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Topic: Plus or minus X (Read 5853 times) previous topic - next topic


Jun 12, 2011, 10:03 pm Last Edit: Jun 12, 2011, 10:06 pm by AndyJarosz Reason: 1
Is there any way to have the Arduino recognize when it is within, say plus or minus 10 of a number? For example, if a rotary encoder is within X either way of a certain number, it lights an LED?


This should light up the pin 13 LED if encoderVal and otherVal happen to be 10 or less away from each other:
Code: [Select]
void setup() {               
  pinMode(13, OUTPUT);   
  int encoderVal = random(-20, 20);
  int otherVal = random(-20, 20);
  if(abs(encoderVal - otherVal) <= 10) {
    digitalWrite(13, HIGH);
  } else {
    digitalWrite(13, LOW);

void loop() {}



Also untested but shorter:
Code: [Select]

    digitalWrite(13, abs(encoderVal - otherVal) <= 10);
Check out my experiments http://blog.blinkenlight.net


Brilliant, thanks everyone!

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