the buffer that will be written back in the main gps driver */
memcpy(&(buffer[2]), &cfg_prt_packet, sizeof(cfg_prt_packet));
/* Set the length of the packet (plus the 2 sync bytes) */
length = sizeof(cfg_prt_packet)+2;
} else if (_config_state == UBX_CONFIG_STATE_PRT_NEW_BAUDRATE) {
/* Send a CFG-PRT message again, this time change the baudrate */
type_gps_bin_cfg_prt_packet_t cfg_prt_packet;
memset(&cfg_prt_packet, 0, sizeof(cfg_prt_packet));
cfg_prt_packet.clsID = UBX_CLASS_CFG;
cfg_prt_packet.msgID = UBX_MESSAGE_CFG_PRT;
cfg_prt_packet.length = UBX_CFG_PRT_LENGTH;
cfg_prt_packet.portID = UBX_CFG_PRT_PAYLOAD_PORTID;
cfg_prt_packet.mode = UBX_CFG_PRT_PAYLOAD_MODE;
cfg_prt_packet.baudRate = UBX_CFG_PRT_PAYLOAD_BAUDRATE;
cfg_prt_packet.inProtoMask = UBX_CFG_PRT_PAYLOAD_INPROTOMASK;
cfg_prt_packet.outProtoMask = UBX_CFG_PRT_PAYLOAD_OUTPROTOMASK;
addChecksumToMessage((uint8_t*)&cfg_prt_packet, sizeof(cfg_prt_packet));
buffer[0] = UBX_SYNC1;
buffer[1] = UBX_SYNC2;
memcpy(&(buffer[2]), &cfg_prt_packet, sizeof(cfg_prt_packet));
length = sizeof(cfg_prt_packet)+2;
/* If the new baudrate will be different from the current one, we should report that back to the driver */
if (UBX_CFG_PRT_PAYLOAD_BAUDRATE != baudrate) {
baudrate=UBX_CFG_PRT_PAYLOAD_BAUDRATE;
baudrate_changed = true;
/* Don't wait for an ACK, we're switching baudrate and we might never get,
* after that, start fresh */
reset();
}
} else if (_config_state == UBX_CONFIG_STATE_RATE) {
/* send a CFT-RATE message to define update rate */
type_gps_bin_cfg_rate_packet_t cfg_rate_packet;
memset(&cfg_rate_packet, 0, sizeof(cfg_rate_packet));
cfg_rate_packet.clsID = UBX_CLASS_CFG;
cfg_rate_packet.msgID = UBX_MESSAGE_CFG_RATE;
cfg_rate_packet.length = UBX_CFG_RATE_LENGTH;
cfg_rate_packet.measRate = UBX_CFG_RATE_PAYLOAD_MEASRATE;
cfg_rate_packet.navRate = UBX_CFG_RATE_PAYLOAD_NAVRATE;
cfg_rate_packet.timeRef = UBX_CFG_RATE_PAYLOAD_TIMEREF;
addChecksumToMessage((uint8_t*)&cfg_rate_packet, sizeof(cfg_rate_packet));
buffer[0] = UBX_SYNC1;
buffer[1] = UBX_SYNC2;
memcpy(&(buffer[2]), &cfg_rate_packet, sizeof(cfg_rate_packet));
length = sizeof(cfg_rate_packet)+2;
} else if (_config_state == UBX_CONFIG_STATE_NAV5) {
/* send a NAV5 message to set the options for the internal filter */
type_gps_bin_cfg_nav5_packet_t cfg_nav5_packet;
memset(&cfg_nav5_packet, 0, sizeof(cfg_nav5_packet));
cfg_nav5_packet.clsID = UBX_CLASS_CFG;
cfg_nav5_packet.msgID = UBX_MESSAGE_CFG_NAV5;
cfg_nav5_packet.length = UBX_CFG_NAV5_LENGTH;
cfg_nav5_packet.mask = UBX_CFG_NAV5_PAYLOAD_MASK;
cfg_nav5_packet.dynModel = UBX_CFG_NAV5_PAYLOAD_DYNMODEL;
cfg_nav5_packet.fixMode = UBX_CFG_NAV5_PAYLOAD_FIXMODE;
addChecksumToMessage((uint8_t*)&cfg_nav5_packet, sizeof(cfg_nav5_packet));
buffer[0] = UBX_SYNC1;
buffer[1] = UBX_SYNC2;
memcpy(&(buffer[2]), &cfg_nav5_packet, sizeof(cfg_nav5_packet));
length = sizeof(cfg_nav5_packet)+2;
} else {
/* Catch the remaining config states here, they all need the same packet type */
type_gps_bin_cfg_msg_packet_t cfg_msg_packet;
memset(&cfg_msg_packet, 0, sizeof(cfg_msg_packet));
cfg_msg_packet.clsID = UBX_CLASS_CFG;
cfg_msg_packet.msgID = UBX_MESSAGE_CFG_MSG;
