main.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016  
00017 #define TARGET_NRF_LFCLK_RC 1
00018 
00019 #include "mbed.h"
00020 #include "BLE.h"
00021 #include "UberVestService.h"
00022 #include <math.h>
00023 
00024 // BEGIN IO
00025 // Inputs and outputs need to be changed between the devkit and prospeckz
00026 
00027 // Outputs
00028 DigitalOut connectionLed(LED1);
00029 
00030 // Inputs
00031 AnalogIn ecg(p6);
00032 AnalogIn temp(p2);
00033 
00034 // N.B. The devkit and prospeckz are different - DK is active low, prospeckz is active high.
00035 static const bool LED_ON = 1;
00036 static const bool LED_OFF = 0;
00037 
00038 // END IO
00039 
00040 Serial pc(USBTX, USBRX);
00041 BLE ble;
00042 
00043 const static char     DEVICE_NAME[] = "UberVest";
00044 static const uint16_t uuid16_list[] = {UberVestService::UBER_VEST_SERVICE_UUID};
00045 
00046 static int8_t ecgValue;
00047 static int8_t tempValue;
00048 
00049 static volatile bool sampleEcg = false;
00050 static volatile bool sampleTemp = false;
00051 
00052 UberVestService *uberVestServicePtr;
00053 
00054 void connectionCallback(const Gap::ConnectionCallbackParams_t *params)
00055 {
00056     connectionLed = LED_OFF;
00057 }
00058 
00059 void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
00060 {
00061     ble.gap().startAdvertising();
00062     connectionLed = LED_ON;
00063 }
00064 
00065 void sampleEcgCallback(void)
00066 {
00067     sampleEcg = true;
00068 }
00069 
00070 void sampleTempCallback(void)
00071 {
00072     sampleTemp = true;
00073 }
00074 
00075 void flasherTimer(void)
00076 {
00077     if (!ble.getGapState().connected) {
00078         connectionLed = !connectionLed;
00079     }
00080 }
00081 
00082 float getTemp(void)
00083 {
00084     const int TEMP_RESISTOR_VALUE = 10900;
00085     float rawValue;
00086     float r; // Thermistor resistance
00087     double convertedTemp;
00088     
00089     rawValue = temp.read();
00090     // The thermistor is set up as a simple voltage divider. We can get the resistance as follows:
00091     r = ((TEMP_RESISTOR_VALUE * 5.0f) / (rawValue * 4.3f)) - TEMP_RESISTOR_VALUE;
00092     
00093     // Now calculate the temperature from the resistance
00094     // From the thermistor data sheet (http://www.farnell.com/datasheets/1784420.pdf):
00095     const float R_REF = 10000.0f;
00096     const double A = 3.354016e-03;
00097     const double B = 2.569850e-04;
00098     const double C = 2.620131e-06;
00099     const double D = 6.383091e-08;
00100     
00101     convertedTemp = A + B * (log(r / R_REF)) + C * pow(log(r / R_REF), 2.0f) + D * pow(log(r / R_REF), 3.0f);
00102     convertedTemp = 1.0f / convertedTemp;
00103     
00104     // convert to degrees celsius:
00105     convertedTemp = convertedTemp - 273.0f;
00106     
00107     pc.printf("Raw: %f, Resisance: %f, Temp: %f\r\n", rawValue, r, convertedTemp);
00108     
00109     return (float) convertedTemp;
00110 }
00111     
00112 int main(void)
00113 {
00114     ble.init();
00115     ble.gap().onConnection(connectionCallback);
00116     ble.gap().onDisconnection(disconnectionCallback);
00117     
00118     ecgValue = 0;
00119     tempValue = 0;
00120 
00121     UberVestService uberVestService(ble, ecgValue, tempValue);
00122     uberVestServicePtr = &uberVestService;
00123     
00124     Ticker ecgSampler;
00125     ecgSampler.attach(sampleEcgCallback, 0.02);
00126     
00127     Ticker tempSampler;
00128     tempSampler.attach(sampleTempCallback, 1);
00129     
00130     Ticker flasher;
00131     flasher.attach(flasherTimer, 0.5);
00132 
00133     /* setup advertising */
00134     ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
00135     ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list));
00136     ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
00137     ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
00138     ble.gap().setAdvertisingInterval(1000); /* 1000ms. */
00139     ble.gap().startAdvertising();
00140 
00141     while (true) {
00142         if (ble.getGapState().connected) {
00143             if (sampleEcg) {
00144                 sampleEcg = false;
00145                 
00146                 ecgValue = (ecg.read() * 512);
00147                 uberVestServicePtr->updateEcg(ecgValue);
00148             }
00149             
00150             if (sampleTemp) {
00151                 sampleTemp = false;
00152                 
00153                 tempValue = getTemp();
00154                 uberVestServicePtr->updateTemp(tempValue);
00155             }
00156         } else {
00157             ble.waitForEvent();
00158         }
00159     }
00160 }