Don't send heartbeat if we've written something within the heartbeat interval....

Don't send heartbeat if we've written something within the heartbeat interval. (This didn't solve my problem anyway so might be best to just move heartbeat back to SerialDevice exclusively.)

src/lib/device.ts

@@ -35,7 +35,7 @@ export default abstract class Device extends js.global.EventEmitter {
 	private readyEvent: number;
 	private heartbeatInterval: number;
 	private heartbeatEvent: number;
-	private lastHeartbeat?: number;
+	private lastWrite: number;
 	private initTime: number;
 	private initTimeout: number;
 	private readonly timeoutMs: number = RESPONSE_TIMEOUT * 1000;
@@ -58,8 +58,9 @@ export default abstract class Device extends js.global.EventEmitter {
 		this.ackHandlers = {};
 		this.responseHandlers = {};
 		this.purgeEvent = js.setInterval(this.purgeHandlers, this.timeoutMs, this);
-		this.heartbeatInterval = heartbeatInterval;
+		this.heartbeatInterval = heartbeatInterval * 1000;
 		this.heartbeatEvent = -1;
+		this.lastWrite = Date.now();
 		this.initTime = Date.now();
 		this.initTimeout = CONNECT_TIMEOUT * 1000;
 	}
@@ -126,10 +127,7 @@ export default abstract class Device extends js.global.EventEmitter {
 		if (!this.ready && now - this.initTime > this.initTimeout) this.error(`initialization timeout (configCompleteId not received from device)`);
 		this.read();
 		this.purgeHandlers();
-		if (this.lastHeartbeat === undefined || now - this.lastHeartbeat >= this.heartbeatInterval) {
-			this.lastHeartbeat = now;
 		this.sendHeartbeat();
-		}
 		this._cycle();
 	}
 
@@ -187,7 +185,7 @@ export default abstract class Device extends js.global.EventEmitter {
 					if (this.readyEvent > -1) js.clearTimeout(this.readyEvent);
 					this.emit('ready');
 					// @ts-expect-error shut up
-					this.heartbeatEvent = js.setInterval(function () { this.sendHeartbeat(); }, 30000, this)
+					this.heartbeatEvent = js.setInterval(function () { this.sendHeartbeat(); }, this.heartbeatInterval, this)
 				}
 				break;
 			case 'metadata':
@@ -278,7 +276,9 @@ export default abstract class Device extends js.global.EventEmitter {
 		if (data.length > MAXLEN) this.error(`write: packet length ${data.length} exceeds maximum length ${MAXLEN}`);
 		const header = [START1, START2, (data.length>>8)&0xFF, data.length&0xFF];
 		const buffer = new Uint8Array([...header, ...data]);
-		return this.sendToDevice(buffer);
+		const res = this.sendToDevice(buffer);
+		if (res) this.lastWrite = Date.now();
+		return res;
 	}
 
 	/** Assembles a [MeshPacket](https://buf.build/meshtastic/protobufs/docs/main:meshtastic#meshtastic.MeshPacket) based on your parameters and writes it to the device. */
@@ -584,6 +584,7 @@ export default abstract class Device extends js.global.EventEmitter {
 
 	/** You probably don't need to call this directly. It's only really needed for SerialDevice, and is handled there for you even in synchronous scripts. */
 	sendHeartbeat(): void {
+		if (Date.now() - this.lastWrite < this.heartbeatInterval) return;
 		const toRadio: protobuf.Mesh.ToRadio = new protobuf.Mesh.ToRadio({
 			payloadVariant: {
 				case: 'heartbeat',