'use strict';

window.addEventListener('load', function (){

// WebGPIO LED Blink
  navigator.requestGPIOAccess().then(
    function(gpioAccess) {
        console.log("GPIO ready!");
        return gpioAccess;
    }).then(gpio=>{
      var port = gpio.ports.get(256);
      var v = 0;
      return port.export("out").then(()=>{
        setInterval(function(){
          v = v ? 0 : 1;
          port.write(v);
        },5000);
      });
  }).catch(error=>{
    console.log("Failed to get GPIO access catch: " + error.message);
  });
}, false);

'use strict';

window.addEventListener('load', function (){

// WebGPIO LED Blink
  navigator.requestGPIOAccess().then(
    function(gpioAccess) {
        console.log("GPIO ready!");
        return gpioAccess;
    }).then(gpio=>{
      var port = gpio.ports.get(198);
      var v = 0;
      return port.export("out").then(()=>{
        setInterval(function(){
          v = v ? 0 : 1;
          port.write(v);
        },1000);
      });
  }).catch(error=>{
    console.log("Failed to get GPIO access catch: " + error.message);
  });
}, false);

Change gpio port number and blink interval.
Change gpio port number and blink interval.
