SmartD / Mbed 2 deprecated mbed_pH_test

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Dependencies:   mbed

Fork of mbed_pH225 by SmartD

main.cpp@4:bc63632c6808, 2015-04-02 (annotated)

Committer:
sitakumar
Date:
Thu Apr 02 04:53:05 2015 +0000
Revision:
4:bc63632c6808
Parent:
3:98adc27dc82d
Child:
5:8ec4c03f4079
huzaifa

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sitakumar 0:f610f2c606a8 1 #include "mbed.h"
sitakumar 0:f610f2c606a8 2 #include "time.h"
sitakumar 0:f610f2c606a8 3
sitakumar 0:f610f2c606a8 4 DigitalOut myled(LED1);
sitakumar 0:f610f2c606a8 5 //serial connection via USB
sitakumar 0:f610f2c606a8 6 Serial pc(USBTX, USBRX);
sitakumar 0:f610f2c606a8 7 AnalogIn pH_sensor(A0);
sitakumar 3:98adc27dc82d 8 AnalogIn temp_sensor(A1);
sitakumar 2:46161d8200a2 9
sitakumar 0:f610f2c606a8 10
sitakumar 0:f610f2c606a8 11 int main()
sitakumar 0:f610f2c606a8 12 {
sitakumar 3:98adc27dc82d 13 pc.baud(115200);
sitakumar 0:f610f2c606a8 14 float voltage, pH, tempC, tempF;
sitakumar 2:46161d8200a2 15 //Power temperature sensor
sitakumar 0:f610f2c606a8 16 while(1) {
sitakumar 1:843151144560 17 //Take average of readings over 10 seconds
sitakumar 0:f610f2c606a8 18 double totalVal = 0.0;
sitakumar 0:f610f2c606a8 19 double pH_sensor_read = 0.0;
sitakumar 3:98adc27dc82d 20 double totalValtemp = 0.0;
sitakumar 3:98adc27dc82d 21 double temp_sensor_read = 0.0;
sitakumar 0:f610f2c606a8 22 int totalReadings = 0;
sitakumar 0:f610f2c606a8 23 time_t start = time(NULL);
sitakumar 3:98adc27dc82d 24 time_t seconds = 5;
sitakumar 0:f610f2c606a8 25 time_t end = start + seconds;
sitakumar 0:f610f2c606a8 26 while(time(NULL) < end){
sitakumar 0:f610f2c606a8 27 pH_sensor_read = pH_sensor.read();
sitakumar 0:f610f2c606a8 28 totalVal = totalVal + pH_sensor_read;
sitakumar 3:98adc27dc82d 29 temp_sensor_read = temp_sensor.read();
sitakumar 3:98adc27dc82d 30 totalValtemp = totalValtemp + temp_sensor_read;
sitakumar 0:f610f2c606a8 31 totalReadings++;
sitakumar 3:98adc27dc82d 32
sitakumar 0:f610f2c606a8 33 }
sitakumar 0:f610f2c606a8 34 double avgSensor = totalVal/(double)totalReadings;
sitakumar 3:98adc27dc82d 35 double avgTemp = totalValtemp/(totalReadings);
sitakumar 1:843151144560 36 //Hard coded calibration values taken at pH 4 solution to return voltage in mV
sitakumar 3:98adc27dc82d 37 //.24 is the pin read out at pH4
sitakumar 3:98adc27dc82d 38 //800 is mV at ph4
sitakumar 3:98adc27dc82d 39 //look at the documentation to figure out what readout correlates to what voltage
sitakumar 3:98adc27dc82d 40 voltage = avgSensor*(3.3);
sitakumar 0:f610f2c606a8 41 //conversion to pH from sensor output voltage per LM61 data sheet
sitakumar 4:bc63632c6808 42 pH = (voltage-.60924)/.05226667;
sitakumar 0:f610f2c606a8 43 //conversion to degrees C from sensor output voltage
sitakumar 4:bc63632c6808 44 float voltageT = avgTemp*3.3*1000;
sitakumar 4:bc63632c6808 45 tempC = ((voltageT - 435.49)/-2.93);
sitakumar 0:f610f2c606a8 46 tempF = (tempC *9/5) + 32;
sitakumar 0:f610f2c606a8 47 //print current pH and temp
sitakumar 3:98adc27dc82d 48 pc.printf("pH = %5.2F at voltage %5.2F V\n\r", pH, voltage);
sitakumar 3:98adc27dc82d 49 pc.printf("temp = %5.2F F at voltage %5.2F V\n\r", tempF, voltageT);
sitakumar 0:f610f2c606a8 50 }
sitakumar 0:f610f2c606a8 51 }