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/*
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, see <http://www.gnu.org/licenses/>.
*/
/*
Original C Code by Marvelmind (https://github.com/MarvelmindRobotics/marvelmind.c)
Adapted into Ardupilot by Karthik Desai, Amilcar Lucas
April 2017
*/
#include <AP_HAL/AP_HAL.h>
#include "AP_Beacon_Marvelmind.h"
#define AP_BEACON_MARVELMIND_POSITION_DATAGRAM_ID 0x0001
#define AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_ID 0x0002
#define AP_BEACON_MARVELMIND_DISTANCES_DATAGRAM_ID 0x0004
#define AP_BEACON_MARVELMIND_POSITION_DATAGRAM_HIGHRES_ID 0x0011
#define AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_HIGHRES_ID 0x0012
extern const AP_HAL::HAL& hal;
#define MM_DEBUG_LEVEL 0
#if MM_DEBUG_LEVEL
#include <GCS_MAVLink/GCS.h>
#define Debug(level, fmt, args ...) do { if (level <= MM_DEBUG_LEVEL) { gcs().send_text(MAV_SEVERITY_INFO, fmt, ## args); } } while (0)
#else
#define Debug(level, fmt, args ...)
#endif
AP_Beacon_Marvelmind::AP_Beacon_Marvelmind(AP_Beacon &frontend, AP_SerialManager &serial_manager) :
AP_Beacon_Backend(frontend)
{
uart = serial_manager.find_serial(AP_SerialManager::SerialProtocol_Beacon, 0);
if (uart != nullptr) {
uart->begin(serial_manager.find_baudrate(AP_SerialManager::SerialProtocol_Beacon, 0));
last_update_ms = 0;
parse_state = RECV_HDR; // current state of receive data
num_bytes_in_block_received = 0; // bytes received
data_id = 0;
hedge._have_new_values = false;
hedge.positions_beacons.num_beacons = 0;
hedge.positions_beacons.updated = false;
}
}
//////////////////////////////////////////////////////////////////////////////
// Calculate Modbus CRC16 for array of bytes
// buf: input buffer
// len: size of buffer
// returncode: CRC value
//////////////////////////////////////////////////////////////////////////////
uint16_t AP_Beacon_Marvelmind::calc_crc_modbus(uint8_t *buf, uint16_t len)
{
uint16_t crc = 0xFFFF;
for (uint16_t pos = 0; pos < len; pos++) {
crc ^= (uint16_t) buf[pos]; // XOR byte into least sig. byte of crc
for (uint8_t i = 8; i != 0; i--) { // Loop over each bit
if ((crc & 0x0001) != 0) { // If the LSB is set
crc >>= 1; // Shift right and XOR 0xA001
crc ^= 0xA001;
} else {
// Else LSB is not set
crc >>= 1; // Just shift right
}
}
}
return crc;
}
void AP_Beacon_Marvelmind::process_position_datagram()
{
hedge.cur_position.address = input_buffer[16];
hedge.cur_position.timestamp = input_buffer[5]
| (((uint32_t) input_buffer[6]) << 8)
| (((uint32_t) input_buffer[7]) << 16)
| (((uint32_t) input_buffer[8]) << 24);
const int16_t vx = input_buffer[9] | (((uint16_t) input_buffer[10]) << 8);
hedge.cur_position.x__mm = vx * 10; // centimeters -> millimeters
const int16_t vy = input_buffer[11] | (((uint16_t) input_buffer[12]) << 8);
hedge.cur_position.y__mm = vy * 10; // centimeters -> millimeters
const int16_t vz = input_buffer[13] | (((uint16_t) input_buffer[14]) << 8);
hedge.cur_position.z__mm = vz * 10; // centimeters -> millimeters
hedge.cur_position.high_resolution = false;
hedge._have_new_values = true;
}
void AP_Beacon_Marvelmind::process_position_highres_datagram()
{
hedge.cur_position.address = input_buffer[22];
hedge.cur_position.timestamp = input_buffer[5]
| (((uint32_t) input_buffer[6]) << 8)
| (((uint32_t) input_buffer[7]) << 16)
