/*
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_LightWareSF40C_v09.h"
#include
#include
extern const AP_HAL::HAL& hal;
// update the state of the sensor
void AP_Proximity_LightWareSF40C_v09::update(void)
{
if (_uart == nullptr) {
return;
}
// initialise sensor if necessary
bool initialised = initialise();
// process incoming messages
check_for_reply();
// request new data from sensor
if (initialised) {
request_new_data();
}
// check for timeout and set health status
if ((_last_distance_received_ms == 0) || (AP_HAL::millis() - _last_distance_received_ms > PROXIMITY_SF40C_TIMEOUT_MS)) {
set_status(AP_Proximity::Status::NoData);
} else {
set_status(AP_Proximity::Status::Good);
}
}
// get maximum and minimum distances (in meters) of primary sensor
float AP_Proximity_LightWareSF40C_v09::distance_max() const
{
return 100.0f;
}
float AP_Proximity_LightWareSF40C_v09::distance_min() const
{
return 0.20f;
}
// initialise sensor (returns true if sensor is successfully initialised)
bool AP_Proximity_LightWareSF40C_v09::initialise()
{
// set motor direction once per second
if (_motor_direction > 1) {
if ((_last_request_ms == 0) || AP_HAL::millis() - _last_request_ms > 1000) {
set_motor_direction();
}
}
// set forward direction once per second
if (_forward_direction != frontend.get_yaw_correction(state.instance)) {
if ((_last_request_ms == 0) || AP_HAL::millis() - _last_request_ms > 1000) {
set_forward_direction();
}
}
// request motors turn on once per second
if (_motor_speed == 0) {
if ((_last_request_ms == 0) || AP_HAL::millis() - _last_request_ms > 1000) {
set_motor_speed(true);
}
return false;
}
// initialise sectors
init_boundary();
return true;
}
// set speed of rotating motor
void AP_Proximity_LightWareSF40C_v09::set_motor_speed(bool on_off)
{
// exit immediately if no uart
if (_uart == nullptr) {
return;
}
// set motor update speed
if (on_off) {
_uart->write("#MBS,3\r\n"); // send request to spin motor at 4.5hz
} else {
_uart->write("#MBS,0\r\n"); // send request to stop motor
}
// request update motor speed
_uart->write("?MBS\r\n");
_last_request_type = RequestType_MotorSpeed;
_last_request_ms = AP_HAL::millis();
}
// set spin direction of motor
void AP_Proximity_LightWareSF40C_v09::set_motor_direction()
{
// exit immediately if no uart
if (_uart == nullptr) {
return;
}
// set motor update speed
if (frontend.get_orientation(state.instance) == 0) {
_uart->write("#MBD,0\r\n"); // spin clockwise
} else {
_uart->write("#MBD,1\r\n"); // spin counter clockwise
}
// request update on motor direction
_uart->write("?MBD\r\n");
_last_request_type = RequestType_MotorDirection;
_last_request_ms = AP_HAL::millis();
}
// set forward direction (to allow rotating lidar)
void AP_Proximity_LightWareSF40C_v09::set_forward_direction()
{
// exit immediately if no uart
if (_uart == nullptr) {
return;
}
// set forward direction
char request_str[15];
int16_t yaw_corr = frontend.get_yaw_correction(state.instance);
yaw_corr = constrain_int16(yaw_corr, -999, 999);
snprintf(request_str, sizeof(request_str), "#MBF,%d\r\n", yaw_corr);
_uart->write(request_str);
// request update on motor direction
_uart->write("?MBF\r\n");
_last_request_type = RequestType_ForwardDirection;
_last_request_ms = AP_HAL::millis();
}
// request new data if required
void AP_Proximity_LightWareSF40C_v09::request_new_data()
{
if (_uart == nullptr) {
return;
}
// after timeout assume no reply will ever come
uint32_t now = AP_HAL::millis();
if ((_last_request_type != RequestType_None) && ((now - _last_request_ms) > PROXIMITY_SF40C_TIMEOUT_MS)) {
_last_request_type = RequestType_None;
_last_request_ms = 0;
}
// if we are not waiting for a reply, ask for something
if (_last_request_type == RequestType_None) {
_request_count++;
if (_request_count >= 5) {
send_request_for_health();
_request_count = 0;
} else {
// request new distance measurement
send_request_for_distance();
}
_last_request_ms = now;
}
}
// send request for sensor health
void AP_Proximity_LightWareSF40C_v09::send_request_for_health()
{