cfg_msg_packet.length = UBX_CFG_MSG_LENGTH;
/* Choose fast 5Hz rate for all messages except SVINFO which is big and not important */
cfg_msg_packet.rate[1] = UBX_CFG_MSG_PAYLOAD_RATE1_5HZ;
switch (_config_state) {
case UBX_CONFIG_STATE_MSG_NAV_POSLLH:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_POSLLH;
break;
case UBX_CONFIG_STATE_MSG_NAV_TIMEUTC:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_TIMEUTC;
break;
case UBX_CONFIG_STATE_MSG_NAV_DOP:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_DOP;
break;
case UBX_CONFIG_STATE_MSG_NAV_SVINFO:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_SVINFO;
/* For satelites info 1Hz is enough */
cfg_msg_packet.rate[1] = UBX_CFG_MSG_PAYLOAD_RATE1_1HZ;
break;
case UBX_CONFIG_STATE_MSG_NAV_SOL:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_SOL;
break;
case UBX_CONFIG_STATE_MSG_NAV_VELNED:
cfg_msg_packet.msgClass_payload = UBX_CLASS_NAV;
cfg_msg_packet.msgID_payload = UBX_MESSAGE_NAV_VELNED;
break;
// case UBX_CONFIG_STATE_MSG_RXM_SVSI:
// cfg_msg_packet.msgClass_payload = UBX_CLASS_RXM;
// cfg_msg_packet.msgID_payload = UBX_MESSAGE_RXM_SVSI;
// break;
default:
break;
}
addChecksumToMessage((uint8_t*)&cfg_msg_packet, sizeof(cfg_msg_packet));
buffer[0] = UBX_SYNC1;
buffer[1] = UBX_SYNC2;
memcpy(&(buffer[2]), &cfg_msg_packet, sizeof(cfg_msg_packet));
length = sizeof(cfg_msg_packet)+2;
}
}
}
void
UBX::parse(uint8_t b, struct vehicle_gps_position_s *gps_position, bool &config_needed, bool &pos_updated)
{
switch (_decode_state) {
/* First, look for sync1 */
case UBX_DECODE_UNINIT:
if (b == UBX_SYNC1) {
_decode_state = UBX_DECODE_GOT_SYNC1;
}
break;
/* Second, look for sync2 */
case UBX_DECODE_GOT_SYNC1:
if (b == UBX_SYNC2) {
_decode_state = UBX_DECODE_GOT_SYNC2;
} else {
/* Second start symbol was wrong, reset state machine */
decodeInit();
}
break;
/* Now look for class */
case UBX_DECODE_GOT_SYNC2:
/* everything except sync1 and sync2 needs to be added to the checksum */
addByteToChecksum(b);
/* check for known class */
switch (b) {
case UBX_CLASS_ACK:
_decode_state = UBX_DECODE_GOT_CLASS;
_message_class = ACK;
break;
case UBX_CLASS_NAV:
_decode_state = UBX_DECODE_GOT_CLASS;
_message_class = NAV;
break;
// case UBX_CLASS_RXM:
// _decode_state = UBX_DECODE_GOT_CLASS;
// _message_class = RXM;
// break;
case UBX_CLASS_CFG:
_decode_state = UBX_DECODE_GOT_CLASS;
_message_class = CFG;
break;
default: //unknown class: reset state machine
decodeInit();
break;
}
break;
case UBX_DECODE_GOT_CLASS:
addByteToChecksum(b);
switch (_message_class) {
case NAV:
switch (b) {
case UBX_MESSAGE_NAV_POSLLH:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_POSLLH;
break;
case UBX_MESSAGE_NAV_SOL:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_SOL;
break;
case UBX_MESSAGE_NAV_TIMEUTC:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_TIMEUTC;
break;
case UBX_MESSAGE_NAV_DOP:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_DOP;
break;
case UBX_MESSAGE_NAV_SVINFO:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_SVINFO;
break;
case UBX_MESSAGE_NAV_VELNED:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = NAV_VELNED;
