hand.js

const UART_SERVICE_UUID = "6e400001-b5a3-f393-e0a9-e50e24dcca9e";
const UART_TX_UUID = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"; // TX characteristic for micro:bit v2

class Hand {
	constructor() {
		this.bluetoothDevice = undefined;
		this.uartService = undefined;
	}

	async connect() {
		try {
			this.bluetoothDevice = await navigator.bluetooth.requestDevice({
				filters: [{ namePrefix: "BBC" }], // Filter for devices with names starting with "BBC"
				optionalServices: [UART_SERVICE_UUID],
			});

			const server = await this.bluetoothDevice.gatt.connect();
			const service = await server.getPrimaryService(UART_SERVICE_UUID);
			this.uartService = await service.getCharacteristic(UART_TX_UUID);

			console.log("Connected to hand!");
		} catch (error) {
			console.error("Failed to connect to hand:", error);
			alert("Failed to connect to hand. Please try again.");
		}
	}

	async sendCommand(actionNumber) {
		if (this.uartService === undefined) {
			console.error("Not connected to micro:bit");
			alert("Please connect to Hand first!");
			return;
		}
		try {
			// Convert action number to hex and pad to two characters
			const hexAction = actionNumber.toString(16).toUpperCase().padStart(2, "0");
			const command = `CMD|0F|${hexAction}|$`;
			const encoder = new TextEncoder();
			await this.uartService.writeValue(encoder.encode(command));
			console.log(`Command sent: ${command}`);
		} catch (error) {
			console.error("Failed to send command:", error);
			alert("Failed to send command to Yorick.");
		}
	}
}