Hydroponicsmeasure.ino

@@ -7,15 +7,20 @@
  * Waterproof DS18B20 water temperature sensor
  * TMP36 air temperature sensor
  * HC-SR04 distance sensor (for water level..)
+ * A european two pin plug for EC measurements
  * Output in CSV; no error handling yet
  * write out all the results in the following format:
- * uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C)
+ * uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C), RC, EC, PPM
  * 
  * This code is entirely based on some awesome examples, re-worked for this application
  * The internal pullup library is needed to avoid an external 4.7k resistor on the DS18B20
  * Great blog entry by josh levine @bigjoshlevine - Thanks! I was thinking EXACTLY the same thing
  * https://wp.josh.com/2014/06/23/no-external-pull-up-needed-for-ds18b20-temp-sensor/
  * 
+ * PPM code
+ * Modified from ElCheapo Arduino EC-PPM measurments
+ * 28/8/2015  Michael Ratcliffe  Mike@MichaelRatcliffe.com
+ * 
  * Pinouts:
  * 
  * Pin 10 - DS18B20 data pin
@@ -23,11 +28,10 @@
  * Pin 13 - HC-SR04 Echo
  * Pin A2 - pH Meter V1.1 data (DF Robot breakout)
  * Pin A3 - TMP36 data pin
+ * Pin D4 - EC/PPM Power
+ * Pin A1 - EC/PPM Pin
+ * Pin A3 - EC/PPM Ground
  * 
- * As a reminder to myself, I used pin PA6 on the OrangePiZero that I'm hosting this on for reset (active low)
- * on the Arduino Pro Mini, there is also a 3v3/5v potential divider on the TX from the Arduino.
- * The Orange Pi Zero UART being used is UART1
- *
  * Licensed under GPL V3. Read the license here:
  * https://www.gnu.org/licenses/gpl-3.0.en.html
  * 
@@ -41,6 +45,35 @@
 int pHArray[ArrayLenth];   //Store the average value of the sensor feedback
 int pHArrayIndex=0;    
 
+//PPM code
+// Modified from ElCheapo Arduino EC-PPM measurments
+//  28/8/2015  Michael Ratcliffe  Mike@MichaelRatcliffe.com
+int R1= 400;
+int Ra=25; //Resistance of powering Pins
+int ECPin= A1;
+int ECGround=A3;
+int ECPower = 4;
+
+//User variales for the PPM/EC measurement
+float PPMconversion=0.7;
+float TemperatureCoef = 0.019; //this changes depending on what chemical we are measuring
+float K=2.85;
+//Fixed variables
+//float Temperature=10; variable substituted for Ftemp in this code
+float EC=0;
+float EC25 =0;
+int ppm =0;
+float raw= 0;
+float Vin= 5;
+float Vdrop= 0;
+float Rc= 0;
+float buffer=0;
+
+//water temperature
+float Ftemp=10;
+
+ 
+
 // DS18S20 Temperature chip i/o
 #include <OneWire.h> //this is the onewire version with the pullup high.
 
@@ -57,6 +90,20 @@ int sensorPin = 0;
 
 void setup(void)
 {
+  //PPM Measurement setup code
+  pinMode(ECPin,INPUT);
+  pinMode(ECPower,OUTPUT);//Setting pin for sourcing current
+  pinMode(ECGround,OUTPUT);//setting pin for sinking current
+  digitalWrite(ECGround,LOW);//We can leave the ground connected permanantly
+ 
+  delay(100);// gives sensor time to settle
+  delay(100);
+  //** Adding Digital Pin Resistance to [25 ohm] to the static Resistor *********//
+  // Consule Read-Me for Why, or just accept it as true
+  R1=(R1+Ra);// Taking into acount Powering Pin Resitance
+
+
+  
   pinMode(echopin, INPUT);     
   pinMode(trigpin, OUTPUT);     
 //  pinMode(LED,OUTPUT);  
@@ -93,7 +140,7 @@ void loop(void)
   byte data[12];
   byte addr[8];
   int Temp;
-  float Ftemp;
+
   ds.reset_search();
   if ( !ds.search(addr)) {
   //    Serial.print("No more addresses.\n");
@@ -224,7 +271,7 @@ Ftemp =(Temp * 0.0625);
 
 
 //write out all the results in the following format
-// uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C)
+// uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C), RC, EC, PPM
 
 
 
@@ -236,7 +283,10 @@ Serial.print(';');
 Serial.print(Ftemp);
 Serial.print(';');
 Serial.print(temperatureC);
-Serial.println(';');
+Serial.print(';');
+GetEC();
+PrintReadings();    
+delay(5000);
 }
 
 
@@ -280,4 +330,49 @@ double avergearray(int* arr, int number){
     avg = (double)amount/(number-2);
   }//if
   return avg;
-}
+}
+
+void GetEC(){
+ 
+ 
+ 
+//************Estimates Resistance of Liquid ****************//
+digitalWrite(ECPower,HIGH);
+raw= analogRead(ECPin);
+raw= analogRead(ECPin);// This is not a mistake, First reading will be low beause if charged a capacitor
+digitalWrite(ECPower,LOW);
+ 
+ 
+ 
+ 
+//***************** Converts to EC **************************//
+Vdrop= (Vin*raw)/1024.0;
+Rc=(Vdrop*R1)/(Vin-Vdrop);
+Rc=Rc-Ra; //acounting for Digital Pin Resitance
+EC = 1000/(Rc*K);
+ 
+ 
+//*************Compensating For Temperaure********************//
+EC25  =  EC/ (1+ TemperatureCoef*(Ftemp-25.0));
+ppm=(EC25)*(PPMconversion*1000);
+ 
+ 
+;}
+//************************** End OF EC Function ***************************//
+ 
+ 
+ 
+ 
+//***This Loop Is called From Main Loop- Prints to serial usefull info ***//
+void PrintReadings(){
+//Serial.print("Rc: ");
+Serial.print(Rc);
+Serial.print(';');
+//Serial.print(" EC: ");
+Serial.print(EC25);
+Serial.print(';');
+//Serial.print(" Simens  ");
+Serial.print(ppm);
+//Serial.print(" ppm  "); 
+Serial.println(';');
+}