Playing around with an BLE LED bulb and web-bluetooth

bulb.js

const serviceId = 0xffe5;
const characteristicId = 0xffe9;

const btn = document.getElementById('btn');
const form = document.forms[0];

let bulb;
document.getElementById('random').addEventListener('click',()=> {
	setInterval(()=> {
		bulb.writeValue(getColorValue(Math.ceil(Math.random()*255), Math.ceil(Math.random()*255), Math.ceil(Math.random()*255)));
	}, 500);
})

function getColorValue(red, green, blue) {
	if(red === "255" && green === "255" && blue === "255") {
		const strength = 255;
		return new Uint8Array([0x56, 00, 00, 00, strength, 0x0f, 0xaa]);
	}
	return new Uint8Array([0x56, red, green, blue, 0x00, 0xf0, 0xaa]);
}

form.addEventListener('submit', event=> {
	event.preventDefault();

	const red = event.target.red.value;
	const green = event.target.green.value;
	const blue = event.target.blue.value;

	const value = getColorValue(red, green, blue);

	bulb.writeValue(value);
	
	return false;
});

btn.addEventListener('click', ()=> {
	navigator.bluetooth.requestDevice({ 
			filters: [{ 
				services: [serviceId],
				name:'LEDBLE-A6E811E9' 
			}] 
		})
		.then(device => { 
			device.gatt.connect()
				.then(server => server.getPrimaryService(serviceId))
				.then(service => service.getCharacteristic(characteristicId))
				.then(characteristic => {
					bulb = characteristic;
					form.style.display = 'block';
					btn.style.display = 'none';
				})
		})
		.catch(error => { 
			console.log(error); 
		});

});