ardupilot/libraries/AP_TemperatureSensor/TSYS01.cpp

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#include "TSYS01.h"
#include <utility>
#include <stdio.h>
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/I2CDevice.h>
#include <AP_Math/AP_Math.h>
extern const AP_HAL::HAL &hal;
static const uint8_t TSYS01_CMD_RESET = 0x1E;
static const uint8_t TSYS01_CMD_READ_PROM = 0xA0;
static const uint8_t TSYS01_CMD_CONVERT = 0x40;
static const uint8_t TSYS01_CMD_READ_ADC = 0x00;
bool TSYS01::init(uint8_t bus)
{
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
return false;
#endif
_dev = std::move(hal.i2c_mgr->get_device(bus, TSYS01_ADDR));
if (!_dev) {
printf("TSYS01 device is null!");
return false;
}
_dev->get_semaphore()->take_blocking();
_dev->set_retries(10);
if (!_reset()) {
printf("TSYS01 reset failed");
_dev->get_semaphore()->give();
return false;
}
hal.scheduler->delay(4);
if (!_read_prom()) {
printf("TSYS01 prom read failed");
_dev->get_semaphore()->give();
return false;
}
_convert();
// lower retries for run
_dev->set_retries(3);
_dev->get_semaphore()->give();
/* Request 20Hz update */
// Max conversion time is 9.04 ms
_dev->register_periodic_callback(50 * AP_USEC_PER_MSEC,
FUNCTOR_BIND_MEMBER(&TSYS01::_timer, void));
return true;
}
bool TSYS01::_reset()
{
return _dev->transfer(&TSYS01_CMD_RESET, 1, nullptr, 0);
}
// Register map
// prom word Address
// 0 0xA0 -> unused
// 1 0xA2 -> _k[4]
// 2 0xA4 -> _k[3]
// 3 0xA6 -> _k[2]
// 4 0xA8 -> _k[1]
// 5 0xAA -> _k[0]
// 6 0xAC -> unused
// 7 0xAE -> unused
bool TSYS01::_read_prom()
{
bool success = false;
for (int i = 0; i < 5; i++) {
// Read only the prom values that we use
_k[i] = _read_prom_word(5-i);
success |= _k[i] != 0;
}
return success;
}
// Borrowed from MS Baro driver
uint16_t TSYS01::_read_prom_word(uint8_t word)
{
const uint8_t reg = TSYS01_CMD_READ_PROM + (word << 1);
uint8_t val[2];
if (!_dev->transfer(&reg, 1, val, 2)) {
return 0;
}
return (val[0] << 8) | val[1];
}
bool TSYS01::_convert()
{
return _dev->transfer(&TSYS01_CMD_CONVERT, 1, nullptr, 0);
}
uint32_t TSYS01::_read_adc()
{
uint8_t val[3];
if (!_dev->transfer(&TSYS01_CMD_READ_ADC, 1, val, 3)) {
return 0;
}
return (val[0] << 16) | (val[1] << 8) | val[2];
}
void TSYS01::_timer(void)
{
uint32_t adc = _read_adc();
_healthy = adc != 0;
if (_healthy) {
_calculate(adc);
} else {
_temperature = 0;
}
//printf("\nTemperature: %.2lf C", _temperature);
_convert();
}
void TSYS01::_calculate(uint32_t adc)
{
float adc16 = adc/256;
_temperature =
-2 * _k[4] * powf(10, -21) * powf(adc16, 4) +
4 * _k[3] * powf(10, -16) * powf(adc16, 3) +
-2 * _k[2] * powf(10, -11) * powf(adc16, 2) +
1 * _k[1] * powf(10, -6) * adc16 +
-1.5 * _k[0] * powf(10, -2);
}