break;
default: //unknown class: reset state machine, should not happen
decodeInit();
break;
}
break;
// case RXM:
// switch (b) {
// case UBX_MESSAGE_RXM_SVSI:
// _decode_state = UBX_DECODE_GOT_MESSAGEID;
// _message_id = RXM_SVSI;
// break;
//
// default: //unknown class: reset state machine, should not happen
// decodeInit();
// break;
// }
// break;
case CFG:
switch (b) {
case UBX_MESSAGE_CFG_NAV5:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = CFG_NAV5;
break;
default: //unknown class: reset state machine, should not happen
decodeInit();
break;
}
break;
case ACK:
switch (b) {
case UBX_MESSAGE_ACK_ACK:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = ACK_ACK;
break;
case UBX_MESSAGE_ACK_NAK:
_decode_state = UBX_DECODE_GOT_MESSAGEID;
_message_id = ACK_NAK;
break;
default: //unknown class: reset state machine, should not happen
decodeInit();
break;
}
break;
default: //should not happen because we set the class
warnx("UBX Error, we set a class that we don't know");
decodeInit();
config_needed = true;
break;
}
break;
case UBX_DECODE_GOT_MESSAGEID:
addByteToChecksum(b);
_payload_size = b; //this is the first length byte
_decode_state = UBX_DECODE_GOT_LENGTH1;
break;
case UBX_DECODE_GOT_LENGTH1:
addByteToChecksum(b);
_payload_size += b << 8; // here comes the second byte of length
_decode_state = UBX_DECODE_GOT_LENGTH2;
break;
case UBX_DECODE_GOT_LENGTH2:
/* Add to checksum if not yet at checksum byte */
if (_rx_count < _payload_size)
addByteToChecksum(b);
_rx_buffer[_rx_count] = b;
/* once the payload has arrived, we can process the information */
if (_rx_count >= _payload_size + 1) { //+1 because of 2 checksum bytes
switch (_message_id) { //this enum is unique for all ids --> no need to check the class
case NAV_POSLLH: {
// printf("GOT NAV_POSLLH MESSAGE\n");
gps_bin_nav_posllh_packet_t *packet = (gps_bin_nav_posllh_packet_t *) _rx_buffer;
//Check if checksum is valid and the store the gps information
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
gps_position->lat = packet->lat;
gps_position->lon = packet->lon;
gps_position->alt = packet->height_msl;
gps_position->counter_pos_valid++;
gps_position->counter++;
/* Add timestamp to finish the report */
gps_position->timestamp = hrt_absolute_time();
_new_nav_posllh = true;
/* set flag to trigger publishing of new position */
pos_updated = true;
} else {
warnx("NAV_POSLLH: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case NAV_SOL: {
// printf("GOT NAV_SOL MESSAGE\n");
gps_bin_nav_sol_packet_t *packet = (gps_bin_nav_sol_packet_t *) _rx_buffer;
//Check if checksum is valid and the store the gps information
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
gps_position->fix_type = packet->gpsFix;
gps_position->s_variance = packet->sAcc;
gps_position->p_variance = packet->pAcc;
gps_position->counter++;
gps_position->timestamp = hrt_absolute_time();
_new_nav_sol = true;
} else {
warnx("NAV_SOL: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case NAV_DOP: {
// printf("GOT NAV_DOP MESSAGE\n");
gps_bin_nav_dop_packet_t *packet = (gps_bin_nav_dop_packet_t *) _rx_buffer;
