Diff: main.cpp

Revision:

3:98adc27dc82d

Parent:

2:46161d8200a2

Child:

4:bc63632c6808

--- a/main.cpp	Thu Feb 26 07:05:14 2015 +0000
+++ b/main.cpp	Tue Mar 31 23:47:27 2015 +0000
@@ -5,36 +5,47 @@
 //serial connection via USB
 Serial pc(USBTX, USBRX); 
 AnalogIn pH_sensor(A0);
-AnalogOut temp_sensor(A2);
+AnalogIn temp_sensor(A1);
  
 
 int main()
 {
+    pc.baud(115200);
     float voltage, pH, tempC, tempF;
     //Power temperature sensor  
-    temp_sensor = 0.00002;
     while(1) {
         //Take average of readings over 10 seconds
         double totalVal = 0.0;
         double pH_sensor_read = 0.0;
+        double totalValtemp = 0.0;
+        double temp_sensor_read = 0.0;
         int totalReadings = 0;
         time_t start = time(NULL);
-        time_t seconds = 10;
+        time_t seconds = 5;
         time_t end = start + seconds;
         while(time(NULL) < end){
             pH_sensor_read = pH_sensor.read();
             totalVal = totalVal + pH_sensor_read;
+            temp_sensor_read = temp_sensor.read();
+            totalValtemp = totalValtemp + temp_sensor_read;
             totalReadings++;
+            
             }
             double avgSensor = totalVal/(double)totalReadings;
+            double avgTemp = totalValtemp/(totalReadings);
         //Hard coded calibration values taken at pH 4 solution to return voltage in mV
-        voltage = avgSensor*(800/.24);
+        //.24 is the pin read out at pH4
+        //800 is mV at ph4
+        //look at the documentation to figure out what readout correlates to what voltage
+        voltage = avgSensor*(3.3);
         //conversion to pH from sensor output voltage per LM61 data sheet
         pH = (0.0209*voltage)-12.696;
         //conversion to degrees C from sensor output voltage
-        tempC = (((voltage/1000) - 0.871481)/-0.0021504);
+        float voltageT = avgTemp*3.3;
+        tempC = (((voltageT/1000) - 1.022129)/-0.0018496);
         tempF = (tempC *9/5) + 32;
         //print current pH and temp
-        pc.printf("pH = %5.2F & temp = %5.2F F\n\r", pH, tempF);            
+        pc.printf("pH = %5.2F at voltage %5.2F V\n\r", pH, voltage);
+        pc.printf("temp = %5.2F F at voltage %5.2F V\n\r", tempF, voltageT);            
     }
 }
\ No newline at end of file