Bluetooth Low Energy / Mbed 2 deprecated BLE_Thermometer Featured

BLE demo for the Health-Thermometer service.

Dependencies:   BLE_API mbed nRF51822 X_NUCLEO_IDB0XA1

This example demonstrates how to use the Health Thermometer Service. The Health Thermometer service reports two pieces of information, Temperature and Sensor Location.

API

Import library
BLE_API - HealthThermometerService Class Reference

Public Types

enum SensorLocation_t {
LOCATION_ARMPIT = 1, LOCATION_BODY , LOCATION_EAR , LOCATION_FINGER ,
LOCATION_GI_TRACT , LOCATION_MOUTH , LOCATION_RECTUM , LOCATION_TOE ,
LOCATION_EAR_DRUM
}

Public Member Functions

HealthThermometerService ( BLE &_ble, float initialTemp, uint8_t _location)
Add the Health Thermometer Service to an existing BLE object, initialize with temperature and location.
void updateTemperature (float temperature)
Update the temperature being broadcast.
void updateLocation ( SensorLocation_t loc)
Update the location.

Technical Details

Further Technical Details can be found at the following links

Files at this revision

API Documentation at this revision

Revision 3:8733f3e50c84, committed 2014-09-04

Comitter:
rgrover1
Date:
Thu Sep 04 07:14:25 2014 +0000
Parent:
2:a34d554282b0
Child:
4:83c07b0e93d6
Commit message:
use ieee11073_from_float to encode temperature correctly.

Changed in this revision

HealthThermometerService.h Show annotated file Show diff for this revision Revisions of this file 
--- a/HealthThermometerService.h	Wed Sep 03 16:25:50 2014 +0000
+++ b/HealthThermometerService.h	Thu Sep 04 07:14:25 2014 +0000
@@ -89,7 +89,8 @@
         }
 
         void updateTemperature(float temp) {
-            memcpy(&bytes[OFFSET_OF_VALUE], &temp, sizeof(float));
+            uint32_t temp_ieee11073 = quick_ieee11073_from_float(temp);
+            memcpy(&bytes[OFFSET_OF_VALUE], &temp_ieee11073, sizeof(float));
         }
 
         uint8_t *getPointer(void) {
@@ -101,6 +102,19 @@
         }
 
     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];