//Check if checksum is valid and the store the gps information
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
gps_position->eph = packet->hDOP;
gps_position->epv = packet->vDOP;
gps_position->counter++;
gps_position->timestamp = hrt_absolute_time();
_new_nav_dop = true;
} else {
warnx("NAV_DOP: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case NAV_TIMEUTC: {
// printf("GOT NAV_TIMEUTC MESSAGE\n");
gps_bin_nav_timeutc_packet_t *packet = (gps_bin_nav_timeutc_packet_t *) _rx_buffer;
//Check if checksum is valid and the store the gps information
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
//convert to unix timestamp
struct tm timeinfo;
timeinfo.tm_year = packet->year - 1900;
timeinfo.tm_mon = packet->month - 1;
timeinfo.tm_mday = packet->day;
timeinfo.tm_hour = packet->hour;
timeinfo.tm_min = packet->min;
timeinfo.tm_sec = packet->sec;
time_t epoch = mktime(&timeinfo);
gps_position->time_gps_usec = (uint64_t)epoch * 1000000; //TODO: test this
gps_position->time_gps_usec += (uint64_t)(packet->time_nanoseconds * 1e-3f);
gps_position->counter++;
gps_position->timestamp = hrt_absolute_time();
_new_nav_timeutc = true;
} else {
warnx("NAV_TIMEUTC: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case NAV_SVINFO: {
// printf("GOT NAV_SVINFO MESSAGE\n");
//this is a more complicated message: the length depends on the number of satellites. This number is extracted from the first part of the message
const int length_part1 = 8;
char _rx_buffer_part1[length_part1];
memcpy(_rx_buffer_part1, _rx_buffer, length_part1);
gps_bin_nav_svinfo_part1_packet_t *packet_part1 = (gps_bin_nav_svinfo_part1_packet_t *) _rx_buffer_part1;
//read checksum
const int length_part3 = 2;
char _rx_buffer_part3[length_part3];
memcpy(_rx_buffer_part3, &(_rx_buffer[_rx_count - 1]), length_part3);
gps_bin_nav_svinfo_part3_packet_t *packet_part3 = (gps_bin_nav_svinfo_part3_packet_t *) _rx_buffer_part3;
//Check if checksum is valid and then store the gps information
if (_rx_ck_a == packet_part3->ck_a && _rx_ck_b == packet_part3->ck_b) {
//definitions needed to read numCh elements from the buffer:
const int length_part2 = 12;
gps_bin_nav_svinfo_part2_packet_t *packet_part2;
char _rx_buffer_part2[length_part2]; //for temporal storage
uint8_t satellites_used = 0;
int i;
for (i = 0; i < packet_part1->numCh; i++) { //for each channel
/* Get satellite information from the buffer */
memcpy(_rx_buffer_part2, &(_rx_buffer[length_part1 + i * length_part2]), length_part2);
packet_part2 = (gps_bin_nav_svinfo_part2_packet_t *) _rx_buffer_part2;
/* Write satellite information in the global storage */
gps_position->satellite_prn[i] = packet_part2->svid;
//if satellite information is healthy store the data
uint8_t unhealthy = packet_part2->flags & 1 << 4; //flags is a bitfield
if (!unhealthy) {
if ((packet_part2->flags) & 1) { //flags is a bitfield
gps_position->satellite_used[i] = 1;
satellites_used++;
} else {
gps_position->satellite_used[i] = 0;
}
gps_position->satellite_snr[i] = packet_part2->cno;
gps_position->satellite_elevation[i] = (uint8_t)(packet_part2->elev);
gps_position->satellite_azimuth[i] = (uint8_t)((float)packet_part2->azim * 255.0f / 360.0f);
