microbit: First implementation of Temperature Service

inc/MicroBit.h

@@ -40,6 +40,7 @@
 #include "MicroBitMagnetometerService.h"
 #include "MicroBitButtonService.h"
 #include "MicroBitIOPinService.h"
+#include "MicroBitTemperatureService.h"
 #include "ExternalEvents.h"
 
 // MicroBit::flags values
@@ -117,6 +118,7 @@ class MicroBit
     MicroBitMagnetometerService     *ble_magnetometer_service;
     MicroBitButtonService           *ble_button_service;
     MicroBitIOPinService            *ble_io_pin_service;
+    MicroBitTemperatureService      *ble_temperature_service;
     
     /**
       * Constructor. 

inc/MicroBitCompass.h

@@ -36,6 +36,8 @@
 #define MAG_CTRL_REG1 0x10
 #define MAG_CTRL_REG2 0x11
 
+#define MICROBIT_COMPASS_TEMPERATURE_SENSE_PERIOD 1000
+
 /**
   * Configuration options
   */
@@ -56,6 +58,7 @@ extern const MAG3110SampleRateConfig MAG3110SampleRate[];
 #define MICROBIT_COMPASS_EVT_CAL_START          2
 #define MICROBIT_COMPASS_EVT_CAL_END            3
 #define MICROBIT_COMPASS_EVT_DATA_UPDATE        4
+#define MICROBIT_COMPASS_EVT_TEMPERATURE_UPDATE 5
 
 /*
  * Status Bits
@@ -77,6 +80,7 @@ struct CompassSample
     int16_t         x;
     int16_t         y;
     int16_t         z;
+    int16_t         temperature;
     
     CompassSample()
     {
@@ -102,6 +106,8 @@ class MicroBitCompass : public MicroBitComponent
     uint16_t            address;                  // I2C address of the magnetmometer.  
     uint16_t            samplePeriod;             // The time between samples, in millseconds.
     unsigned long       eventStartTime;           // used to store the current system clock when async calibration has started
+    unsigned long       temperatureSampleTime;    // used to store the current system clock when async calibration has started
+    uint8_t             temperature;              // the current die temperture of the compass chip.
 
     public:
     
@@ -208,6 +214,12 @@ class MicroBitCompass : public MicroBitComponent
       */    
     int getZ();    
 
+    /**
+      * Reads the currently die temperature of the compass. 
+      * @return The temperature, in degrees celsius.
+      */
+    int getTemperature();
+
     /**
       * Perform the asynchronous calibration of the compass.
       * This will fire MICROBIT_COMPASS_EVT_CAL_START and MICROBIT_COMPASS_EVT_CAL_END when finished.

inc/MicroBitConfig.h

@@ -187,6 +187,12 @@
 #define MICROBIT_BLE_IO_PIN_SERVICE             1
 #endif
 
+// This enables live access to the die temperature sensors on the micro:bit.
+// Set '1' to enable. 
+#ifndef MICROBIT_BLE_TEMPERATURE_SERVICE
+#define MICROBIT_BLE_TEMPERATURE_SERVICE        1
+#endif
+
 // Defines the maximum length strong that can be written to the
 // display over BLE.
 #ifndef MICROBIT_BLE_MAXIMUM_SCROLLTEXT

inc/MicroBitTemperatureService.h

@@ -0,0 +1,45 @@
+#ifndef MICROBIT_TEMPERATURE_SERVICE_H
+#define MICROBIT_TEMPERATURE_SERVICE_H
+
+#include "MicroBit.h"
+
+// UUIDs for our service and characteristics
+extern const uint8_t  MicroBitTemperatureServiceUUID[];
+extern const uint8_t  MicroBitTemperatureServiceDataUUID[];
+
+
+/**
+  * Class definition for a MicroBit BLE Temperture Service.
+  * Provides access to live temperature data via BLE.
+  */
+class MicroBitTemperatureService
+{                                    
+    public:
+    
+    /**
+      * Constructor. 
+      * Create a representation of the TempertureService
+      * @param _ble The instance of a BLE device that we're running on.
+      */
+    MicroBitTemperatureService(BLEDevice &_ble);  
+    
+    /**
+     * Temperature update callback
+     */
+    void temperatureUpdate(MicroBitEvent e);
+
+    private:
+
+    // Bluetooth stack we're running on.
+    BLEDevice           &ble;
+
+    // memory for our 8 bit temperature characteristic.
+    int8_t             temperatureDataCharacteristicBuffer;
+
+    // Handles to access each characteristic when they are held by Soft Device.
+    GattAttribute::Handle_t temperatureDataCharacteristicHandle;
+};
+
+
+#endif
+

source/CMakeLists.txt

@@ -35,6 +35,7 @@ set(YOTTA_AUTO_MICROBIT-DAL_CPP_FILES
     "ble-services/MicroBitMagnetometerService.cpp"
     "ble-services/MicroBitButtonService.cpp"
     "ble-services/MicroBitIOPinService.cpp"
+    "ble-services/MicroBitTemperatureService.cpp"
 )
 
 if (YOTTA_CFG_MICROBIT_CONFIGFILE)

source/MicroBit.cpp

@@ -137,6 +137,10 @@ void MicroBit::init()
     ble_io_pin_service = new MicroBitIOPinService(*ble);
 #endif
 
