LibrePilot/flight/modules/Temperature/temperature.c

/**
 ******************************************************************************
 * @addtogroup OpenPilotModules OpenPilot Modules
 * @{
 * @addtogroup TemperatureModule Temperature Module
 * @brief Measures the temperature from external sensor.
 * Updates the TemperatureState object
 * @{
 *
 * @file       temperature.c
 * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2019.
 *             The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      Module to read the temperature periodically from NTC or LM35 sensors.
 *
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * 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, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/**
 * Output object: TemperatureState
 *
 * This module will periodically generate information on the temperature state.
 *
 * UAVObjects are automatically generated by the UAVObjectGenerator from
 * the object definition XML file.
 *
 * Modules have no API, all communication to other modules is done through UAVObjects.
 * However modules may use the API exposed by shared libraries.
 * See the OpenPilot wiki for more details.
 * http://www.openpilot.org/OpenPilot_Application_Architecture
 *
 */

#include "openpilot.h"

#include "temperaturestate.h"
#include "temperaturesettings.h"
#include "hwsettings.h"

//
// Configuration
//
#define SAMPLE_PERIOD_MS             500

#ifndef PIOS_ADC_NTCTEMPERATURE_PIN
#define PIOS_ADC_NTCTEMPERATURE_PIN  -1
#endif

#ifndef PIOS_ADC_LM35TEMPERATURE_PIN
#define PIOS_ADC_LM35TEMPERATURE_PIN -1
#endif

static int8_t ntcTemperatureADCPin  = PIOS_ADC_NTCTEMPERATURE_PIN; // ADC pin for temperature (ntc)
static int8_t lm35TemperatureADCPin = PIOS_ADC_LM35TEMPERATURE_PIN; // ADC pin for temperature (lm35)

// Private functions
static void onTimer(UAVObjEvent *ev);

/**
 * Initialise the module, called on startup
 * \returns 0 on success or -1 if initialisation failed
 */
int32_t TemperatureInitialize(void)
{
    bool temperatureEnabled;

    HwSettingsOptionalModulesData optionalModules;

    HwSettingsOptionalModulesGet(&optionalModules);

#ifdef MODULE_TEMPERATURE_BUILTIN
    temperatureEnabled = true;
    optionalModules.Temperature = HWSETTINGS_OPTIONALMODULES_ENABLED;
    HwSettingsOptionalModulesSet(&optionalModules);
#else
    if (optionalModules.Temperature == HWSETTINGS_OPTIONALMODULES_ENABLED) {
        temperatureEnabled = true;
    } else {
        temperatureEnabled = false;
    }
#endif

    uint8_t adcRouting[HWSETTINGS_ADCROUTING_NUMELEM];
    HwSettingsADCRoutingArrayGet(adcRouting);

    // Determine if the temperature sensors are routed to ADC pins
    for (int i = 0; i < HWSETTINGS_ADCROUTING_NUMELEM; i++) {
        if (adcRouting[i] == HWSETTINGS_ADCROUTING_NTCTEMPERATURE) {
            ntcTemperatureADCPin = i;
        }
        if (adcRouting[i] == HWSETTINGS_ADCROUTING_LM35TEMPERATURE) {
            lm35TemperatureADCPin = i;
        }
    }

    // Don't enable module if no ADC pins are routed to the sensors
    if (ntcTemperatureADCPin < 0 && lm35TemperatureADCPin < 0) {
        temperatureEnabled = false;
    }

    // Start module
    if (temperatureEnabled) {
        TemperatureStateInitialize();

        static UAVObjEvent ev;

        memset(&ev, 0, sizeof(UAVObjEvent));
        EventPeriodicCallbackCreate(&ev, onTimer, SAMPLE_PERIOD_MS / portTICK_RATE_MS);
    }

    return 0;
}

MODULE_INITCALL(TemperatureInitialize, 0);
static void onTimer(__attribute__((unused)) UAVObjEvent *ev)
{
    static TemperatureSettingsData temperatureSettings;
    static TemperatureStateData temperatureData;

    TemperatureSettingsGet(&temperatureSettings);
    TemperatureStateGet(&temperatureData);

#ifdef PIOS_INCLUDE_ADC
    // calculate the temperature (ntc)
    if (ntcTemperatureADCPin >= 0) {
        float ntc_resistance = 0;

        if (temperatureSettings.NtcVoltageDivider == TEMPERATURESETTINGS_NTCVOLTAGEDIVIDER_NTCTOGROUND) {
            ntc_resistance = temperatureSettings.NtcSerialResistor / ((temperatureSettings.NtcVoltageReference / PIOS_ADC_PinGetVolt(ntcTemperatureADCPin)) - 1);
        } else if (temperatureSettings.NtcVoltageDivider == TEMPERATURESETTINGS_NTCVOLTAGEDIVIDER_NTCTOVREF) {
            ntc_resistance = temperatureSettings.NtcSerialResistor * ((temperatureSettings.NtcVoltageReference / PIOS_ADC_PinGetVolt(ntcTemperatureADCPin)) - 1);
        }

        float steinhart = ntc_resistance / temperatureSettings.NtcNominalValue;
        steinhart  = logf(steinhart);
        steinhart /= temperatureSettings.NtcBetaCoeff;
        steinhart += 1.0f / (temperatureSettings.NtcNominalTemperature + 273.15f);
        steinhart  = 1.0f / steinhart;
        temperatureData.Temperature1 = steinhart - 273.15f;
    } else {
        temperatureData.Temperature1 = 0;
    }

    // calculate the temperature (lm35)
    if (lm35TemperatureADCPin >= 0) {
        temperatureData.Temperature2 = (PIOS_ADC_PinGetVolt(lm35TemperatureADCPin) / temperatureSettings.Lm35Sensitivity);
    } else {
        temperatureData.Temperature2 = 0;
    }
#else /* ifdef PIOS_INCLUDE_ADC */
    temperatureData.Temperature1 = 0;
    temperatureData.Temperature2 = 0;
#endif /* PIOS_INCLUDE_ADC */

    TemperatureStateSet(&temperatureData);
}

/**
 * @}
 */