// #
// # Editor : YouYou from DFRobot
// # Date : 23.04.2014
// # E-Mail : youyou.yu@dfrobot.com
// # Product name: Analog EC Meter
// # Product SKU : DFR0300
// # Version : 1.0
// # Description:
// # Sample code for testing the EC meter and get the data feedback from the Arduino Serial Monitor.
// # Connection:
// # EC meter output -> Analog pin 1
// # DS18B20 digital pin -> Digital pin 2
// #
#include
#define StartConvert 0
#define ReadTemperature 1
const byte numReadings = 20; //the number of sample times
byte ECsensorPin = A1; //EC Meter analog output,pin on analog 1
byte DS18B20_Pin = 2; //DS18B20 signal, pin on digital 2
unsigned int AnalogSampleInterval=25,printInterval=700,tempSampleInterval=850; //analog sample interval;serial print interval;temperature sample interval
unsigned int readings[numReadings]; // the readings from the analog input
byte index = 0; // the index of the current reading
unsigned long AnalogValueTotal = 0; // the running total
unsigned int AnalogAverage = 0,averageVoltage=0; // the average
unsigned long AnalogSampleTime,printTime,tempSampleTime;
float temperature,ECcurrent;
//Temperature chip i/o
OneWire ds(DS18B20_Pin); // on digital pin 2
void setup() {
// initialize serial communication with computer:
Serial.begin(115200);
// initialize all the readings to 0:
for (byte thisReading = 0; thisReading < numReadings; thisReading++)
readings[thisReading] = 0;
TempProcess(StartConvert); //let the DS18B20 start the convert
AnalogSampleTime=millis();
printTime=millis();
tempSampleTime=millis();
}
void loop() {
/*
Every once in a while,sample the analog value and calculate the average.
*/
if(millis()-AnalogSampleTime>=AnalogSampleInterval)
{
AnalogSampleTime=millis();
// subtract the last reading:
AnalogValueTotal = AnalogValueTotal - readings[index];
// read from the sensor:
readings[index] = analogRead(ECsensorPin);
// add the reading to the total:
AnalogValueTotal = AnalogValueTotal + readings[index];
// advance to the next position in the array:
index = index + 1;
// if we're at the end of the array...
if (index >= numReadings)
// ...wrap around to the beginning:
index = 0;
// calculate the average:
AnalogAverage = AnalogValueTotal / numReadings;
}
/*
Every once in a while,MCU read the temperature from the DS18B20 and then let the DS18B20 start the convert.
Attention:The interval between start the convert and read the temperature should be greater than 750 millisecond,or the temperature is not accurate!
*/
if(millis()-tempSampleTime>=tempSampleInterval)
{
tempSampleTime=millis();
temperature = TempProcess(ReadTemperature); // read the current temperature from the DS18B20
TempProcess(StartConvert); //after the reading,start the convert for next reading
}
/*
Every once in a while,print the information on the serial monitor.
*/
if(millis()-printTime>=printInterval)
{
printTime=millis();
averageVoltage=AnalogAverage*(float)5000/1024;
Serial.print("Analog value:");
Serial.print(AnalogAverage); //analog average,from 0 to 1023
Serial.print(" Voltage:");
Serial.print(averageVoltage); //millivolt average,from 0mv to 4995mV
Serial.print("mV ");
Serial.print("temp:");
Serial.print(temperature); //current temperature
Serial.print("^C EC:");
float TempCoefficient=1.0+0.0185*(temperature-25.0); //temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.0185*(fTP-25.0));
float CoefficientVolatge=(float)averageVoltage/TempCoefficient;
if(CoefficientVolatge<150)Serial.println("No solution!"); //25^C 1413us/cm<-->about 216mv if the voltage(compensate)<150,that is <1ms/cm,out of the range
else if(CoefficientVolatge>3300)Serial.println("Out of the range!"); //>20ms/cm,out of the range
else
{
