fix: work around corrupted high nibble in ACK after soft-reset on 7.19.x

packages/serial/src/ZWaveSerialPortBase.ts

@@ -115,6 +115,11 @@ export class ZWaveSerialPortBase extends PassThrough {
 	// Allow switching between modes
 	public mode: ZWaveSerialMode | undefined;
 
+	// Allow ignoring the high nibble of an ACK once to work around an issue in the 700 series firmware
+	public ignoreAckHighNibbleOnce(): void {
+		this.parser.ignoreAckHighNibble = true;
+	}
+
 	// Allow strongly-typed async iteration
 	declare public [Symbol.asyncIterator]: () => AsyncIterableIterator<
 		ZWaveSerialChunk

packages/serial/src/parsers/SerialAPIParser.ts

@@ -1,3 +1,4 @@
+import { num2hex } from "@zwave-js/shared";
 import { Transform, type TransformCallback } from "node:stream";
 import type { SerialLogger } from "../Logger";
 import { MessageHeaders } from "../MessageHeaders";
@@ -26,6 +27,9 @@ export class SerialAPIParser extends Transform {
 
 	private receiveBuffer = Buffer.allocUnsafe(0);
 
+	// Allow ignoring the high nibble of an ACK once to work around an issue in the 700 series firmware
+	public ignoreAckHighNibble: boolean = false;
+
 	_transform(
 		chunk: any,
 		encoding: string,
@@ -58,6 +62,24 @@ export class SerialAPIParser extends Transform {
 						// INS12350: A host or a Z-Wave chip waiting for new traffic MUST ignore all other
 						// byte values than 0x06 (ACK), 0x15 (NAK), 0x18 (CAN) or 0x01 (Data frame).
 
+						// Work around a bug in the 700 series firmware that causes the high nibble of an ACK
+						// to be corrupted after a soft reset
+						if (
+							this.ignoreAckHighNibble
+							&& (this.receiveBuffer[0] & 0x0f)
+								=== MessageHeaders.ACK
+						) {
+							this.logger?.message(
+								`received corrupted ACK: ${
+									num2hex(this.receiveBuffer[0])
+								}`,
+							);
+							this.logger?.ACK("inbound");
+							this.push(MessageHeaders.ACK);
+							this.ignoreAckHighNibble = false;
+							break;
+						}
+
 						// Scan ahead until the next valid byte and log the invalid bytes
 						while (skip < this.receiveBuffer.length) {
 							const byte = this.receiveBuffer[skip];

packages/testing/src/MockController.ts

@@ -10,6 +10,7 @@ import type { MockPortBinding } from "@zwave-js/serial/mock";
 import { AsyncQueue } from "@zwave-js/shared";
 import { TimedExpectation, createWrappingCounter } from "@zwave-js/shared/safe";
 import { wait } from "alcalzone-shared/async";
+import { randomInt } from "node:crypto";
 import {
 	type MockControllerCapabilities,
 	getDefaultMockControllerCapabilities,
@@ -151,6 +152,8 @@ export class MockController {
 	public autoAckHostMessages: boolean = true;
 	/** Controls whether the controller automatically ACKs node frames before handling them */
 	public autoAckNodeFrames: boolean = true;
+	/** Allows reproducing issues with the 7.19.x firmware where the high nibble of the ACK after soft-reset is corrupted */
+	public corruptACK: boolean = false;
 
 	/** Gets called when parsed/chunked data is received from the serial port */
 	private async serialOnData(
@@ -342,7 +345,14 @@ export class MockController {
 	 * Sends an ACK frame to the host
 	 */
 	public ackHostMessage(): void {
-		this.sendHeaderToHost(MessageHeaders.ACK);
+		if (this.corruptACK) {
+			const highNibble = randomInt(1, 0xf) << 4;
+			this.serial.emitData(
+				Buffer.from([highNibble | MessageHeaders.ACK]),
+			);
+		} else {
+			this.sendHeaderToHost(MessageHeaders.ACK);
+		}
 	}
 
 	/** Gets called when a {@link MockZWaveFrame} is received from a {@link MockNode} */

packages/zwave-js/src/lib/driver/Driver.ts

@@ -2519,6 +2519,15 @@ export class Driver extends TypedEventEmitter<DriverEventCallbacks>
 			await this.sendMessage(new SoftResetRequest(this), {
 				supportCheck: false,
 				pauseSendThread: true,
+				// Work around an issue in the 700 series firmware where the ACK after a soft-reset has a random high nibble
+				onProgress: (progress) => {
+					// This was broken in 7.19, not fixed so far
+					if (this.controller.sdkVersionGte("7.19.0")) {
+						if (progress.state === TransactionState.Active) {
+							this.serial?.ignoreAckHighNibbleOnce();
+						}
+					}
+				},
 			});
 		} catch (e) {
 			this.controllerLog.print(

packages/zwave-js/src/lib/test/compat/corruptACKAfterSoftReset.test.ts

@@ -0,0 +1,22 @@
+import { integrationTest } from "../integrationTestSuite";
+
+// Repro for https://github.com/zwave-js/node-zwave-js/issues/6399
+
+integrationTest(
+	"Accept corrupted ACKs with a random high nibble after Soft Reset",
+	{
+		debug: true,
+
+		controllerCapabilities: {
+			libraryVersion: "Z-Wave 7.19.1",
+		},
+
+		testBody: async (t, driver, node, mockController, mockNode) => {
+			mockController.clearReceivedHostMessages();
+
+			mockController.corruptACK = true;
+			await t.notThrowsAsync(driver.softReset());
+			mockController.corruptACK = false;
+		},
+	},
+);