Make: Volume 86

circuit turns on, press the sensor down a few

times while it calibrates. I usually put this in my

setup function:

int sensorPin = 0;

int sensorMax, sensorMin;

[...]

void calibrate() {

while (millis() < 5000) { // Wait 5

seconds (5000 milliseconds)

sensorValue = analogRead(0); //

Read your analog value

if (sensorValue > sensorMax) { //

If it is greater than the previous max

value, it is the new highest value

sensorMax = sensorValue;

}

if (sensorValue < sensorMin) { //

If it is less than the previous min

value, it is the new lowest value

sensorMin = sensorValue;

}

}

}

You can then take your reading using a function

like the following code, which ...