digitalRead(pin, [callback])

Read the status of a digital I/O pin.

Arguments

• pin: the BeagleBone pin identifier
• callback: called upon completion

Return value

• HIGH if pin is HIGH
• LOW if pin is LOW

callback(x)

• x.value: return value
• x.err: error status message

Example run restore

var b = require('bonescript');
b.pinMode('P8_19', b.INPUT);
b.digitalRead('P8_19', printStatus);
function printStatus(x) {
    console.log('x.value = ' + x.value);
    console.log('x.err = ' + x.err);
}

Build and execute instructions

• Apply 0V to P8_19 and run the example code.
• Apply 3.3V to P8_19 and run the example code again.
• Alter the code to look at inputs on other pins.

See also

Topics

• BeagleBone expansion headers
• Digital I/O

Related functions

• require
• pinMode
• digitalWrite
• attachInterrupt

Examples

• Bacon Cape