ardupilot/libraries/AP_TemperatureSensor/AP_TemperatureSensor_Analog...

98 lines
3.9 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_TemperatureSensor_config.h"
#if AP_TEMPERATURE_SENSOR_ANALOG_ENABLED
#include "AP_TemperatureSensor_Analog.h"
extern const AP_HAL::HAL &hal;
const AP_Param::GroupInfo AP_TemperatureSensor_Analog::var_info[] = {
// @Param: PIN
// @DisplayName: Temperature sensor analog voltage sensing pin
// @Description: Sets the analog input pin that should be used for temprature monitoring. Values for some autopilots are given as examples. Search wiki for "Analog pins".
// @Values: -1:Disabled, 2:Pixhawk/Pixracer/Navio2/Pixhawk2_PM1, 5:Navigator, 13:Pixhawk2_PM2/CubeOrange_PM2, 14:CubeOrange, 16:Durandal, 100:PX4-v1
// @User: Standard
AP_GROUPINFO("PIN", 1, AP_TemperatureSensor_Analog, _pin, -1),
// @Param: A0
// @DisplayName: Temperature sensor analog 0th polynomial coefficient
// @Description: a0 in polynomial of form temperature in deg = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
AP_GROUPINFO("A0", 2, AP_TemperatureSensor_Analog, _a[0], 0),
// @Param: A1
// @DisplayName: Temperature sensor analog 1st polynomial coefficient
// @Description: a1 in polynomial of form temperature in deg = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
AP_GROUPINFO("A1", 3, AP_TemperatureSensor_Analog, _a[1], 0),
// @Param: A2
// @DisplayName: Temperature sensor analog 2nd polynomial coefficient
// @Description: a2 in polynomial of form temperature in deg = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
AP_GROUPINFO("A2", 4, AP_TemperatureSensor_Analog, _a[2], 0),
// @Param: A3
// @DisplayName: Temperature sensor analog 3rd polynomial coefficient
// @Description: a3 in polynomial of form temperature in deg = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
AP_GROUPINFO("A3", 5, AP_TemperatureSensor_Analog, _a[3], 0),
// @Param: A4
// @DisplayName: Temperature sensor analog 4th polynomial coefficient
// @Description: a4 in polynomial of form temperature in deg = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
AP_GROUPINFO("A4", 6, AP_TemperatureSensor_Analog, _a[4], 0),
AP_GROUPEND
};
AP_TemperatureSensor_Analog::AP_TemperatureSensor_Analog(AP_TemperatureSensor &front,
AP_TemperatureSensor::TemperatureSensor_State &state,
AP_TemperatureSensor_Params &params) :
AP_TemperatureSensor_Backend(front, state, params)
{
AP_Param::setup_object_defaults(this, var_info);
_state.var_info = var_info;
_analog_source = hal.analogin->channel(_pin);
}
// Update function called at 5Hz
void AP_TemperatureSensor_Analog::update()
{
if ((_analog_source == nullptr) || !_analog_source->set_pin(_pin)) {
// Invalid pln
return;
}
// Use ratiometric voltage, measured voltage is relative to supply
const float voltage = _analog_source->voltage_average_ratiometric();
// Evaluate polynomial
// temperature (deg) = a0 + a1*voltage + a2*voltage^2 + a3*voltage^3 + a4*voltage^4
float temp = 0.0;
float poly = 1.0;
for (uint8_t i = 0; i < ARRAY_SIZE(_a); i++) {
temp += _a[i] * poly;
poly *= voltage;
}
// update state
set_temperature(temp);
}
#endif // AP_TEMPERATURE_SENSOR_ANALOG_ENABLED