//soil moisture sensor #define soilMoisture A0 //connect analog pin of soil moisture sensor to A0 of Arduino #define reqpercent 30//start flow if moisture is less than 30 percent //calibration //maximum value detected(dry) 1025 //minimum value detected(wet) 10 //percentage of moisture= 100-(detected/maximum*100) //100/maximum=100/1025=0.0975 unsigned long moisture; float percentage; //flow sensor #define flowSensor 2//connect data pin of flow sensor to D2 of Arduino #define reqWater 2000//flow is stopped after 2000 mL byte sensorInterrupt = 0; // The hall-effect flow sensor outputs approximately 7.5 pulses per second per // litre/minute of flow. float calibrationFactor = 7.5; volatile byte pulseCount; float flowRate; unsigned int flowMilliLitres; unsigned long totalMilliLitres; unsigned long oldTime; //relay #define relay 8//connect data pin of relay to D8 of Arduino void setup() { // Initialize a serial connection for reporting values to the host Serial.begin(115200); pinMode(soilMoisture,INPUT); pinMode(flowSensor, INPUT); digitalWrite(flowSensor, HIGH); pulseCount = 0; flowRate = 0.0; flowMilliLitres = 0; totalMilliLitres = 0; oldTime = 0; moisture =0; percentage=100; attachInterrupt(sensorInterrupt, pulseCounter, FALLING); pinMode(relay, OUTPUT); pinMode(relay,LOW);//off } void loop() { if(flowRate<0)//read soil moisture only when no flow { totalMilliLitres = 0;//reset moisture=analogRead(soilMoisture);//read input from pin A0(soilMoisture) Serial.print("Moisture: "); Serial.print(moisture); Serial.print("\t"); percentage=100-(moisture*0.0975);//express as a percentage Serial.print("Percentage: "); Serial.print(percentage); Serial.println("%"); delay(3000); } if(percentage<=reqpercent)//start flow if soil moisture is lesser than 30 percent { if((millis() - oldTime) > 1000) // Only process counters once per second { // Disable the interrupt while calculating flow rate and sending the value to // the host detachInterrupt(sensorInterrupt); // Because this loop may not complete in exactly 1 second intervals we calculate // the number of milliseconds that have passed since the last execution and use // that to scale the output. We also apply the calibrationFactor to scale the output // based on the number of pulses per second per units of measure (litres/minute in // this case) coming from the sensor. flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor; // Note the time this processing pass was executed. Note that because we've // disabled interrupts the millis() function won't actually be incrementing right // at this point, but it will still return the value it was set to just before // interrupts went away. oldTime = millis(); // Divide the flow rate in litres/minute by 60 to determine how many litres have // passed through the sensor in this 1 second interval, then multiply by 1000 to // convert to millilitres. flowMilliLitres = (flowRate / 60) * 1000; // Add the millilitres passed in this second to the cumulative total totalMilliLitres += flowMilliLitres; unsigned int frac; // Print the flow rate for this second in litres / minute Serial.print("Flow rate: "); Serial.print(int(flowRate)); // Print the integer part of the variable Serial.print("L/min"); Serial.print("\t"); // Print tab space // Print the cumulative total of litres flowed since starting Serial.print("Output Liquid Quantity: "); Serial.print(totalMilliLitres); Serial.println("mL"); // Reset the pulse counter so we can start incrementing again pulseCount = 0; // Enable the interrupt again now that we've finished sending output attachInterrupt(sensorInterrupt, pulseCounter, FALLING); } } if(totalMilliLitres>reqWater) { digitalWrite(relay, LOW); //off delay(2000); // wait for a second } else { digitalWrite(relay, HIGH); // on delay(2000) // wait for a second } } void pulseCounter() { // Increment the pulse counter pulseCount++; } long microsecondsToCentimeters (long microseconds) { return microseconds /29 /2; }