| (((uint32_t) input_buffer[8]) << 24);
hedge.cur_position.x__mm = input_buffer[9] | (((uint32_t) input_buffer[10]) << 8)
| (((uint32_t) input_buffer[11]) << 16)
| (((uint32_t) input_buffer[12]) << 24);
hedge.cur_position.y__mm = input_buffer[13] | (((uint32_t) input_buffer[14]) << 8)
| (((uint32_t) input_buffer[15]) << 16)
| (((uint32_t) input_buffer[16]) << 24);
hedge.cur_position.z__mm = input_buffer[17] | (((uint32_t) input_buffer[18]) << 8)
| (((uint32_t) input_buffer[19]) << 16)
| (((uint32_t) input_buffer[20]) << 24);
hedge.cur_position.high_resolution = true;
hedge._have_new_values = true;
}
AP_Beacon_Marvelmind::StationaryBeaconPosition* AP_Beacon_Marvelmind::get_or_alloc_beacon(uint8_t address)
{
const uint8_t n_used = hedge.positions_beacons.num_beacons;
for (uint8_t i = 0; i < n_used; i++) {
if (hedge.positions_beacons.beacons[i].address == address) {
return &hedge.positions_beacons.beacons[i];
}
}
if (n_used >= AP_BEACON_MAX_BEACONS) {
return nullptr;
}
hedge.positions_beacons.num_beacons = (n_used + 1);
return &hedge.positions_beacons.beacons[n_used];
}
void AP_Beacon_Marvelmind::process_beacons_positions_datagram()
{
const uint8_t n = input_buffer[5]; // number of beacons in packet
StationaryBeaconPosition *stationary_beacon;
if ((1 + n * 8) != input_buffer[4]) {
Debug(1, "beacon pos lo pkt size %d != %d", input_buffer[4], (1 + n * 8));
return; // incorrect size
}
for (uint8_t i = 0; i < n; i++) {
const uint8_t ofs = 6 + i * 8;
const uint8_t address = input_buffer[ofs];
const int16_t x = input_buffer[ofs + 1]
| (((uint16_t) input_buffer[ofs + 2]) << 8);
const int16_t y = input_buffer[ofs + 3]
| (((uint16_t) input_buffer[ofs + 4]) << 8);
const int16_t z = input_buffer[ofs + 5]
| (((uint16_t) input_buffer[ofs + 6]) << 8);
stationary_beacon = get_or_alloc_beacon(address);
if (stationary_beacon != nullptr) {
stationary_beacon->address = address; //The instance and the address are the same
stationary_beacon->x__mm = x * 10; // centimeters -> millimeters
stationary_beacon->y__mm = y * 10; // centimeters -> millimeters
stationary_beacon->z__mm = z * 10; // centimeters -> millimeters
stationary_beacon->high_resolution = false;
hedge.positions_beacons.updated = true;
}
}
order_stationary_beacons();
}
void AP_Beacon_Marvelmind::process_beacons_positions_highres_datagram()
{
const uint8_t n = input_buffer[5]; // number of beacons in packet
StationaryBeaconPosition *stationary_beacon;
if ((1 + n * 14) != input_buffer[4]) {
Debug(1, "beacon pos hi pkt size %d != %d", input_buffer[4], (1 + n * 14));
return; // incorrect size
}
for (uint8_t i = 0; i < n; i++) {
const uint8_t ofs = 6 + i * 14;
const uint8_t address = input_buffer[ofs];
const int32_t x = input_buffer[ofs + 1]
| (((uint32_t) input_buffer[ofs + 2]) << 8)
| (((uint32_t) input_buffer[ofs + 3]) << 16)
| (((uint32_t) input_buffer[ofs + 4]) << 24);
const int32_t y = input_buffer[ofs + 5]
| (((uint32_t) input_buffer[ofs + 6]) << 8)
| (((uint32_t) input_buffer[ofs + 7]) << 16)
| (((uint32_t) input_buffer[ofs + 8]) << 24);
const int32_t z = input_buffer[ofs + 9]
| (((uint32_t) input_buffer[ofs + 10]) << 8)
| (((uint32_t) input_buffer[ofs + 11]) << 16)
| (((uint32_t) input_buffer[ofs + 12]) << 24);
stationary_beacon = get_or_alloc_beacon(address);
if (stationary_beacon != nullptr) {
