[Reference] attachInterrupt() example and documentation corrections #4723
Description
On the reference page https://www.arduino.cc/en/Reference/AttachInterrupt the example attaches the interrupt to pin 13 but that won't work for common Arduino boards such as Uno and Mega. Also I think it's better to use different pins for the interrupt and the output. I would suggest changing the interrupt pin to 2 or 3 as this will work on any of the listed boards except MKR1000 Rev.1. The updated example would look something like:
const byte ledPin = 13;
const byte interruptPin = 2;
volatile byte state = LOW;
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(interruptPin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(interruptPin), blink, CHANGE);
}
void loop() {
digitalWrite(ledPin, state);
}
void blink() {
state = !state;
}
Originally reported at http://forum.arduino.cc/index.php?topic=385081.0 and https://forum.arduino.cc/index.php?topic=358930.0
A couple other typos in the attachInterrupt() reference page:
Normally you should use digitalPinToInterrupt(pin), rather than place interrupt an number directly into your sketch.
should be changed to:
Normally you should use digitalPinToInterrupt(pin), rather than place an interrupt number directly into your sketch.
and:
Four contstants are predefined as valid values:
should be changed to
Four constants are predefined as valid values: