Cycle voltage on Raspberry Pi gpio header in node

RasPi-blinkToggle.js

var gpio = require('gpio');
var header4, header17, intervalTimer;

header4 = gpio.export(4);
header17 = gpio.export(17, {
        ready: function() {
                intervalTimer = setInterval(function() {
                        header4.set();
                        setTimeout(function() { header4.reset(); }, 500);
                }, 1000);
                header4.on('change', function(val) { header17.set(1-val); });
        }
});


// after 10 seconds, reset all the headers, unexport and quit program
setTimeout(function() {
        clearInterval(intervalTimer);
        header4.removeAllListeners('valueChange');
        header4.reset();
        header4.unexport();

        header17.reset();
        header17.unexport(function(){
                process.exit();
        });
}, 10000);