George Roussos / BLE_Temperature

BLE temperature profile using digital DS1820 or analog LM35 sensors

Dependencies:   DS1820

main.cpp@0:637031152314, 2015-03-07 (annotated)

Committer:
gkroussos
Date:
Sat Mar 07 16:23:41 2015 +0000
Revision:
0:637031152314
Working version 1.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gkroussos 0:637031152314 1 /*----------------------------------------------------------------------------
gkroussos 0:637031152314 2 LAB EXERCISE - BLE Thermometer
gkroussos 0:637031152314 3 ----------------------------------------
gkroussos 0:637031152314 4 In this exercise you will write a program which will turn your board into
gkroussos 0:637031152314 5 a BLE thermometer. You will be able to check the temperature with any device
gkroussos 0:637031152314 6 that can read BLE temperature readings.
gkroussos 0:637031152314 7
gkroussos 0:637031152314 8 GOOD LUCK!
gkroussos 0:637031152314 9 *----------------------------------------------------------------------------*/
gkroussos 0:637031152314 10
gkroussos 0:637031152314 11 #include "mbed.h"
gkroussos 0:637031152314 12 #include "DS1820.h"
gkroussos 0:637031152314 13 #include "nRF51822n.h"
gkroussos 0:637031152314 14
gkroussos 0:637031152314 15 nRF51822n nrf;
gkroussos 0:637031152314 16 DS1820 probe(P0_20);
gkroussos 0:637031152314 17 //AnalogIn LM35(P0_2); // Uncomment for analog LM35 sensor from Maplin
gkroussos 0:637031152314 18 Ticker oneSec;
gkroussos 0:637031152314 19
gkroussos 0:637031152314 20 // LEDs for indication
gkroussos 0:637031152314 21 DigitalOut oneSecLed(LED1);
gkroussos 0:637031152314 22 DigitalOut adStateLed(LED2);
gkroussos 0:637031152314 23
gkroussos 0:637031152314 24 const static char deviceName[] = "** Temperature Sensor **";
gkroussos 0:637031152314 25
gkroussos 0:637031152314 26 // Health Thermometer Service
gkroussos 0:637031152314 27 uint8_t tempSensorPayload[5] = { 0, 0, 0, 0, 0 };
gkroussos 0:637031152314 28 GattService tempSensorService (GattService::UUID_HEALTH_THERMOMETER_SERVICE);
gkroussos 0:637031152314 29 GattCharacteristic tempSensorChar (GattCharacteristic::UUID_TEMPERATURE_MEASUREMENT_CHAR, 5, 5, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_INDICATE);
gkroussos 0:637031152314 30
gkroussos 0:637031152314 31 // Advertising data and parameters
gkroussos 0:637031152314 32 GapAdvertisingData advData;
gkroussos 0:637031152314 33 GapAdvertisingData scanResponse;
gkroussos 0:637031152314 34 GapAdvertisingParams advParams ( GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED );
gkroussos 0:637031152314 35
gkroussos 0:637031152314 36 // Function constructors
gkroussos 0:637031152314 37 uint32_t quick_ieee11073_from_float(float temperature);
gkroussos 0:637031152314 38 void updateTemp(void);
gkroussos 0:637031152314 39
gkroussos 0:637031152314 40 class GapEventHandler : public GapEvents {
gkroussos 0:637031152314 41 // When a client device connects we need to turn off the advertising LED
gkroussos 0:637031152314 42 virtual void onConnected(void){
gkroussos 0:637031152314 43 adStateLed = 0;
gkroussos 0:637031152314 44 }
gkroussos 0:637031152314 45
gkroussos 0:637031152314 46 // When a client device disconnects we need to start advertising again
gkroussos 0:637031152314 47 virtual void onDisconnected(void) {
gkroussos 0:637031152314 48 nrf.getGap().startAdvertising(advParams);
gkroussos 0:637031152314 49 adStateLed = 1;
gkroussos 0:637031152314 50 }
gkroussos 0:637031152314 51 };
gkroussos 0:637031152314 52
gkroussos 0:637031152314 53
gkroussos 0:637031152314 54 int main(void){
gkroussos 0:637031152314 55
gkroussos 0:637031152314 56 // Start the one second ticker
gkroussos 0:637031152314 57 oneSec.attach(updateTemp, 1);
gkroussos 0:637031152314 58
gkroussos 0:637031152314 59 nrf.getGap().setEventHandler(new GapEventHandler());
gkroussos 0:637031152314 60
gkroussos 0:637031152314 61 // Start the BLE radio
gkroussos 0:637031152314 62 nrf.init();
gkroussos 0:637031152314 63 nrf.reset();
gkroussos 0:637031152314 64
gkroussos 0:637031152314 65 // Add GAP data, but don't start advertising
gkroussos 0:637031152314 66 advData.addFlags((GapAdvertisingData::Flags)(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE));
gkroussos 0:637031152314 67 advData.addData(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t*)deviceName, sizeof(deviceName));
gkroussos 0:637031152314 68 advData.addAppearance(GapAdvertisingData::GENERIC_THERMOMETER);
gkroussos 0:637031152314 69 nrf.getGap().setAdvertisingData(advData, scanResponse);
gkroussos 0:637031152314 70
gkroussos 0:637031152314 71 // Temperature Sensor Service
gkroussos 0:637031152314 72 tempSensorService.addCharacteristic(tempSensorChar);
gkroussos 0:637031152314 73 nrf.getGattServer().addService(tempSensorService);
gkroussos 0:637031152314 74
gkroussos 0:637031152314 75 // Finally start advertising (can't start advertising before all services are added)
gkroussos 0:637031152314 76 nrf.getGap().startAdvertising(advParams);
gkroussos 0:637031152314 77 adStateLed = 1;
gkroussos 0:637031152314 78
gkroussos 0:637031152314 79 while(1){
gkroussos 0:637031152314 80 }
gkroussos 0:637031152314 81 }
gkroussos 0:637031152314 82
gkroussos 0:637031152314 83 // Update temperature
gkroussos 0:637031152314 84 void updateTemp(void){
gkroussos 0:637031152314 85 oneSecLed = !oneSecLed;
gkroussos 0:637031152314 86
gkroussos 0:637031152314 87 probe.convertTemperature(true, DS1820::all_devices); // initialise DS1820 digital temperature sensor
gkroussos 0:637031152314 88 float temperature = probe.temperature(); // obtain reading
gkroussos 0:637031152314 89 //float temperature = ((LM35*3.3)-0.600)*100.0; // for use with analog LM35 sensor from Maplin
gkroussos 0:637031152314 90 uint32_t temp_ieee11073 = quick_ieee11073_from_float(temperature);
gkroussos 0:637031152314 91 memcpy(tempSensorPayload+1, &temp_ieee11073, 4);
gkroussos 0:637031152314 92 nrf.getGattServer().updateValue(tempSensorChar.handle, tempSensorPayload, sizeof(tempSensorPayload));
gkroussos 0:637031152314 93 }
gkroussos 0:637031152314 94
gkroussos 0:637031152314 95 // Quick conversion to an IEEE11073 format
gkroussos 0:637031152314 96 uint32_t quick_ieee11073_from_float(float temperature){
gkroussos 0:637031152314 97 uint8_t exponent = 0xFF;
gkroussos 0:637031152314 98 uint32_t mantissa = (uint32_t)(temperature*10);
gkroussos 0:637031152314 99 return ( ((uint32_t)exponent) << 24) | mantissa;
gkroussos 0:637031152314 100 }
gkroussos 0:637031152314 101