ardupilot/libraries/AP_Proximity/AP_Proximity_LightWareSF45B...

207 lines
7.9 KiB
C++

/*
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/>.
The Lightware SF45B serial interface is described on this wiki page
http://support.lightware.co.za/sf45/#/commands
*/
#include "AP_Proximity_config.h"
#if AP_PROXIMITY_LIGHTWARE_SF45B_ENABLED
#include "AP_Proximity_LightWareSF45B.h"
#include <AP_Common/AP_Common.h>
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/utility/sparse-endian.h>
extern const AP_HAL::HAL& hal;
static const uint32_t PROXIMITY_SF45B_TIMEOUT_MS = 200;
static const uint32_t PROXIMITY_SF45B_REINIT_INTERVAL_MS = 5000; // re-initialise sensor after this many milliseconds
static const float PROXIMITY_SF45B_COMBINE_READINGS_DEG = 5.0f; // combine readings from within this many degrees to improve efficiency
static const uint32_t PROXIMITY_SF45B_STREAM_DISTANCE_DATA_CM = 5;
static const uint8_t PROXIMITY_SF45B_DESIRED_UPDATE_RATE = 6; // 1:48hz, 2:55hz, 3:64hz, 4:77hz, 5:97hz, 6:129hz, 7:194hz, 8:388hz
static const uint32_t PROXIMITY_SF45B_DESIRED_FIELDS = ((uint32_t)1 << 0 | (uint32_t)1 << 8); // first return (unfiltered), yaw angle
static const uint16_t PROXIMITY_SF45B_DESIRED_FIELD_COUNT = 2; // DISTANCE_DATA_CM message should contain two fields
// update the state of the sensor
void AP_Proximity_LightWareSF45B::update(void)
{
if (_uart == nullptr) {
return;
}
// initialise sensor if necessary
initialise();
// process incoming messages
process_replies();
// check for timeout and set health status
if ((_last_distance_received_ms == 0) || ((AP_HAL::millis() - _last_distance_received_ms) > PROXIMITY_SF45B_TIMEOUT_MS)) {
set_status(AP_Proximity::Status::NoData);
} else {
set_status(AP_Proximity::Status::Good);
}
}
// initialise sensor
void AP_Proximity_LightWareSF45B::initialise()
{
// check sensor is configured correctly
_init_complete = (_sensor_state.stream_data_type == PROXIMITY_SF45B_STREAM_DISTANCE_DATA_CM) &&
(_sensor_state.update_rate == PROXIMITY_SF45B_DESIRED_UPDATE_RATE) &&
(_sensor_state.streaming_fields == PROXIMITY_SF45B_DESIRED_FIELDS);
// exit if initialisation requests have been sent within the last few seconds
uint32_t now_ms = AP_HAL::millis();
if ((now_ms - _last_init_ms) < PROXIMITY_SF45B_REINIT_INTERVAL_MS) {
return;
}
_last_init_ms = now_ms;
// request stream rate and contents
request_stream_start();
}
// request start of streaming of distances
void AP_Proximity_LightWareSF45B::request_stream_start()
{
// request output rate
send_message((uint8_t)MessageID::UPDATE_RATE, true, &PROXIMITY_SF45B_DESIRED_UPDATE_RATE, sizeof(PROXIMITY_SF45B_DESIRED_UPDATE_RATE));
// request first return (unfiltered), and yaw angle
send_message((uint8_t)MessageID::DISTANCE_OUTPUT, true, (const uint8_t*)&PROXIMITY_SF45B_DESIRED_FIELDS, sizeof(PROXIMITY_SF45B_DESIRED_FIELDS));
// request start streaming of DISTANCE_DATA_CM messages
send_message((uint8_t)MessageID::STREAM, true, (const uint8_t*)&PROXIMITY_SF45B_STREAM_DISTANCE_DATA_CM, sizeof(PROXIMITY_SF45B_STREAM_DISTANCE_DATA_CM));
}
// check for replies from sensor
void AP_Proximity_LightWareSF45B::process_replies()
{
if (_uart == nullptr) {
return;
}
// process up to 1K of characters per iteration
uint32_t nbytes = MIN(_uart->available(), 1024U);
