AP_TemperatureSensor: Add support for MCP9808 I2C temperature sensor

Tools/autotest/ardusub.py

@@ -1143,6 +1143,34 @@ def SHT3X(self):
         if m is None:
             raise NotAchievedException("Did not get good TEMP message")
 
+    def MCP9808(self):
+        '''test for the MCP9808 temperature driver'''
+
+        self.set_parameters({
+            'TEMP1_TYPE': 11,      # Replace with your MCP9808 enum
+            'TEMP1_ADDR': 0x18,   # MCP9808 default I2C address
+            'TEMP1_BUS': 0,       # Bus used by your SITL simulator
+            'TEMP_LOG': 1,
+        })
+        self.reboot_sitl()
+        self.context_push()
+        self.set_parameter('LOG_DISARMED', 1)
+        self.delay_sim_time(10, reason="temperature data to be logged")
+        self.context_pop()
+
+        dfreader = self.dfreader_for_current_onboard_log()
+
+        while True:
+            m = dfreader.recv_match(type='TEMP')
+            if m is None:
+                break
+            self.progress(m)
+            # Check for a reasonable temperature
+            if 30 < m.Temp < 90:
+                return
+
+        raise NotAchievedException("Did not get valid MCP9808 TEMP message")
+
     def MAV_mgs(self):
         '''test individual GCS backends timestamps'''
         self.reboot_sitl()
@@ -1644,6 +1672,7 @@ def tests(self):
             self.INA3221,
             self.PosHoldBounceBack,
             self.SHT3X,
+            self.MCP9808,
             self.SurfaceSensorless,
             self.GPSForYaw,
             self.WaterDepth,

Tools/scripts/build_options.py

@@ -404,6 +404,7 @@ def config_option(self):
     Feature('Sensors', 'TEMP_MLX90614', 'AP_TEMPERATURE_SENSOR_MLX90614_ENABLED', 'Enable Temp Sensor - MLX90614', 0, "TEMP"),
     Feature('Sensors', 'TEMP_SHT3X', 'AP_TEMPERATURE_SENSOR_SHT3X_ENABLED', 'Enable Temp Sensor - SHT3x', 0, "TEMP"),
     Feature('Sensors', 'TEMP_TMP119', 'AP_TEMPERATURE_SENSOR_TMP119_ENABLED', 'Enable Temp Sensor - TMP119', 0, "TEMP"),
+    Feature('Sensors', 'TEMP_MCP9808', 'AP_TEMPERATURE_SENSOR_MCP9808_ENABLED', 'Enable Temp Sensor - MCP9808', 0, "TEMP"),
 
     Feature('Sensors', 'AIRSPEED', 'AP_AIRSPEED_ENABLED', 'Enable Airspeed Sensors', 1, None),    # Default to enabled to not annoy Plane users   # NOQA: E501
     Feature('Sensors', 'BEACON', 'AP_BEACON_ENABLED', 'Enable Beacon', 0, None),

libraries/AP_TemperatureSensor/AP_TemperatureSensor.cpp

@@ -35,6 +35,7 @@
 #include "AP_TemperatureSensor_MLX90614.h"
 #include "AP_TemperatureSensor_SHT3x.h"
 #include "AP_TemperatureSensor_TMP119.h"
+#include "AP_TemperatureSensor_MCP9808.h"
 
 #include <AP_Logger/AP_Logger.h>
 #include <AP_Vehicle/AP_Vehicle_Type.h>
@@ -344,6 +345,11 @@ void AP_TemperatureSensor::init()
             case AP_TemperatureSensor_Params::Type::TMP119:
                 drivers[instance] = NEW_NOTHROW AP_TemperatureSensor_TMP119(*this, _state[instance], _params[instance]);
                 break;
+#endif
+#if AP_TEMPERATURE_SENSOR_MCP9808_ENABLED
+            case AP_TemperatureSensor_Params::Type::MCP9808:
+                drivers[instance] = NEW_NOTHROW AP_TemperatureSensor_MCP9808(*this, _state[instance], _params[instance]);
+                break;
 #endif
             case AP_TemperatureSensor_Params::Type::NONE:
             default:

