I want to show three decimals for my fluid flow sensor

Hey guys,

I am a little bit confused. I would like to adjust the flowing code in order to get three decimals of fluid flow rate. I am using yf-s401 flow sensor. The code that I am using is below:

`
int sensorInterrupt = 0; // interrupt 0
int sensorPin = 2; //Digital Pin 2
int solenoidValve = 5; // Digital pin 5
unsigned int SetPoint = 400; //400 milileter

/The hall-effect flow sensor outputs pulses per second per litre/minute of flow./
float calibrationFactor = 90; //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(solenoidValve , OUTPUT);
digitalWrite(solenoidValve, HIGH);
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 > 40)
{
  SetSolinoidValve();
}

`

Thank you.

What part of that is not working?

1 Like

Are you looking for this?

Serial.print(flowRate, 3);  // Print 3 decimal places.
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Note the sensor is only accurate to +- 3% , over the range .3 to 3 litre/min , so that extra place may well be meaningless

A flow rate 1.001 litre/min could be anywhere between 1.09 and 0.92 litre /min

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Your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advice on) your project :wink: See About the IDE 1.x category.

I think that Serial.print() - Arduino Reference will give you the answer.

1 Like

Thank you all for the nice comments. Serial.print(flowRate, 3) worked really well.

Good to hear.

Perhaps you can mark the most helpful post as the solution then? This prevents helpers spending time on a solved issue and it will lead people with the same question to the correct answer directly.

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