Calibration - // minimum sensor value int sensorMax = 0; //...

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/* Calibration Demonstrates one technique for calibrating sensor input. The sensor readings during the first five seconds of the sketch execution define the minimum and maximum of expected values attached to the sensor pin. The sensor minimum and maximum initial values may seem backwards. Initially, you set the minimum high and listen for anything lower, saving it as the new minimum. Likewise, you set the maximum low and listen for anything higher as the new maximum. The circuit: * Analog sensor (potentiometer will do) attached to analog input 0 * LED attached from digital pin 9 to ground created 29 Oct 2008 By David A Mellis Modified 4 Sep 2010 By Tom Igoe http://arduino.cc/en/Tutorial/Calibration This example code is in the public domain. */ // These constants won't change: const int sensorPin = A0; // pin that the sensor is attached to const int ledPin = 9; // pin that the LED is attached to c // variables: int sensorValue = 0; // the sensor value int sensorMin = 1023;
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Unformatted text preview: // minimum sensor value int sensorMax = 0; // maximum sensor value i void setup() { // turn on LED to signal the start of the calibration period: pinMode(13, OUTPUT); digitalWrite(13, HIGH); // calibrate during the first five seconds while (millis() < 5000) { sensorValue = analogRead(sensorPin); // record the maximum sensor value if (sensorValue > sensorMax) { sensorMax = sensorValue; } // record the minimum sensor value if (sensorValue < sensorMin) { sensorMin = sensorValue; } } // signal the end of the calibration period digitalWrite(13, LOW); } void loop() { // read the sensor: sensorValue = analogRead(sensorPin); // apply the calibration to the sensor reading sensorValue = map(sensorValue, sensorMin, sensorMax, 0, 255); // in case the sensor value is outside the range seen during calibration sensorValue = constrain(sensorValue, 0, 255); // fade the LED using the calibrated value: analogWrite(ledPin, sensorValue); }...
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Calibration - // minimum sensor value int sensorMax = 0; //...

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