stationary_beacon->address = address; //The instance and the address are the same
stationary_beacon->x__mm = x; // millimeters
stationary_beacon->y__mm = y; // millimeters
stationary_beacon->z__mm = z; // millimeters
stationary_beacon->high_resolution = true;
hedge.positions_beacons.updated = true;
}
}
order_stationary_beacons();
}
void AP_Beacon_Marvelmind::process_beacons_distances_datagram()
{
if (32 != input_buffer[4]) {
Debug(1, "beacon dist pkt size %d != 32", input_buffer[4]);
return; // incorrect size
}
bool set = false;
for (uint8_t i = 0; i < hedge.positions_beacons.num_beacons; i++) {
const uint8_t ofs = 6 + i * 6;
const uint8_t address = input_buffer[ofs];
const int8_t instance = find_beacon_instance(address);
if (instance != -1) {
const uint32_t distance = input_buffer[ofs + 1]
| (((uint32_t) input_buffer[ofs + 2]) << 8)
| (((uint32_t) input_buffer[ofs + 3]) << 16)
| (((uint32_t) input_buffer[ofs + 4]) << 24);
hedge.positions_beacons.beacons[instance].distance__m = distance * 0.001f; // millimeters -> meters
set_beacon_distance(instance, hedge.positions_beacons.beacons[instance].distance__m);
set = true;
Debug(2, "Beacon %d is %.2fm", instance, hedge.positions_beacons.beacons[instance].distance__m);
}
}
if (set) {
last_update_ms = AP_HAL::millis();
}
}
int8_t AP_Beacon_Marvelmind::find_beacon_instance(uint8_t address) const
{
for (uint8_t i = 0; i < hedge.positions_beacons.num_beacons; i++) {
if (hedge.positions_beacons.beacons[i].address == address) {
return i;
}
}
return -1;
}
void AP_Beacon_Marvelmind::update(void)
{
if (uart == nullptr) {
return;
}
// read any available characters
int32_t num_bytes_read = uart->available();
uint8_t received_char = 0;
if (num_bytes_read < 0) {
return;
}
while (num_bytes_read-- > 0) {
bool good_byte = false;
received_char = uart->read();
input_buffer[num_bytes_in_block_received] = received_char;
switch (parse_state) {
case RECV_HDR:
switch (num_bytes_in_block_received) {
case 0:
good_byte = (received_char == 0xff);
break;
case 1:
good_byte = (received_char == 0x47);
break;
case 2:
good_byte = true;
break;
case 3:
data_id = (((uint16_t)received_char) << 8) + input_buffer[2];
good_byte = (data_id == AP_BEACON_MARVELMIND_POSITION_DATAGRAM_ID)
|| (data_id == AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_ID)
|| (data_id == AP_BEACON_MARVELMIND_DISTANCES_DATAGRAM_ID)
|| (data_id == AP_BEACON_MARVELMIND_POSITION_DATAGRAM_HIGHRES_ID)
|| (data_id == AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_HIGHRES_ID);
break;
case 4: {
switch (data_id) {
case AP_BEACON_MARVELMIND_POSITION_DATAGRAM_ID: {
good_byte = (received_char == 0x10);
break;
}
case AP_BEACON_MARVELMIND_DISTANCES_DATAGRAM_ID:
case AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_ID:
case AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_HIGHRES_ID:
good_byte = true;
break;
case AP_BEACON_MARVELMIND_POSITION_DATAGRAM_HIGHRES_ID: {
good_byte = (received_char == 0x16);
break;
}
}
if (good_byte) {
parse_state = RECV_DGRAM;
}
break;
}
}
if (good_byte) {
// correct header byte
num_bytes_in_block_received++;
} else {
// ...or incorrect
parse_state = RECV_HDR;
num_bytes_in_block_received = 0;
}
break;
case RECV_DGRAM:
num_bytes_in_block_received++;
if (num_bytes_in_block_received >= 7 + input_buffer[4]) {
