I’m totally new to Arduino and code, I would appreciate some help.
This code activates a relay (pin 5) if the flow count reaches 400 milliliters.
If the flow stops before 400 milliliters is reached, what is needed to reset the pulse counter to zero to start over.
int sensorInterrupt = 0; // interrupt 0
int sensorPin = 2; //Digital Pin 2 // using this design https://www.bc-robotics.com/tutorials/using-a-flow-sensor-with-arduino/
int Relay = 5; // Digital pin 5 // Using SRD--T73_PDF
unsigned int SetPoint = 400; //400 milileter
/*The hall-effect flow sensor outputs pulses per second per litre/minute of flow.*/
float calibrationFactor = 4.5; //You can change according to your datasheet
volatile byte pulseCount =0;
float flowRate = 0.0;
unsigned int flowMilliLitres =0;
unsigned long totalMilliLitres = 0;
unsigned long oldTime = 0;
void setup()
{
// Initialize a serial connection for reporting values to the host
Serial.begin(9600);
pinMode(Relay , OUTPUT);
pinMode(sensorPin, INPUT);
digitalWrite(sensorPin, HIGH);
/*The Hall-effect sensor is connected to pin 2 which uses interrupt 0. Configured to trigger on a FALLING state change (transition from HIGH
(state to LOW state)*/
attachInterrupt(sensorInterrupt, pulseCounter, FALLING); //you can use Rising or Falling
}
void loop()
{
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(flowMilliLitres, DEC); // Print the integer part of the variable
Serial.print("mL/Second");
Serial.print("\t");
// Print the cumulative total of litres flowed since starting
Serial.print("Output Liquid Quantity: ");
Serial.print(totalMilliLitres,DEC);
Serial.println("mL");
Serial.print("\t");
if (totalMilliLitres > 400)
{
SetRelay ();
}
// 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);
}
}
//Insterrupt Service Routine
void pulseCounter()
{
// Increment the pulse counter
pulseCount++;
}
void SetRelay()
{
digitalWrite(Relay, HIGH);
}