George Roussos / BLE_Temperature_Exercise

BLE Temperature Service Mobile and Ubiquitous Computing Module Birkbeck College

Dependencies:   DS1820

main.cpp@0:dd0fea342ad2, 2015-03-08 (annotated)

Committer:
gkroussos
Date:
Sun Mar 08 19:42:20 2015 +0000
Revision:
0:dd0fea342ad2
BLE Temperature Service ; Mobile and Ubiquitous Computing Module; Birkbeck College

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gkroussos 0:dd0fea342ad2 1 /*----------------------------------------------------------------------------
gkroussos 0:dd0fea342ad2 2 LAB EXERCISE - BLE Thermometer
gkroussos 0:dd0fea342ad2 3 ----------------------------------------
gkroussos 0:dd0fea342ad2 4 In this exercise you will write a program which will turn your board into
gkroussos 0:dd0fea342ad2 5 a BLE thermometer. You will be able to check the temperature with any device
gkroussos 0:dd0fea342ad2 6 that can read BLE temperature readings.
gkroussos 0:dd0fea342ad2 7
gkroussos 0:dd0fea342ad2 8 GOOD LUCK!
gkroussos 0:dd0fea342ad2 9 *----------------------------------------------------------------------------*/
gkroussos 0:dd0fea342ad2 10
gkroussos 0:dd0fea342ad2 11 #include "mbed.h"
gkroussos 0:dd0fea342ad2 12 #include "DS1820.h"
gkroussos 0:dd0fea342ad2 13 #include "nRF51822n.h"
gkroussos 0:dd0fea342ad2 14
gkroussos 0:dd0fea342ad2 15 nRF51822n nrf;
gkroussos 0:dd0fea342ad2 16 DS1820 probe(P0_20);
gkroussos 0:dd0fea342ad2 17 //AnalogIn LM35(P0_2); // Uncomment for analog LM35 sensor from Maplin
gkroussos 0:dd0fea342ad2 18 Ticker oneSec;
gkroussos 0:dd0fea342ad2 19
gkroussos 0:dd0fea342ad2 20 // LEDs for indication
gkroussos 0:dd0fea342ad2 21 DigitalOut oneSecLed(LED1);
gkroussos 0:dd0fea342ad2 22 DigitalOut adStateLed(LED2);
gkroussos 0:dd0fea342ad2 23
gkroussos 0:dd0fea342ad2 24 const static char deviceName[] = "** Temperature Sensor **";
gkroussos 0:dd0fea342ad2 25
gkroussos 0:dd0fea342ad2 26 // Health Thermometer Service
gkroussos 0:dd0fea342ad2 27 uint8_t tempSensorPayload[5] = { 0, 0, 0, 0, 0 };
gkroussos 0:dd0fea342ad2 28 // Add the temperature sensor service and characteristics
gkroussos 0:dd0fea342ad2 29 // <Write your code here>
gkroussos 0:dd0fea342ad2 30
gkroussos 0:dd0fea342ad2 31
gkroussos 0:dd0fea342ad2 32 // Function constructors
gkroussos 0:dd0fea342ad2 33 uint32_t quick_ieee11073_from_float(float temperature);
gkroussos 0:dd0fea342ad2 34 void updateTemp(void);
gkroussos 0:dd0fea342ad2 35
gkroussos 0:dd0fea342ad2 36 class GapEventHandler : public GapEvents {
gkroussos 0:dd0fea342ad2 37 // When a client device connects we need to turn off the advertising LED
gkroussos 0:dd0fea342ad2 38 virtual void onConnected(void){
gkroussos 0:dd0fea342ad2 39 adStateLed = 0;
gkroussos 0:dd0fea342ad2 40 }
gkroussos 0:dd0fea342ad2 41
gkroussos 0:dd0fea342ad2 42 // When a client device disconnects we need to start advertising again
gkroussos 0:dd0fea342ad2 43 virtual void onDisconnected(void) {
gkroussos 0:dd0fea342ad2 44 nrf.getGap().startAdvertising(advParams);
gkroussos 0:dd0fea342ad2 45 adStateLed = 1;
gkroussos 0:dd0fea342ad2 46 }