libraries/AP_TemperatureSensor/AP_TemperatureSensor.h

@@ -29,6 +29,7 @@ class AP_TemperatureSensor_TSYS03;
 class AP_TemperatureSensor_Analog;
 class AP_TemperatureSensor_MLX90614;
 class AP_TemperatureSensor_TMP119;
+class AP_TemperatureSensor_MCP9808;
 
 class AP_TemperatureSensor
 {
@@ -41,6 +42,7 @@ class AP_TemperatureSensor
     friend class AP_TemperatureSensor_DroneCAN;
     friend class AP_TemperatureSensor_MLX90614;
     friend class AP_TemperatureSensor_TMP119;
+    friend class AP_TemperatureSensor_MCP9808;
 
 public:
 

libraries/AP_TemperatureSensor/AP_TemperatureSensor_MCP9808.cpp

@@ -0,0 +1,100 @@
+/*
+   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_MCP9808_ENABLED
+
+#include "AP_TemperatureSensor_MCP9808.h"
+#include <AP_HAL/AP_HAL.h>
+#include <AP_HAL/I2CDevice.h>
+#include <AP_Math/AP_Math.h>
+
+extern const AP_HAL::HAL &hal;
+
+// MCP9808 register addresses
+#define MCP9808_REG_AMBIENT_TEMP    0x05    // ambient temperature register
+#define MCP9808_REG_RESOLUTION      0x08    // resolution register
+// Resolution register - 0.25°C resolution (65ms conversion time)
+#define MCP9808_RESOLUTION_VALUE    0x01
+
+void AP_TemperatureSensor_MCP9808::init()
+{
+    _params.bus_address.set_default(AP_TEMPERATURE_SENSOR_MCP9808_DEFAULT_I2C_ADDR);
+    _dev = hal.i2c_mgr->get_device_ptr( _params.bus, _params.bus_address);
+    if (_dev == nullptr) {
+        return;
+    }
+    WITH_SEMAPHORE(_dev->get_semaphore());
+    // Increase retries during startup
+    _dev->set_retries(10);
+    // Configure sensor resolution
+    if (!write_register8(MCP9808_REG_RESOLUTION, MCP9808_RESOLUTION_VALUE)) {
+        return;
+    }
+    // Reduce retries during normal operation
+    _dev->set_retries(3);
+    // Poll temperature at 10Hz (100ms)
+    _dev->register_periodic_callback(100 * AP_USEC_PER_MSEC, FUNCTOR_BIND_MEMBER(&AP_TemperatureSensor_MCP9808::_timer, void));
+}
+
+void AP_TemperatureSensor_MCP9808::_timer(void)
+{
+    uint16_t raw;
+    if (!read_registers(MCP9808_REG_AMBIENT_TEMP, raw)) {
+        return;
+    }
+    // MCP9808 temperature register format:
+    // bit15     : Alert flag
+    // bit14-13  : Temperature alert status
+    // bit12     : Sign bit
+    // bit11-0   : Temperature data
+    //
+    // Temperature register LSB is always 0.0625°C
+    int16_t temp_raw = raw & 0x1FFF;
+    // Sign extend negative temperature values
+    if (temp_raw & 0x1000) {
+        temp_raw |= 0xE000;
+    }
+    float temp = temp_raw * 0.0625f;
+    set_temperature(temp);
+}
+
+bool AP_TemperatureSensor_MCP9808::read_registers(uint8_t reg, uint16_t &value) const
+{
+    uint8_t val[2];
+    if (!_dev->transfer(&reg, 1, val, sizeof(val))) {
+        return false;
+    }
+    // MCP9808 registers are 16-bit big endian
+    value = UINT16_VALUE(val[0], val[1]);
+    return true;
+}
+
+bool AP_TemperatureSensor_MCP9808::write_register8(uint8_t reg, uint8_t value) const
+{
+    // Registers are 8-bit big endian
+    uint8_t buf[2] = {reg, value};
+    return _dev->transfer(buf, sizeof(buf), nullptr, 0);
+}
+
+bool AP_TemperatureSensor_MCP9808::write_register(uint8_t reg, uint16_t value) const
+{
+    // Registers are 16-bit big endian
+    uint8_t buf[3] {reg, uint8_t(value >> 8), uint8_t(value & 0xFF)};
+    return _dev->transfer(buf, sizeof(buf), nullptr, 0);
+}
+
+#endif // AP_TEMPERATURE_SENSOR_MCP9808_ENABLED