if (_uart == nullptr) {
return;
}
_uart->write("?GS\r\n");
_last_request_type = RequestType_Health;
_last_request_ms = AP_HAL::millis();
}
// send request for distance from the next sector
bool AP_Proximity_LightWareSF40C_v09::send_request_for_distance()
{
if (_uart == nullptr) {
return false;
}
// increment sector
_last_sector++;
if (_last_sector >= PROXIMITY_NUM_SECTORS) {
_last_sector = 0;
}
// prepare request
char request_str[16];
snprintf(request_str, sizeof(request_str), "?TS,%u,%u\r\n",
(unsigned int)PROXIMITY_SECTOR_WIDTH_DEG,
_sector_middle_deg[_last_sector]);
_uart->write(request_str);
// record request for distance
_last_request_type = RequestType_DistanceMeasurement;
_last_request_ms = AP_HAL::millis();
return true;
}
// check for replies from sensor, returns true if at least one message was processed
bool AP_Proximity_LightWareSF40C_v09::check_for_reply()
{
if (_uart == nullptr) {
return false;
}
// read any available lines from the lidar
// if CR (i.e. \r), LF (\n) it means we have received a full packet so send for processing
// lines starting with # are ignored because this is the echo of a set-motor request which has no reply
// lines starting with ? are the echo back of our distance request followed by the sensed distance
// distance data appears after a
// distance data is comma separated so we put into separate elements (i.e. angle,distance)
uint16_t count = 0;
int16_t nbytes = _uart->available();
while (nbytes-- > 0) {
char c = _uart->read();
// check for end of packet
if (c == '\r' || c == '\n') {
if ((element_len[0] > 0)) {
if (process_reply()) {
count++;
}
}
// clear buffers after processing
clear_buffers();
ignore_reply = false;
wait_for_space = false;
// if message starts with # ignore it
} else if (c == '#' || ignore_reply) {
ignore_reply = true;
// if waiting for
} else if (c == '?') {
wait_for_space = true;
} else if (wait_for_space) {
if (c == ' ') {
wait_for_space = false;
}
// if comma, move onto filling in 2nd element
} else if (c == ',') {
if ((element_num == 0) && (element_len[0] > 0)) {
element_num++;
} else {
// don't support 3rd element so clear buffers
clear_buffers();
ignore_reply = true;
}
// if part of a number, add to element buffer
} else if (isdigit(c) || c == '.' || c == '-') {
element_buf[element_num][element_len[element_num]] = c;
element_len[element_num]++;
if (element_len[element_num] >= sizeof(element_buf[element_num])-1) {
// too long, discard the line
clear_buffers();
ignore_reply = true;
}
}
}
return (count > 0);
}
// process reply
bool AP_Proximity_LightWareSF40C_v09::process_reply()
{
if (_uart == nullptr) {
return false;
}
bool success = false;
switch (_last_request_type) {
case RequestType_None:
break;
case RequestType_Health:
// expect result in the form "0xhhhh"
if (element_len[0] > 0) {
long int result = strtol(element_buf[0], nullptr, 16);
if (result > 0) {
_sensor_status.value = result;
success = true;
}
}
break;
case RequestType_MotorSpeed:
_motor_speed = atoi(element_buf[0]);
success = true;
break;
case RequestType_MotorDirection:
_motor_direction = atoi(element_buf[0]);
success = true;
break;
case RequestType_ForwardDirection:
_forward_direction = atoi(element_buf[0]);
success = true;
break;
case RequestType_DistanceMeasurement:
{
float angle_deg = strtof(element_buf[0], NULL);
float distance_m = strtof(element_buf[1], NULL);
if (!ignore_reading(angle_deg)) {
const uint8_t sector = convert_angle_to_sector(angle_deg);
_angle[sector] = angle_deg;
_distance[sector] = distance_m;
_distance_valid[sector] = is_positive(distance_m);
_last_distance_received_ms = AP_HAL::millis();
success = true;
// update boundary used for avoidance
update_boundary_for_sector(sector, true);
}
break;
}
default:
break;
}
// mark request as cleared
if (success) {
_last_request_type = RequestType_None;
}
return success;
}
// clear buffers ahead of processing next message
void AP_Proximity_LightWareSF40C_v09::clear_buffers()
{
element_len[0] = 0;
element_len[1] = 0;
element_num = 0;
memset(element_buf, 0, sizeof(element_buf));
}