node-zwave-js/docs/examples/basic-on-off.md

💡 Blink a light with Basic CC

NOTE: The following example builds on the Quick Start guide. Make sure you have followed the steps there before continuing.

?> Most functionality of Command Classes is available through the commandClasses API of endpoints and nodes. In this example, we'll use the Basic CC API to make a light blink.

To communicate with a node, we first need to get a reference to it. This is done by calling driver.controller.nodes.get() with the node ID. driver is the driver instance we created in the getting started guide.

// inside `main()`:
const node = driver.controller.nodes.get(2);

This assumes that your node has ID 2. Replace it with the correct ID if necessary. If there is no node with ID 2, the node variable will be undefined. Make sure to check for this before proceeding. As an alternative you can use the getOrThrow() method, which will throw an error instead of returning undefined.

// inside `main()`:
const node = driver.controller.nodes.getOrThrow(2);

NOTE: If type-checking is enabled, this avoids having to check for undefined to satisfy the type checker if you know the node exists.

We now have access to Basic CC functionality through the node.commandClasses.Basic object. To toggle the light on and off, we can use the set() method. This method takes a value between 0 and 99, or 255, according to the Z-Wave specifications. The following code turns the light on to full brightness:

await node.commandClasses.Basic.set(99);

To be able to wait for a certain amount of time, we'll use the timers/promises API from Node.js. Add the following import to the top of your script:

import { setTimeout } from "node:timers/promises";

Now we can a loop and toggle the light 10x every 500 ms:

for (let i = 0; i < 10; i++) {
	await node.commandClasses.Basic.set(i % 2 === 0 ? 255 : 0);
	await setTimeout(500);
}

---

Full example:

import { setTimeout } from "node:timers/promises";
import { Driver } from "zwave-js";

// ...driver initialization, see Quick Start guide

async function main() {
	const node = driver.controller.nodes.getOrThrow(2);

	for (let i = 0; i < 10; i++) {
		await node.commandClasses.Basic.set(i % 2 === 0 ? 255 : 0);
		await setTimeout(500);
	}
}