+#if CONFIG_ENABLED(MICROBIT_BLE_TEMPERATURE_SERVICE) 
+    ble_temperature_service = new MicroBitTemperatureService(*ble);
+#endif
+
     // Setup advertising.
     ble->accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
     ble->accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)MICROBIT_BLE_DEVICE_NAME, sizeof(MICROBIT_BLE_DEVICE_NAME));

source/MicroBitCompass.cpp

@@ -28,6 +28,8 @@ MicroBitCompass::MicroBitCompass(uint16_t id, uint16_t address) : average(), sam
     
     //initialise eventStartTime to 0
     this->eventStartTime = 0;
+    this->temperatureSampleTime = 0;
+    this->temperature = 0;
     
     // Enable automatic reset after each sample;
     writeCommand(MAG_CTRL_REG2, 0xA0);
@@ -183,6 +185,20 @@ void MicroBitCompass::idleTick()
             MicroBitEvent e(id, MICROBIT_COMPASS_EVT_DATA_UPDATE);
         }
     }
+
+    // Update the temperature value if needed
+    if (temperatureSampleTime == 0 || temperatureSampleTime > ticks)
+    {
+        uint8_t data;
+
+        readCommand(MAG_DIE_TEMP, &data, 1);    
+        temperature = data;
+
+        temperatureSampleTime = ticks + MICROBIT_COMPASS_TEMPERATURE_SENSE_PERIOD;
+
+        // Indicate that a new sample is available
+        MicroBitEvent e(id, MICROBIT_COMPASS_EVT_TEMPERATURE_UPDATE);
+    }
 }
 
 /**
@@ -294,6 +310,15 @@ int MicroBitCompass::whoAmI()
     return (int)data;
 }
 
+/**
+ * Reads the currently die temperature of the compass. 
+ * @return The temperature, in degrees celsius.
+ */
+int MicroBitCompass::getTemperature()
+{
+    return temperature;
+}
+
 /**
   * Perform a calibration of the compass.
   * This will fire MICROBIT_COMPASS_EVT_CAL_START.

source/ble-services/MicroBitIOPinService.cpp

@@ -248,15 +248,15 @@ const uint8_t  MicroBitIOPinServiceUUID[] = {
 };
 
 const uint8_t  MicroBitIOPinServiceIOConfigurationUUID[] = {
-    0xe9,0x5d,0x58,0x99,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+    0xe9,0x5d,0xb9,0xfe,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
 };
 
 const uint8_t  MicroBitIOPinServiceADConfigurationUUID[] = {
-    0xe9,0x5d,0x8d,0x00,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+    0xe9,0x5d,0x58,0x99,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
 };
 
 const uint8_t MicroBitIOPinServiceDataUUID[] = {
-    0xe9,0x5d,0xc5,0x8c,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+    0xe9,0x5d,0x8d,0x00,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
 };
 
 MicroBitPin * const MicroBitIOPins[] = { 

source/ble-services/MicroBitTemperatureService.cpp

@@ -0,0 +1,54 @@
+/**
+  * Class definition for the custom MicroBit Temperature Service.
+  * Provides a BLE service to remotely read the state of the temperature, and configure its behaviour.
+  */
+  
+#include "MicroBit.h"
+#include "ble/UUID.h"
+
+#include "MicroBitTemperatureService.h"
+
+/**
+  * Constructor. 
+  * Create a representation of the TemperatureService
+  * @param _ble The instance of a BLE device that we're running on.
+  */
+MicroBitTemperatureService::MicroBitTemperatureService(BLEDevice &_ble) : 
+        ble(_ble) 
+{
+    // Create the data structures that represent each of our characteristics in Soft Device.
+    GattCharacteristic  temperatureDataCharacteristic(MicroBitTemperatureServiceDataUUID, (uint8_t *)temperatureDataCharacteristicBuffer, 0, 
+    sizeof(temperatureDataCharacteristicBuffer), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
+
+    // Initialise our characteristic values.
+    temperatureDataCharacteristicBuffer = 0;
+    
+    GattCharacteristic *characteristics[] = {&temperatureDataCharacteristic};
+    GattService         service(MicroBitTemperatureServiceUUID, characteristics, sizeof(characteristics) / sizeof(GattCharacteristic *));
+
+    ble.addService(service);
+
+    temperatureDataCharacteristicHandle = temperatureDataCharacteristic.getValueHandle();
+    ble.updateCharacteristicValue(temperatureDataCharacteristicHandle, (const uint8_t *)&temperatureDataCharacteristicBuffer, sizeof(temperatureDataCharacteristicBuffer));
+
+    uBit.MessageBus.listen(MICROBIT_ID_COMPASS, MICROBIT_COMPASS_EVT_TEMPERATURE_UPDATE, this, &MicroBitTemperatureService::temperatureUpdate, MESSAGE_BUS_LISTENER_NONBLOCKING | MESSAGE_BUS_LISTENER_URGENT);
+}
+
+/**
+  * Temperature update callback
+  */
+void MicroBitTemperatureService::temperatureUpdate(MicroBitEvent e)
+{
+    temperatureDataCharacteristicBuffer = uBit.compass.getTemperature();
+    ble.gattServer().notify(temperatureDataCharacteristicHandle,(uint8_t *)temperatureDataCharacteristicBuffer, sizeof(temperatureDataCharacteristicBuffer));
+}
+
+const uint8_t  MicroBitTemperatureServiceUUID[] = {
+    0xe9,0x5d,0x61,0x00,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+const uint8_t  MicroBitTemperatureServiceDataUUID[] = {
+    0xe9,0x5d,0x8a,0x38,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+