main.cpp

00001 #include "mbed.h"
00002 #include "BLEPeripheral.h"
00003 
00004 //serial connection via USB 
00005 Serial serial(USBTX, USBRX);
00006 
00007 //Declare Input and Output pins
00008 DigitalIn pb(D3);
00009 AnalogIn pH_sensor(A0);
00010 InterruptIn button(D2); 
00011 DigitalOut led(LED_RED);
00012 
00013 // The SPI construct, REQN and RDYN IO construct should be modified manually
00014 // It depend on the board you are using and the REQN&RDYN configuration on BLE Shield
00015 SPI spi(PTD2, PTD3, PTD1);      
00016 DigitalInOut BLE_RDY(PTD5);  
00017 DigitalInOut BLE_REQ(PTD0); 
00018 DigitalInOut BLE_RESET(PTA13);
00019 
00020 //for BLE
00021 int count = 0;
00022 unsigned char tempbuf[16] = {0};
00023 unsigned char templen = 0;
00024 unsigned char decbuf[16] = {0};
00025 unsigned char declen = 0;
00026 unsigned char pHbuf[16] = {0};
00027 unsigned char pHlen = 0;
00028 
00029 /*----- BLE Utility -------------------------------------------------------------------------*/
00030 // create peripheral instance, see pinouts above
00031 BLEPeripheral            blePeripheral        = BLEPeripheral(&BLE_REQ, &BLE_RDY, NULL);
00032  
00033 // create service
00034 BLEService               uartService          = BLEService("713d0000503e4c75ba943148f18d941e");
00035  
00036 // create characteristic
00037 BLECharacteristic    txCharacteristic = BLECharacteristic("713d0002503e4c75ba943148f18d941e", BLENotify, 30, 0);
00038 BLECharacteristic    rxCharacteristic = BLECharacteristic("713d0003503e4c75ba943148f18d941e", BLENotify, 20, 1);
00039 /*--------------------------------------------------------------------------------------------*/
00040 unsigned int interval = 0;
00041 unsigned char count_on = 0;
00042 
00043 //for pH measurement
00044 int calib = 0;
00045 int avgReading = 0;
00046 bool calibrationORnot = true;
00047 bool ready = false;
00048 int* reading[] = {0,0};
00049 
00050 
00051 //This loop takes a reading by taking 15 measurements and averaging them when it is called in the loop "measure"
00052 int takeReading()
00053 {
00054     double totalVal = 0.0;
00055     double pH_sensor_read = 0.0;
00056     int totalReadings = 0;
00057     while(totalReadings < 16){
00058         pH_sensor_read = pH_sensor.read();
00059         totalVal = totalVal + pH_sensor_read;
00060         totalReadings++;
00061         }
00062     int avgSensor = totalVal/15;      
00063     return avgSensor;
00064  }
00065 
00066 void calibration()
00067 {
00068     //serial.printf("enter calibration loop\n");
00069     //Loop to take calibration value
00070     calib = takeReading();
00071     //serial.printf("calib is %d\n", calib);
00072 }
00073 
00074 void calculate()
00075 {
00076     //serial.printf("entered calc\n");
00077     //Take average of readings over 10 seconds        
00078     avgReading = takeReading();
00079     //serial.printf("took reading\n");
00080     ready = true;
00081 }
00082 
00083 void measure()
00084 {
00085     serial.baud(115200);
00086     //serial.printf("start measurement");
00087     //cb.mode(PullUp);
00088     if(calibrationORnot)
00089     {
00090         calibration();
00091         calibrationORnot = !calibrationORnot;
00092     }    
00093 //Loop to take measurement        
00094     else if(!calibrationORnot) 
00095     {
00096     //  serial.printf("enter measurement loop\n");
00097      //   serial.printf("calib is %d\n", calib);
00098         calculate();
00099     }
00100 }
00101 
00102 
00103 int main()
00104 { 
00105     pb.mode(PullUp);
00106     serial.baud(115200);
00107     serial.printf("Hello SmartD!\n");
00108     serial.printf("Serial begin!\r\n");
00109     float pH,yint,tempC,tempF;
00110 
00111      /*----- BLE Utility ---------------------------------------------*/
00112     // set advertised local name and service UUID
00113     blePeripheral.setLocalName("Sita");
00114     
00115     blePeripheral.setAdvertisedServiceUuid(uartService.uuid());
00116         
00117     // add service and characteristic
00118     blePeripheral.addAttribute(uartService);
00119     blePeripheral.addAttribute(rxCharacteristic);
00120     blePeripheral.addAttribute(txCharacteristic);
00121 
00122     // begin initialization
00123     blePeripheral.begin();
00124     /*---------------------------------------------------------------*/
00125 
00126     //serial.printf("GOT IT pH is %d, Temp is %d\n\r", reading[0], reading[1]);    
00127     serial.printf("\nBLE UART Peripheral begin!\r\n");
00128     if (calibrationORnot)
00129     {    
00130         button.rise(&measure);
00131     }
00132     
00133     while(1)
00134     {
00135         BLECentral central = blePeripheral.central();
00136         if (ready) 
00137         {
00138             //calcuating yintercept of the ADC -> pH equation using calibration value and given that calibration liquid is pH4
00139             yint = (68.97*calib)-4;
00140             //serial.printf("yint is %f", yint);
00141             //assumes linear relationship between pin readout -> voltage ->pH
00142             pH = (0.0209*3300)*(avgReading)-yint;
00143             //conversion to degrees C from sensor output voltage
00144             tempC = (((3000*avgReading/1000) - 1.022129)/-0.0018496);
00145             tempF = (tempC *9/5) + 32;
00146             //print current pH and temp
00147             serial.printf("pH = %f & temp = %f F\n\r", pH, tempF);
00148             ready = !ready;
00149         }
00150         
00151         if (central) 
00152         {
00153             // central connected to peripheral
00154             serial.printf("Connected to central\r\n");
00155             while (central.connected()) 
00156             {
00157                 if(!pb)
00158                 {
00159                     tempF = 98.5;
00160                     int tempint = tempF;
00161                     int tempdecimal = (tempF-tempint)*100;
00162                     int pHint = pH;
00163                     int pHdecimal = (pH-pHint)*100;                    
00164 //                    int tempint = 20;
00165 //                    int tempdecimal = 23;
00166 //                    int pHint = 9;
00167                     tempbuf[0]= tempint;
00168                     tempbuf[1] = tempdecimal;
00169                     //tempbuf[templen] = tempint;
00170                     //decbuf[declen] = decimal;
00171                     pHbuf[0] = pHint;
00172                     pHbuf[1] = pHdecimal;
00173                     interval++;
00174                 }
00175 
00176                 if(interval == 1) 
00177                 { // If there is no char available last the interval, send the received chars to central.
00178                     //serial.printf("Received from terminal: %d bytes\r\n", templen);
00179                     txCharacteristic.setValue((const unsigned char *)tempbuf, 2);
00180                     txCharacteristic.setValue((const unsigned char *)pHbuf, 2);
00181                     serial.printf("done");
00182                     wait(2);
00183                     interval = 0;
00184                 }
00185             }
00186             // central disconnected
00187             serial.printf("Disconnected from central\r\n");
00188         }
00189     }
00190 }