libraries/AP_TemperatureSensor/AP_TemperatureSensor_MCP9808.h

@@ -0,0 +1,55 @@
+/*
+   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/>.
+ */
+
+/*
+ * I2C driver for Microchip MCP9808 high-accuracy digital temperature sensor.
+ *
+ * The MCP9808 is a digital temperature sensor with 0.0625°C resolution.
+ * It communicates over I2C and provides a 16-bit ambient temperature register.
+ */
+
+#pragma once
+#include "AP_TemperatureSensor_Backend.h"
+
+#if AP_TEMPERATURE_SENSOR_MCP9808_ENABLED
+
+#ifndef AP_TEMPERATURE_SENSOR_MCP9808_DEFAULT_I2C_ADDR
+#define AP_TEMPERATURE_SENSOR_MCP9808_DEFAULT_I2C_ADDR 0x18
+#endif
+
+
+class AP_TemperatureSensor_MCP9808 : public AP_TemperatureSensor_Backend {
+    using AP_TemperatureSensor_Backend::AP_TemperatureSensor_Backend;
+public:
+
+    __INITFUNC__ void init(void) override;
+
+    void update() override {};
+
+private:
+    // update the temperature, called at 20Hz
+    void _timer(void);
+
+    // read a 16-bit big-endian register
+    bool read_registers(uint8_t reg, uint16_t &value) const;
+
+    // write a 16-bit big-endian register
+    bool write_register(uint8_t reg, uint16_t value) const;
+
+    // write a 8-bit big-endian register
+    bool write_register8(uint8_t reg, uint8_t value) const;
+};
+
+#endif // AP_TEMPERATURE_SENSOR_MCP9808_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 2 or 4 wire, 4:TSYS03, 5:Analog, 6:DroneCAN, 7:MLX90614, 8:SHT3x, 9:MAX31865 3 wire, 10:TMP119
+    // @Values: 0:Disabled, 1:TSYS01, 2:MCP9600, 3:MAX31865 2 or 4 wire, 4:TSYS03, 5:Analog, 6:DroneCAN, 7:MLX90614, 8:SHT3x, 9:MAX31865 3 wire, 10:TMP119 ,11:MCP9808
     // @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

@@ -38,6 +38,7 @@ class AP_TemperatureSensor_Params {
         SHT3x                       = 8,
         MAX31865_3_wire             = 9,
         TMP119                      = 10,
+        MCP9808                     = 11,
     };
 
     // option to map to another system component

libraries/AP_TemperatureSensor/AP_TemperatureSensor_config.h

@@ -47,6 +47,11 @@
 #define AP_TEMPERATURE_SENSOR_TMP119_ENABLED AP_TEMPERATURE_SENSOR_BACKEND_DEFAULT_ENABLED
 #endif  // AP_TEMPERATURE_SENSOR_TMP119_ENABLED
 
+
+#ifndef AP_TEMPERATURE_SENSOR_MCP9808_ENABLED
+#define AP_TEMPERATURE_SENSOR_MCP9808_ENABLED AP_TEMPERATURE_SENSOR_BACKEND_DEFAULT_ENABLED
+#endif   // AP_TEMPERATURE_SENSOR_MCP9808_ENABLED
+
 // maximum number of Temperature Sensors
 #ifndef AP_TEMPERATURE_SENSOR_MAX_INSTANCES
 #define AP_TEMPERATURE_SENSOR_MAX_INSTANCES             3