gkroussos 0:dd0fea342ad2 47 };
gkroussos 0:dd0fea342ad2 48
gkroussos 0:dd0fea342ad2 49
gkroussos 0:dd0fea342ad2 50 int main(void){
gkroussos 0:dd0fea342ad2 51
gkroussos 0:dd0fea342ad2 52 // Start the one second ticker
gkroussos 0:dd0fea342ad2 53 oneSec.attach(updateTemp, 1);
gkroussos 0:dd0fea342ad2 54
gkroussos 0:dd0fea342ad2 55 nrf.getGap().setEventHandler(new GapEventHandler());
gkroussos 0:dd0fea342ad2 56
gkroussos 0:dd0fea342ad2 57 // Start the BLE radio
gkroussos 0:dd0fea342ad2 58 nrf.init();
gkroussos 0:dd0fea342ad2 59 nrf.reset();
gkroussos 0:dd0fea342ad2 60
gkroussos 0:dd0fea342ad2 61 // Add GAP data, but don't start advertising
gkroussos 0:dd0fea342ad2 62 advData.addFlags((GapAdvertisingData::Flags)(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE));
gkroussos 0:dd0fea342ad2 63 advData.addData(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t*)deviceName, sizeof(deviceName));
gkroussos 0:dd0fea342ad2 64 advData.addAppearance(GapAdvertisingData::GENERIC_THERMOMETER);
gkroussos 0:dd0fea342ad2 65 nrf.getGap().setAdvertisingData(advData, scanResponse);
gkroussos 0:dd0fea342ad2 66
gkroussos 0:dd0fea342ad2 67 // Temperature Sensor Service
gkroussos 0:dd0fea342ad2 68 // Add the characteristic to the tempSensorService and add the service to the GATT server
gkroussos 0:dd0fea342ad2 69 // <Write your code here>
gkroussos 0:dd0fea342ad2 70
gkroussos 0:dd0fea342ad2 71 // Finally start advertising (can't start advertising before all services are added)
gkroussos 0:dd0fea342ad2 72 nrf.getGap().startAdvertising(advParams);
gkroussos 0:dd0fea342ad2 73 adStateLed = 1;
gkroussos 0:dd0fea342ad2 74
gkroussos 0:dd0fea342ad2 75 while(1){
gkroussos 0:dd0fea342ad2 76 }
gkroussos 0:dd0fea342ad2 77 }
gkroussos 0:dd0fea342ad2 78
gkroussos 0:dd0fea342ad2 79 // Update temperature
gkroussos 0:dd0fea342ad2 80 void updateTemp(void){
gkroussos 0:dd0fea342ad2 81 oneSecLed = !oneSecLed;
gkroussos 0:dd0fea342ad2 82
gkroussos 0:dd0fea342ad2 83 probe.convertTemperature(true, DS1820::all_devices); // initialise DS1820 digital temperature sensor
gkroussos 0:dd0fea342ad2 84 float temperature = probe.temperature(); // obtain reading
gkroussos 0:dd0fea342ad2 85 //float temperature = ((LM35*3.3)-0.600)*100.0; // for use with analog LM35 sensor from Maplin
gkroussos 0:dd0fea342ad2 86 uint32_t temp_ieee11073 = quick_ieee11073_from_float(temperature);
gkroussos 0:dd0fea342ad2 87 memcpy(tempSensorPayload+1, &temp_ieee11073, 4);
gkroussos 0:dd0fea342ad2 88 nrf.getGattServer().updateValue(tempSensorChar.handle, tempSensorPayload, sizeof(tempSensorPayload));
gkroussos 0:dd0fea342ad2 89 }
gkroussos 0:dd0fea342ad2 90
gkroussos 0:dd0fea342ad2 91 // Quick conversion to an IEEE11073 format
gkroussos 0:dd0fea342ad2 92 uint32_t quick_ieee11073_from_float(float temperature){
gkroussos 0:dd0fea342ad2 93 uint8_t exponent = 0xFF;
gkroussos 0:dd0fea342ad2 94 uint32_t mantissa = (uint32_t)(temperature*10);
gkroussos 0:dd0fea342ad2 95 return ( ((uint32_t)exponent) << 24) | mantissa;
gkroussos 0:dd0fea342ad2 96 }
gkroussos 0:dd0fea342ad2 97