/*
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 .
*/
#include
#include "AP_Proximity_TeraRangerTower.h"
#include
#include
#include
#include
extern const AP_HAL::HAL& hal;
/*
The constructor also initialises the proximity sensor. Note that this
constructor is not called until detect() returns true, so we
already know that we should setup the proximity sensor
*/
AP_Proximity_TeraRangerTower::AP_Proximity_TeraRangerTower(
AP_Proximity &_frontend,
AP_Proximity::Proximity_State &_state) :
AP_Proximity_Backend(_frontend, _state)
{
const AP_SerialManager &serial_manager = AP::serialmanager();
uart = serial_manager.find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0);
if (uart != nullptr) {
uart->begin(serial_manager.find_baudrate(AP_SerialManager::SerialProtocol_Lidar360, 0));
}
}
// detect if a TeraRanger Tower proximity sensor is connected by looking for a configured serial port
bool AP_Proximity_TeraRangerTower::detect()
{
AP_HAL::UARTDriver *uart = nullptr;
uart = AP::serialmanager().find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0);
return uart != nullptr;
}
// update the state of the sensor
void AP_Proximity_TeraRangerTower::update(void)
{
if (uart == nullptr) {
return;
}
// process incoming messages
read_sensor_data();
// check for timeout and set health status
if ((_last_distance_received_ms == 0) || (AP_HAL::millis() - _last_distance_received_ms > PROXIMITY_TRTOWER_TIMEOUT_MS)) {
set_status(AP_Proximity::Proximity_NoData);
} else {
set_status(AP_Proximity::Proximity_Good);
}
}
// get maximum and minimum distances (in meters) of primary sensor
float AP_Proximity_TeraRangerTower::distance_max() const
{
return 4.5f;
}
float AP_Proximity_TeraRangerTower::distance_min() const
{
return 0.20f;
}
// check for replies from sensor, returns true if at least one message was processed
bool AP_Proximity_TeraRangerTower::read_sensor_data()
{
if (uart == nullptr) {
return false;
}
uint16_t message_count = 0;
int16_t nbytes = uart->available();
while (nbytes-- > 0) {
char c = uart->read();
if (c == 'T' ) {
buffer_count = 0;
}
buffer[buffer_count++] = c;
// we should always read 19 bytes THxxxxxxxxxxxxxxxxC
if (buffer_count >= 19){
buffer_count = 0;
// check if message has right CRC
if (crc_crc8(buffer, 18) == buffer[18]){
update_sector_data(0, UINT16_VALUE(buffer[2], buffer[3])); // d1
update_sector_data(45, UINT16_VALUE(buffer[16], buffer[17])); // d8
update_sector_data(90, UINT16_VALUE(buffer[14], buffer[15])); // d7
update_sector_data(135, UINT16_VALUE(buffer[12], buffer[13])); // d6
update_sector_data(180, UINT16_VALUE(buffer[10], buffer[11])); // d5
update_sector_data(225, UINT16_VALUE(buffer[8], buffer[9])); // d4
update_sector_data(270, UINT16_VALUE(buffer[6], buffer[7])); // d3
update_sector_data(315, UINT16_VALUE(buffer[4], buffer[5])); // d2
message_count++;
}
}
}
return (message_count > 0);
}
// process reply
void AP_Proximity_TeraRangerTower::update_sector_data(int16_t angle_deg, uint16_t distance_cm)
{
uint8_t sector;
if (convert_angle_to_sector(angle_deg, sector)) {
_angle[sector] = angle_deg;
_distance[sector] = ((float) distance_cm) / 1000;
_distance_valid[sector] = distance_cm != 0xffff;
_last_distance_received_ms = AP_HAL::millis();
// update boundary used for avoidance
update_boundary_for_sector(sector, true);
}
}