libraries/SITL/SIM_I2C.cpp

@@ -45,6 +45,7 @@
 #include "SIM_Temperature_SHT3x.h"
 #include "SIM_Temperature_TSYS01.h"
 #include "SIM_Temperature_TSYS03.h"
+#include "SIM_Temperature_MCP9808.h"
 #include "SIM_TeraRangerI2C.h"
 #include "SIM_TFS20L.h"
 #include "SIM_ToshibaLED.h"
@@ -98,6 +99,9 @@ static TSYS03 tsys03;
 #if AP_SIM_TEMPERATURE_MCP9600_ENABLED
 static MCP9600 mcp9600;
 #endif
+#if AP_SIM_TEMPERATURE_MCP9808_ENABLED
+static MCP9808 mcp9808;
+#endif
 #if AP_SIM_ICM40609_ENABLED
 static ICM40609 icm40609;
 #endif
@@ -162,6 +166,9 @@ struct i2c_device_at_address {
 #if AP_SIM_TEMPERATURE_MCP9600_ENABLED
     { 0, 0x60, mcp9600 }, // 0x60 is low address
 #endif
+#if AP_SIM_TEMPERATURE_MCP9808_ENABLED
+    { 0, 0x18, mcp9808 }, // MCP9808 default address
+#endif
 #if AP_SIM_MAXSONAR_I2C_XL_ENABLED
     { 0, 0x71, maxsonari2cxl_2 }, // RNGFNDx_TYPE = 2, RNGFNDx_ADDR = 113
 #endif

libraries/SITL/SIM_Temperature_MCP9808.cpp

@@ -0,0 +1,84 @@
+/*
+ * SITL simulation for MCP9808 temperature sensor
+ */
+
+#include "SIM_config.h"
+
+#if AP_SIM_TEMPERATURE_MCP9808_ENABLED
+
+#include "SIM_Temperature_MCP9808.h"
+#include <AP_HAL/AP_HAL.h>
+#include <AP_Math/AP_Math.h>
+using namespace SITL;
+
+void MCP9808::init()
+{
+    set_debug(true);
+    // Configuration register
+    add_register("CONFIG", MCP9808DevReg::CONFIG, 2, I2CRegisters::RegMode::RDWR);
+    set_register(MCP9808DevReg::CONFIG, uint16_t(htobe16(0x0000)));
+    // Ambient temperature register
+    add_register("AMBIENT_TEMP", MCP9808DevReg::AMBIENT_TEMP, 2, I2CRegisters::RegMode::RDONLY);
+    // Resolution register
+    add_register("RESOLUTION", MCP9808DevReg::RESOLUTION, 1, I2CRegisters::RegMode::RDWR);
+    // Default power-up resolution
+    // 0x03 = 0.0625°C, 250 ms
+    set_register(MCP9808DevReg::RESOLUTION, uint8_t(0x03));
+}
+
+void MCP9808::update(const Aircraft &aircraft)
+{
+    const uint32_t now_ms = AP_HAL::millis();
+    // Read current resolution selected by ArduPilot
+    uint8_t resolution;
+    get_reg_value(MCP9808DevReg::RESOLUTION, resolution);
+
+    uint32_t conversion_time_ms = 250;
+
+    switch (resolution)
+    {
+    case 0x00:
+        conversion_time_ms = 30;
+        break;
+
+    case 0x01:
+        conversion_time_ms = 65;
+        break;
+
+    case 0x02:
+        conversion_time_ms = 130;
+        break;
+
+    case 0x03:
+    default:
+        conversion_time_ms = 250;
+        break;
+    }
+
+    if ((now_ms - last_temperature_update_ms) < conversion_time_ms) {
+        return;
+    }
+
+    last_temperature_update_ms = now_ms;
+
+    const float period_s = 10.0f;  // One complete cycle every 10 sec
+    const float phase = (2.0f * M_PI * (now_ms * 0.001f)) / period_s;
+    const float temperature = 60.0f + 35.0f * sinf(phase);
+
+    // MCP9808 resolution = 0.0625°C
+    int16_t raw_temperature = int16_t(temperature / 0.0625f);
+    uint16_t value = uint16_t(raw_temperature & 0x0FFF);
+
+    if (temperature < 0) {
+        value |= (1 << 12);
+    }
+    set_register(
+        MCP9808DevReg::AMBIENT_TEMP, uint16_t(htobe16(value)));
+}
+
+int MCP9808::rdwr(I2C::i2c_rdwr_ioctl_data *&data)
+{
+    return I2CRegisters_ConfigurableLength::rdwr(data);
+}
+
+#endif // AP_SIM_TEMPERATURE_MCP9808_ENABLED