// parse dgram
uint16_t block_crc = calc_crc_modbus(input_buffer, num_bytes_in_block_received);
if (block_crc == 0) {
switch (data_id) {
case AP_BEACON_MARVELMIND_POSITION_DATAGRAM_ID:
{
// add to position_buffer
process_position_datagram();
vehicle_position_initialized = true;
set_stationary_beacons_positions();
break;
}
case AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_ID:
{
process_beacons_positions_datagram();
beacon_position_initialized = true;
set_stationary_beacons_positions();
break;
}
case AP_BEACON_MARVELMIND_DISTANCES_DATAGRAM_ID:
{
process_beacons_distances_datagram();
break;
}
case AP_BEACON_MARVELMIND_POSITION_DATAGRAM_HIGHRES_ID:
{
process_position_highres_datagram();
vehicle_position_initialized = true;
set_stationary_beacons_positions();
break;
}
case AP_BEACON_MARVELMIND_POSITIONS_DATAGRAM_HIGHRES_ID:
{
process_beacons_positions_highres_datagram();
beacon_position_initialized = true;
set_stationary_beacons_positions();
break;
}
}
}
// and repeat
parse_state = RECV_HDR;
num_bytes_in_block_received = 0;
}
break;
}
}
}
bool AP_Beacon_Marvelmind::healthy()
{
// healthy if we have parsed a message within the past 300ms
return ((AP_HAL::millis() - last_update_ms) < AP_BEACON_TIMEOUT_MS);
}
void AP_Beacon_Marvelmind::set_stationary_beacons_positions()
{
bool set = false;
if (vehicle_position_initialized && beacon_position_initialized) {
if (hedge._have_new_values) {
vehicle_position_NED__m = Vector3f(hedge.cur_position.y__mm * 0.001f,
hedge.cur_position.x__mm * 0.001f,
-hedge.cur_position.z__mm * 0.001f); //Transform Marvelmind ENU to Ardupilot NED
//TODO: Calculate Accuracy of the received signal. Marvelmind *advertises* +/- 2cms
// But we are conservative here and use 20cm instead (until MM provides us with a proper accuracy value)
set_vehicle_position(vehicle_position_NED__m, 0.2f);
set = true;
Debug(2,
"Hedge is at N%.2f, E%.2f, D%.2f",
vehicle_position_NED__m[0],
vehicle_position_NED__m[1],
vehicle_position_NED__m[2]);
}
hedge._have_new_values = false;
for (uint8_t i = 0; i < hedge.positions_beacons.num_beacons; ++i) {
if (hedge.positions_beacons.updated) {
beacon_position_NED__m[i] = Vector3f(hedge.positions_beacons.beacons[i].y__mm * 0.001f,
hedge.positions_beacons.beacons[i].x__mm * 0.001f,
-hedge.positions_beacons.beacons[i].z__mm * 0.001f); //Transform Marvelmind ENU to Ardupilot NED
set_beacon_position(i, beacon_position_NED__m[i]);
set = true;
Debug(2,
"Beacon %d is at N%.2f, E%.2f, D%.2f",
i,
beacon_position_NED__m[i][0],
beacon_position_NED__m[i][1],
beacon_position_NED__m[i][2]);
}
}
hedge.positions_beacons.updated = false;
}
if (set) {
last_update_ms = AP_HAL::millis();
}
}
void AP_Beacon_Marvelmind::order_stationary_beacons()
{
if (hedge.positions_beacons.updated) {
bool swapped = false;
uint8_t j = hedge.positions_beacons.num_beacons;
do
{
swapped = false;
StationaryBeaconPosition beacon_to_swap;
for (uint8_t i = 1; i < j; i++) {
if (hedge.positions_beacons.beacons[i-1].address > hedge.positions_beacons.beacons[i].address) {
beacon_to_swap = hedge.positions_beacons.beacons[i];
hedge.positions_beacons.beacons[i] = hedge.positions_beacons.beacons[i-1];
hedge.positions_beacons.beacons[i-1] = beacon_to_swap;
swapped = true;
}
}
j--;
} while(swapped);
}
}
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