while (nbytes-- > 0) {
const int16_t r = _uart->read();
if ((r < 0) || (r > 0xFF)) {
continue;
}
if (parse_byte((uint8_t)r)) {
process_message();
}
}
}
// process the latest message held in the _msg structure
void AP_Proximity_LightWareSF45B::process_message()
{
// process payload
switch ((MessageID)_msg.msgid) {
case MessageID::DISTANCE_OUTPUT:
if (_payload_recv == sizeof(uint32_t)) {
_sensor_state.streaming_fields = UINT32_VALUE(_msg.payload[3], _msg.payload[2], _msg.payload[1], _msg.payload[0]);
}
break;
case MessageID::STREAM:
if (_payload_recv == sizeof(uint32_t)) {
_sensor_state.stream_data_type = UINT32_VALUE(_msg.payload[3], _msg.payload[2], _msg.payload[1], _msg.payload[0]);
}
break;
case MessageID::UPDATE_RATE:
if (_payload_recv == 1) {
_sensor_state.update_rate = _msg.payload[0];
}
break;
case MessageID::DISTANCE_DATA_CM: {
// ignore distance messages until initialisation is complete
if (!_init_complete || (_payload_recv != (PROXIMITY_SF45B_DESIRED_FIELD_COUNT * 2))) {
break;
}
_last_distance_received_ms = AP_HAL::millis();
const float distance_m = _distance_filt.apply((int16_t)UINT16_VALUE(_msg.payload[1], _msg.payload[0])) * 0.01f;
const float angle_deg = correct_angle_for_orientation((int16_t)UINT16_VALUE(_msg.payload[3], _msg.payload[2]) * 0.01f);
// if distance is from a new face then update distance, angle and boundary for previous face
// get face from 3D boundary based on yaw angle to the object
const AP_Proximity_Boundary_3D::Face face = frontend.boundary.get_face(angle_deg);
if (face != _face) {
if (_face_distance_valid) {
frontend.boundary.set_face_attributes(_face, _face_yaw_deg, _face_distance, state.instance);
} else {
// mark previous face invalid
frontend.boundary.reset_face(_face, state.instance);
}
// record updated face
_face = face;
_face_yaw_deg = 0;
_face_distance = INT16_MAX;
_face_distance_valid = false;
}
// if distance is from a new minisector then update obstacle database using angle and distance from previous minisector
const uint8_t minisector = convert_angle_to_minisector(angle_deg);
if (minisector != _minisector) {
if ((_minisector != UINT8_MAX) && _minisector_distance_valid) {
database_push(_minisector_angle, _minisector_distance);
}
// init mini sector
_minisector = minisector;
_minisector_angle = 0;
_minisector_distance = INT16_MAX;
_minisector_distance_valid = false;
}
// check reading is valid
if (!ignore_reading(angle_deg, distance_m) && (distance_m >= distance_min()) && (distance_m <= distance_max())) {
// update shortest distance for this face
if (!_face_distance_valid || (distance_m < _face_distance)) {
_face_yaw_deg = angle_deg;
_face_distance = distance_m;
_face_distance_valid = true;
}
// update shortest distance for this mini sector
if (distance_m < _minisector_distance) {
_minisector_angle = angle_deg;
_minisector_distance = distance_m;
_minisector_distance_valid = true;
}
}
break;
}
default:
// ignore unsupported messages
break;
}
}
// convert an angle (in degrees) to a mini sector number
uint8_t AP_Proximity_LightWareSF45B::convert_angle_to_minisector(float angle_deg) const
{
return wrap_360(angle_deg + (PROXIMITY_SF45B_COMBINE_READINGS_DEG * 0.5f)) / PROXIMITY_SF45B_COMBINE_READINGS_DEG;
}
#endif // AP_PROXIMITY_LIGHTWARE_SF45B_ENABLED