Simon Cooksey
Pinned to some recent date
Diff: features/FEATURE_BLE/ble/services/HealthThermometerService.h
- Revision:
- 0:fb7af294d5d9
diff -r 000000000000 -r fb7af294d5d9 features/FEATURE_BLE/ble/services/HealthThermometerService.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/features/FEATURE_BLE/ble/services/HealthThermometerService.h Thu Nov 17 16:43:53 2016 +0000
@@ -0,0 +1,150 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __BLE_HEALTH_THERMOMETER_SERVICE_H__
+#define __BLE_HEALTH_THERMOMETER_SERVICE_H__
+
+#include "ble/BLE.h"
+
+/**
+* @class HealthThermometerService
+* @brief BLE Health Thermometer Service. This service provides the location of the thermometer and the temperature.
+* Service: https://developer.bluetooth.org/gatt/profiles/Pages/ProfileViewer.aspx?u=org.bluetooth.profile.health_thermometer.xml
+* Temperature Measurement: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.temperature_measurement.xml
+* Temperature Type: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.temperature_type.xml
+*/
+class HealthThermometerService {
+public:
+ /**
+ * @enum Sensor Location.
+ * @brief Location of sensor on the body.
+ */
+ enum SensorLocation_t {
+ LOCATION_ARMPIT = 1, /*!< Armpit. */
+ LOCATION_BODY, /*!< Body. */
+ LOCATION_EAR, /*!< Ear. */
+ LOCATION_FINGER, /*!< Finger. */
+ LOCATION_GI_TRACT, /*!< GI tract */
+ LOCATION_MOUTH, /*!< Mouth. */
+ LOCATION_RECTUM, /*!< Rectum. */
+ LOCATION_TOE, /*!< Toe. */
+ LOCATION_EAR_DRUM, /*!< Eardrum. */
+ };
+
+public:
+ /**
+ * @brief Add the Health Thermometer Service to an existing BLE object, initialize with temperature and location.
+ * @param[ref] _ble Reference to the BLE device.
+ * @param[in] initialTemp Initial value in celsius.
+ * @param[in] _location
+ */
+ HealthThermometerService(BLE &_ble, float initialTemp, uint8_t _location) :
+ ble(_ble),
+ valueBytes(initialTemp),
+ tempMeasurement(GattCharacteristic::UUID_TEMPERATURE_MEASUREMENT_CHAR, (TemperatureValueBytes *)valueBytes.getPointer(), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),
+ tempLocation(GattCharacteristic::UUID_TEMPERATURE_TYPE_CHAR, &_location) {
+
+ GattCharacteristic *hrmChars[] = {&tempMeasurement, &tempLocation, };
+ GattService hrmService(GattService::UUID_HEALTH_THERMOMETER_SERVICE, hrmChars, sizeof(hrmChars) / sizeof(GattCharacteristic *));
+
+ ble.addService(hrmService);
+ }
+
+ /**
+ * @brief Update the temperature being broadcast.
+ *
+ * @param[in] temperature
+ * Floating point value of the temperature.
+ *
+ */
+ void updateTemperature(float temperature) {
+ if (ble.getGapState().connected) {
+ valueBytes.updateTemperature(temperature);
+ ble.gattServer().write(tempMeasurement.getValueHandle(), valueBytes.getPointer(), sizeof(TemperatureValueBytes));
+ }
+ }
+
+ /**
+ * @brief Update the location.
+ * @param loc
+ * New location value.
+ */
+ void updateLocation(SensorLocation_t loc) {
+ ble.gattServer().write(tempLocation.getValueHandle(), reinterpret_cast<uint8_t *>(&loc), sizeof(uint8_t));
+ }
+
+private:
+ /* Private internal representation for the bytes used to work with the vaulue of the temperature characteristic. */
+ struct TemperatureValueBytes {
+ static const unsigned OFFSET_OF_FLAGS = 0;
+ static const unsigned OFFSET_OF_VALUE = OFFSET_OF_FLAGS + sizeof(uint8_t);
+ static const unsigned SIZEOF_VALUE_BYTES = sizeof(uint8_t) + sizeof(float);
+
+ static const unsigned TEMPERATURE_UNITS_FLAG_POS = 0;
+ static const unsigned TIMESTAMP_FLAG_POS = 1;
+ static const unsigned TEMPERATURE_TYPE_FLAG_POS = 2;
+
+ static const uint8_t TEMPERATURE_UNITS_CELSIUS = 0;
+ static const uint8_t TEMPERATURE_UNITS_FAHRENHEIT = 1;
+
+ TemperatureValueBytes(float initialTemperature) : bytes() {
+ /* Assumption: temperature values are expressed in celsius */
+ bytes[OFFSET_OF_FLAGS] = (TEMPERATURE_UNITS_CELSIUS << TEMPERATURE_UNITS_FLAG_POS) |
+ (false << TIMESTAMP_FLAG_POS) |
+ (false << TEMPERATURE_TYPE_FLAG_POS);
+ updateTemperature(initialTemperature);
+ }
+
+ void updateTemperature(float temp) {
+ uint32_t temp_ieee11073 = quick_ieee11073_from_float(temp);
+ memcpy(&bytes[OFFSET_OF_VALUE], &temp_ieee11073, sizeof(float));
+ }
+
+ uint8_t *getPointer(void) {
+ return bytes;
+ }
+
+ const uint8_t *getPointer(void) const {
+ return bytes;
+ }
+
+private:
+ /**
+ * @brief A very quick conversion between a float temperature and 11073-20601 FLOAT-Type.
+ * @param temperature The temperature as a float.
+ * @return The temperature in 11073-20601 FLOAT-Type format.
+ */
+ uint32_t quick_ieee11073_from_float(float temperature) {
+ uint8_t exponent = 0xFE; //Exponent is -2
+ uint32_t mantissa = (uint32_t)(temperature * 100);
+
+ return (((uint32_t)exponent) << 24) | mantissa;
+ }
+
+private:
+ /* First byte: 8-bit flags. Second field is a float holding the temperature value. */
+ /* See https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.temperature_measurement.xml */
+ uint8_t bytes[SIZEOF_VALUE_BYTES];
+ };
+
+protected:
+ BLE &ble;
+ TemperatureValueBytes valueBytes;
+ ReadOnlyGattCharacteristic<TemperatureValueBytes> tempMeasurement;
+ ReadOnlyGattCharacteristic<uint8_t> tempLocation;
+};
+
+#endif /* #ifndef __BLE_HEALTH_THERMOMETER_SERVICE_H__*/