mirror of https://github.com/ArduPilot/ardupilot
73 lines
1.9 KiB
C++
73 lines
1.9 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/>.
|
|
*/
|
|
|
|
#include "AP_RangeFinder_GYUS42v2.h"
|
|
|
|
#if AP_RANGEFINDER_GYUS42V2_ENABLED
|
|
|
|
bool AP_RangeFinder_GYUS42v2::find_signature_in_buffer(uint8_t start)
|
|
{
|
|
for (uint8_t i=start; i<buffer_used; i++) {
|
|
if (buffer[i] == 0x5A) {
|
|
memmove(&buffer[0], &buffer[i], buffer_used-i);
|
|
buffer_used -= i;
|
|
return true;
|
|
}
|
|
}
|
|
// header byte not in buffer
|
|
buffer_used = 0;
|
|
return false;
|
|
}
|
|
|
|
// get_reading - read a value from the sensor
|
|
bool AP_RangeFinder_GYUS42v2::get_reading(float &reading_m)
|
|
{
|
|
if (uart == nullptr) {
|
|
return false;
|
|
}
|
|
|
|
const uint8_t num_read = uart->read(&buffer[buffer_used], ARRAY_SIZE(buffer)-buffer_used);
|
|
buffer_used += num_read;
|
|
|
|
if (buffer_used == 0) {
|
|
return false;
|
|
}
|
|
|
|
if (buffer[0] != 0x5A &&
|
|
!find_signature_in_buffer(1)) {
|
|
return false;
|
|
}
|
|
|
|
if (buffer_used < ARRAY_SIZE(buffer)) {
|
|
return false;
|
|
}
|
|
|
|
uint8_t sum = 0;
|
|
for (uint8_t i=0; i<6; i++) {
|
|
sum += buffer[i];
|
|
}
|
|
if (buffer[6] != sum) {
|
|
find_signature_in_buffer(1);
|
|
return false;
|
|
}
|
|
|
|
reading_m = (buffer[4] << 8 | buffer[5]) * 0.01f;
|
|
buffer_used = 0;
|
|
|
|
return true;
|
|
}
|
|
|
|
#endif // AP_RANGEFINDER_GYUS42V2_ENABLED
|