AP_TempratureSensor: add support for analog sensor with polynomial

libraries/AP_TemperatureSensor/AP_TemperatureSensor.cpp

@@ -28,6 +28,7 @@
 #include "AP_TemperatureSensor_TSYS03.h"
 #include "AP_TemperatureSensor_MCP9600.h"
 #include "AP_TemperatureSensor_MAX31865.h"
+#include "AP_TemperatureSensor_Analog.h"
 
 #include <AP_Logger/AP_Logger.h>
 #include <AP_Vehicle/AP_Vehicle_Type.h>
@@ -189,6 +190,11 @@ void AP_TemperatureSensor::init()
             case AP_TemperatureSensor_Params::Type::TSYS03:
                 drivers[instance] = new AP_TemperatureSensor_TSYS03(*this, _state[instance], _params[instance]);
                 break;
+#endif
+#if AP_TEMPERATURE_SENSOR_ANALOG_ENABLED
+            case AP_TemperatureSensor_Params::Type::ANALOG:
+                drivers[instance] = new AP_TemperatureSensor_Analog(*this, _state[instance], _params[instance]);
+                break;
 #endif
             case AP_TemperatureSensor_Params::Type::NONE:
             default:

libraries/AP_TemperatureSensor/AP_TemperatureSensor.h

@@ -26,6 +26,7 @@ class AP_TemperatureSensor_TSYS01;
 class AP_TemperatureSensor_MCP9600;
 class AP_TemperatureSensor_MAX31865;
 class AP_TemperatureSensor_TSYS03;
+class AP_TemperatureSensor_Analog;
 
 class AP_TemperatureSensor
 {
@@ -34,6 +35,7 @@ class AP_TemperatureSensor
     friend class AP_TemperatureSensor_MCP9600;
     friend class AP_TemperatureSensor_MAX31865;
     friend class AP_TemperatureSensor_TSYS03;
+    friend class AP_TemperatureSensor_Analog;
 
 public:
 

libraries/AP_TemperatureSensor/AP_TemperatureSensor_Analog.cpp

@@ -0,0 +1,97 @@
+/*
+   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: -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
+

libraries/AP_TemperatureSensor/AP_TemperatureSensor_Analog.h

@@ -0,0 +1,45 @@
+/*
+   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/>.
+ */
+
+#pragma once
+
+#include "AP_TemperatureSensor_config.h"
+
+#if AP_TEMPERATURE_SENSOR_ANALOG_ENABLED
+
+#include "AP_TemperatureSensor_Backend.h"
+#include <AP_Param/AP_Param.h>
+
+class AP_TemperatureSensor_Analog : public AP_TemperatureSensor_Backend {
+public:
+    AP_TemperatureSensor_Analog(AP_TemperatureSensor &front, AP_TemperatureSensor::TemperatureSensor_State &state, AP_TemperatureSensor_Params &params);
+
+    void update(void) override;
+
+    static const struct AP_Param::GroupInfo var_info[];
+
+private:
+
+    AP_HAL::AnalogSource *_analog_source;
+
+    // Pin used to measure voltage
+    AP_Int8  _pin; 
+
+    // Polynomial coefficients to calculate temperature from voltage
+    AP_Float _a[5];
+
+};
+
+#endif // AP_TEMPERATURE_SENSOR_ANALOG_ENABLED

libraries/AP_TemperatureSensor/AP_TemperatureSensor_Params.cpp

@@ -34,7 +34,7 @@ const AP_Param::GroupInfo AP_TemperatureSensor_Params::var_info[] = {
     // @Param: TYPE
     // @DisplayName: Temperature Sensor Type
     // @Description: Enables temperature sensors
-    // @Values: 0:Disabled, 1:TSYS01, 2:MCP9600, 3:MAX31865, 4:TSYS03
+    // @Values: 0:Disabled, 1:TSYS01, 2:MCP9600, 3:MAX31865, 4:TSYS03, 5:Analog
     // @User: Standard
     // @RebootRequired: True
     AP_GROUPINFO_FLAGS("TYPE", 1, AP_TemperatureSensor_Params, type, (float)Type::NONE, AP_PARAM_FLAG_ENABLE),

libraries/AP_TemperatureSensor/AP_TemperatureSensor_Params.h

@@ -32,6 +32,7 @@ class AP_TemperatureSensor_Params {
         MCP9600                     = 2,
         MAX31865                    = 3,
         TSYS03                      = 4,
+        ANALOG                      = 5,
     };
 
     // option to map to another system component

libraries/AP_TemperatureSensor/AP_TemperatureSensor_config.h

@@ -20,6 +20,9 @@
     #define AP_TEMPERATURE_SENSOR_MAX31865_ENABLED AP_TEMPERATURE_SENSOR_ENABLED
 #endif
 
+#ifndef AP_TEMPERATURE_SENSOR_ANALOG_ENABLED
+    #define AP_TEMPERATURE_SENSOR_ANALOG_ENABLED AP_TEMPERATURE_SENSOR_ENABLED
+#endif
 
 
 // maximum number of Temperature Sensors