Using https://github.com/nebrius/raspi-gpio on a Raspberry Pi to control digital pin states

switch-raspi

console.log('Hello Pi')

var raspi = require('raspi')
var gpio = require('raspi-gpio')

raspi.init(function() {
  console.log('Board-ready')

  var input = new gpio.DigitalInput(2)
  var output = new gpio.DigitalOutput(0)

 setInterval(function() {
   output.write(input.read())
 }, 1)
})

Reliably getting 250 us to 1 ms latencies using setInterval