} else {
gps_position->satellite_used[i] = 0;
gps_position->satellite_snr[i] = 0;
gps_position->satellite_elevation[i] = 0;
gps_position->satellite_azimuth[i] = 0;
}
}
for (i = packet_part1->numCh; i < 20; i++) { //these channels are unused
/* Unused channels have to be set to zero for e.g. MAVLink */
gps_position->satellite_prn[i] = 0;
gps_position->satellite_used[i] = 0;
gps_position->satellite_snr[i] = 0;
gps_position->satellite_elevation[i] = 0;
gps_position->satellite_azimuth[i] = 0;
}
/* set flag if any sat info is available */
if (!packet_part1->numCh > 0) {
gps_position->satellite_info_available = 1;
} else {
gps_position->satellite_info_available = 0;
}
gps_position->satellites_visible = satellites_used++; // visible ~= used but we are interested in the used ones
gps_position->counter++;
gps_position->timestamp = hrt_absolute_time();
// as this message arrives only with 1Hz and is not essential, we don't take it into account for the report
} else {
warnx("NAV_SVINFO: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case NAV_VELNED: {
// printf("GOT NAV_VELNED MESSAGE\n");
gps_bin_nav_velned_packet_t *packet = (gps_bin_nav_velned_packet_t *) _rx_buffer;
//Check if checksum is valid and the store the gps information
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
gps_position->vel = (uint16_t)packet->speed;
gps_position->vel_n = packet->velN / 100.0f;
gps_position->vel_e = packet->velE / 100.0f;
gps_position->vel_d = packet->velD / 100.0f;
gps_position->vel_ned_valid = true;
gps_position->cog = (uint16_t)((float)(packet->heading) * 1e-3f);
gps_position->counter++;
gps_position->timestamp = hrt_absolute_time();
_new_nav_velned = true;
} else {
warnx("NAV_VELNED: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
// case RXM_SVSI: {
// printf("GOT RXM_SVSI MESSAGE\n");
// const int length_part1 = 7;
// char _rx_buffer_part1[length_part1];
// memcpy(_rx_buffer_part1, _rx_buffer, length_part1);
// gps_bin_rxm_svsi_packet_t *packet = (gps_bin_rxm_svsi_packet_t *) _rx_buffer_part1;
//
// //Check if checksum is valid and the store the gps information
// if (_rx_ck_a == _rx_buffer[_rx_count - 1] && _rx_ck_b == _rx_buffer[_rx_count]) {
//
// gps_position->satellites_visible = packet->numVis;
// gps_position->counter++;
// _last_message_timestamps[RXM_SVSI - 1] = hrt_absolute_time();
// ret = 1;
//
// } else {
// warnx("RXM_SVSI: checksum invalid\n");
// }
//
// // Reset state machine to decode next packet
// decodeInit();
// break;
// }
case ACK_ACK: {
// printf("GOT ACK_ACK\n");
gps_bin_ack_ack_packet_t *packet = (gps_bin_ack_ack_packet_t *) _rx_buffer;
//Check if checksum is valid
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
_waiting_for_ack = false;
switch (_config_state) {
case UBX_CONFIG_STATE_PRT:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_PRT)
_config_state = UBX_CONFIG_STATE_PRT_NEW_BAUDRATE;
break;
case UBX_CONFIG_STATE_PRT_NEW_BAUDRATE:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_PRT)
_config_state = UBX_CONFIG_STATE_RATE;
break;
case UBX_CONFIG_STATE_RATE:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_RATE)
