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Hydroponics measurement system for Arduino
/*
* Hydroponics system monitor
* J. Devine
* Runs on Arduino Pro 5V
* Sensors:
* DFRobot pHmeter V1.1
* 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), 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
* Pin 12 - HC-SR04 Trig
* 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
*
* Licensed under GPL V3. Read the license here:
* https://www.gnu.org/licenses/gpl-3.0.en.html
*
*/
#define SensorPin A2 //pH meter Analog output to Arduino Analog Input 2
#define Offset 0.00 //deviation compensate
//#define LED 13
#define samplingInterval 20
#define printInterval 800
#define ArrayLenth 40 //times of collection
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.
OneWire ds(10); // on pin 10
int echopin = 13;
int trigpin = 12;
int vcc = 11;
long duration, distance;
//tmp36 readout
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);
Serial.begin(9600);
// Serial.println("pH meter experiment!"); //Test the serial monitor
}
void loop(void)
{
static unsigned long samplingTime = millis();
static unsigned long printTime = millis();
static float pHValue,voltage;
if(millis()-samplingTime > samplingInterval)
{
pHArray[pHArrayIndex++]=analogRead(SensorPin);
if(pHArrayIndex==ArrayLenth)pHArrayIndex=0;
voltage = avergearray(pHArray, ArrayLenth)*5.0/1024;
pHValue = 3.5*voltage+Offset;
samplingTime=millis();
}
if(millis() - printTime > printInterval) //Every 800 milliseconds, print a numerical, convert the state of the LED indicator
{
// Serial.print("Voltage:");
// Serial.print(voltage,2);
// Serial.print(" pH value: ");
// Serial.println(pHValue,2);
// digitalWrite(LED,digitalRead(LED)^1);
printTime=millis();
}
byte i;
byte present = 0;
byte data[12];
byte addr[8];
int Temp;
ds.reset_search();
if ( !ds.search(addr)) {
// Serial.print("No more addresses.\n");
ds.reset_search();
return;
}
// Serial.print("R=");
for( i = 0; i < 8; i++) {
// Serial.print(addr[i], HEX);
// Serial.print(" ");
}
if ( OneWire::crc8( addr, 7) != addr[7]) {
// Serial.print("CRC is not valid!\n");
return;
}
if ( addr[0] == 0x10) {
// Serial.print("Device is a DS18S20 family device.\n");
}
else if ( addr[0] == 0x28) {
// Serial.print("Device is a DS18B20 family device.\n");
}
else {
// Serial.print("Device family is not recognized: 0x");
// Serial.println(addr[0],HEX);
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
delay(1000); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
// Serial.print("P=");
// Serial.print(present,HEX);
// Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
// Serial.print(data[i], HEX);
// Serial.print(" ");
}
Temp=(data[1]<<8)+data[0];//take the two bytes from the response relating to temperature
// Serial.println("One, then 0");
// Serial.println(data[1]); //msb
// Serial.println(data[0]); //lsb
//Temp=Temp>>4;//divide by 16 to get pure celcius readout
Ftemp =(Temp * 0.0625);
//next line is Fahrenheit conversion
//Temp=Temp*1.8+32; // comment this line out to get celcius
// Serial.print("T=");//output the temperature to serial port
// Serial.print(Temp);
// Serial.print(" ");
//Serial.print(" fT=");//output the temperature to serial port
// Serial.print(Ftemp);
// Serial.print(" ");
// Serial.print(" CRC=");
// Serial.print( OneWire::crc8( data, 8), HEX);
// Serial.println();
//getting the voltage reading from the temperature sensor
int reading = analogRead(sensorPin);
// converting that reading to voltage, for 3.3v arduino use 3.3
float ATvoltage = reading * 5.0;
ATvoltage /= 1024.0;
// print out the voltage
//Serial.print(ATvoltage); Serial.println(" volts");
// now print out the temperature
float temperatureC = (ATvoltage - 0.5) * 100 ; //converting from 10 mv per degree wit 500 mV offset
//to degrees ((voltage - 500mV) times 100)
//Serial.print(temperatureC); Serial.println(" degrees C");
// now convert to Fahrenheit
//float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;
//Serial.print(temperatureF); Serial.println(" degrees F");
//delay(1000);
digitalWrite(trigpin, LOW); // Added this line
delayMicroseconds(4); // Added this line
digitalWrite(trigpin, HIGH);
delayMicroseconds(20); // Added this line
digitalWrite(trigpin, LOW);
duration = pulseIn(echopin, HIGH);
distance = (duration/2) / 29.1;
Serial.print(millis());
Serial.print(';');
Serial.print(distance);
// if (distance >= 200 || distance <= 0){
// Serial.println("Out of range");
//}
//else {
//Serial.print(distance);
//Serial.println(" cm");
// }
//delay(500);
//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), RC, EC, PPM
Serial.print(';');
Serial.print(pHValue,2);
Serial.print(';');
Serial.print(voltage,2);
Serial.print(';');
Serial.print(Ftemp);
Serial.print(';');
Serial.print(temperatureC);
Serial.print(';');
GetEC();
PrintReadings();
delay(5000);
}
double avergearray(int* arr, int number){
int i;
int max,min;
double avg;
long amount=0;
if(number<=0){
Serial.println("Error number for the array to avraging!/n");
return 0;
}
if(number<5){ //less than 5, calculated directly statistics
for(i=0;i<number;i++){
amount+=arr[i];
}
avg = amount/number;
return avg;
}else{
if(arr[0]<arr[1]){
min = arr[0];max=arr[1];
}
else{
min=arr[1];max=arr[0];
}
for(i=2;i<number;i++){
if(arr[i]<min){
amount+=min; //arr<min
min=arr[i];
}else {
if(arr[i]>max){
amount+=max; //arr>max
max=arr[i];
}else{
amount+=arr[i]; //min<=arr<=max
}
}//if
}//for
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(';');
}
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