ardupilot/libraries/AP_TemperatureSensor/AP_TemperatureSensor_TSYS01...

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/*
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_TemperatureSensor_TSYS01.h"
#if AP_TEMPERATURE_SENSOR_TSYS01_ENABLED
#include <utility>
#include <stdio.h>
#include <AP_HAL/I2CDevice.h>
#include <AP_Math/AP_Math.h>
#ifndef AP_TEMPERATURE_SENSOR_TSYS01_ENFORCE_KNOWN_VALID_I2C_ADDRESS
#define AP_TEMPERATURE_SENSOR_TSYS01_ENFORCE_KNOWN_VALID_I2C_ADDRESS 1
#endif
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;
void AP_TemperatureSensor_TSYS01::init()
{
constexpr char name[] = "TSYS01";
#if AP_TEMPERATURE_SENSOR_TSYS01_ENFORCE_KNOWN_VALID_I2C_ADDRESS
// I2C Address: Default to using TSYS01_ADDR_CSB0 & Check I2C Address is Correct
if ((_params.bus_address != TSYS01_ADDR_CSB0) && (_params.bus_address != TSYS01_ADDR_CSB1)) {
printf("%s wrong I2C addr of 0x%2X, setting to 0x%2X", name, (unsigned)_params.bus_address.get(), (unsigned)TSYS01_ADDR_CSB0);
_params.bus_address.set(TSYS01_ADDR_CSB0);
}
#endif
_dev = std::move(hal.i2c_mgr->get_device(_params.bus, _params.bus_address));
if (!_dev) {
printf("%s device is null!", name);
return;
}
WITH_SEMAPHORE(_dev->get_semaphore());
_dev->set_retries(10);
// reset
if (!_dev->transfer(&TSYS01_CMD_RESET, 1, nullptr, 0)) {
printf("%s reset failed", name);
return;
}
hal.scheduler->delay(4);
if (!read_prom()) {
printf("%s prom read failed", name);
return;
}
start_next_sample();
// lower retries for run
_dev->set_retries(3);
/* Request 20Hz update */
// Max conversion time is 9.04 ms
_dev->register_periodic_callback(50 * AP_USEC_PER_MSEC,
FUNCTOR_BIND_MEMBER(&AP_TemperatureSensor_TSYS01::_timer, void));
}
// 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 AP_TemperatureSensor_TSYS01::read_prom()
{
bool success = false;
for (uint8_t i = 0; i < ARRAY_SIZE(_k); i++) {
// Read only the prom values that we use
_k[i] = read_prom_word(ARRAY_SIZE(_k)-i);
success |= (_k[i] != 0);
}
return success;
}
// Borrowed from MS Baro driver
uint16_t AP_TemperatureSensor_TSYS01::read_prom_word(const uint8_t word) const
{
const uint8_t reg = TSYS01_CMD_READ_PROM + (word << 1);
uint8_t val[2];
if (!_dev->transfer(&reg, 1, val, 2)) {
return 0;
}
return UINT16_VALUE(val[0], val[1]);
}
uint32_t AP_TemperatureSensor_TSYS01::read_adc() const
{
uint8_t val[3];
if (!_dev->transfer(&TSYS01_CMD_READ_ADC, 1, val, 3)) {
return 0;
}
return UINT32_VALUE(0,val[0],val[1],val[2]);
}
void AP_TemperatureSensor_TSYS01::_timer(void)
{
const uint32_t adc = read_adc();
if (adc != 0) {
const float temp = calculate(adc);
set_temperature(temp);
}
start_next_sample();
}
void AP_TemperatureSensor_TSYS01::start_next_sample()
{
_dev->transfer(&TSYS01_CMD_CONVERT, 1, nullptr, 0);
}
float AP_TemperatureSensor_TSYS01::calculate(const uint32_t adc) const
{
const float adc16 = adc/256;
const float 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);
return temperature;
}
#endif // AP_TEMPERATURE_SENSOR_TSYS01_ENABLED