_config_state = UBX_CONFIG_STATE_NAV5;
break;
case UBX_CONFIG_STATE_NAV5:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_NAV5)
_config_state = UBX_CONFIG_STATE_MSG_NAV_POSLLH;
break;
case UBX_CONFIG_STATE_MSG_NAV_POSLLH:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_MSG_NAV_TIMEUTC;
break;
case UBX_CONFIG_STATE_MSG_NAV_TIMEUTC:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_MSG_NAV_DOP;
break;
case UBX_CONFIG_STATE_MSG_NAV_DOP:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_MSG_NAV_SVINFO;
break;
case UBX_CONFIG_STATE_MSG_NAV_SVINFO:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_MSG_NAV_SOL;
break;
case UBX_CONFIG_STATE_MSG_NAV_SOL:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_MSG_NAV_VELNED;
break;
case UBX_CONFIG_STATE_MSG_NAV_VELNED:
if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
_config_state = UBX_CONFIG_STATE_CONFIGURED;
/* set the flag to tell the driver that configuration was successful */
config_needed = false;
break;
// case UBX_CONFIG_STATE_MSG_RXM_SVSI:
// if (packet->clsID == UBX_CLASS_CFG && packet->msgID == UBX_MESSAGE_CFG_MSG)
// _config_state = UBX_CONFIG_STATE_CONFIGURED;
// break;
default:
break;
}
} else {
warnx("ACK_ACK: checksum invalid");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
case ACK_NAK: {
// printf("GOT ACK_NAK\n");
gps_bin_ack_nak_packet_t *packet = (gps_bin_ack_nak_packet_t *) _rx_buffer;
//Check if checksum is valid
if (_rx_ck_a == packet->ck_a && _rx_ck_b == packet->ck_b) {
warnx("UBX: Received: Not Acknowledged");
/* configuration obviously not successful */
config_needed = true;
} else {
warnx("ACK_NAK: checksum invalid\n");
}
// Reset state machine to decode next packet
decodeInit();
break;
}
default: //we don't know the message
warnx("UBX: Unknown message received: %d-%d\n",_message_class,_message_id);
decodeInit();
break;
}
} // end if _rx_count high enough
else if (_rx_count < RECV_BUFFER_SIZE) {
_rx_count++;
} else {
warnx("buffer full, restarting");
decodeInit();
config_needed = true;
}
break;
default:
break;
}
/* return 1 when position updates and the remaining packets updated at least once */
if(_new_nav_posllh &&_new_nav_timeutc && _new_nav_dop && _new_nav_sol && _new_nav_velned) {
/* we have received everything, this most probably means that the configuration is fine */
config_needed = false;
/* Reset the flags */
_new_nav_posllh = false;
_new_nav_timeutc = false;
_new_nav_dop = false;
_new_nav_sol = false;
_new_nav_velned = false;
}
return;
}
void
UBX::decodeInit(void)
{
_rx_ck_a = 0;
_rx_ck_b = 0;
_rx_count = 0;
_decode_state = UBX_DECODE_UNINIT;
_message_class = CLASS_UNKNOWN;
_message_id = ID_UNKNOWN;
_payload_size = 0;
}
void
UBX::addByteToChecksum(uint8_t b)
{
_rx_ck_a = _rx_ck_a + b;
_rx_ck_b = _rx_ck_b + _rx_ck_a;
}
void
UBX::addChecksumToMessage(uint8_t* message, const unsigned length)
{
uint8_t ck_a = 0;
uint8_t ck_b = 0;
unsigned i;
for (i = 0; i < length-2; i++) {
ck_a = ck_a + message[i];
ck_b = ck_b + ck_a;
}
/* The checksum is written to the last to bytes of a message */
message[length-2] = ck_a;
message[length-1] = ck_b;
}