Separate ESP32-U4WDH processor

Companion Firmware Installer

This installer is only for the second, classic ESP32 inside the Waveshare ESP32-S3-Knob-Touch-LCD-1.8. It never installs the main RoonPilot display firmware.

Optional. RoonPilot works fully without this firmware. Install it only if you want the unused companion processor placed into a defined low-power state.

What it does

One small firmware, three deliberate actions

Mutes the unused DAC

Keeps the PCM5100A muted through its XSMT control while RoonPilot is used as a controller.

Releases shared signals

Leaves audio, encoder and serial lines as inactive inputs instead of driving them.

Enters deep sleep

Puts the ESP32-U4WDH into indefinite deep sleep without a wake source.

Step 1 · USB data cable

Start directly in the Web Installer

Connect RoonPilot and continue on this page. No preliminary check in Device Manager or macOS System Information is required. The browser opens its device chooser only after you select Install Companion firmware:

Windows

Select this in the device chooser:

✓ USB serial (COM…)

Do not select: USB JTAG/serial debug unit

Detailed Windows instructions →

macOS

Select this in the device chooser:

✓ USB serial (cu.usbserial… or cu.wchusbserial…)

Do not select: USB JTAG/serial debug unit

Detailed macOS instructions →

If the open chooser shows USB JTAG/serial debug unit, unplug USB, turn the USB-C plug at the RoonPilot device by 180 degrees and reconnect it. The Web Installer detects the Companion side immediately and shows USB serial.

Optional information

Original-firmware backup

Most users can skip this. Create a complete backup now only if you may later want to restore the exact manufacturer-delivered state. The separate technical procedure needs esptool because a browser cannot save the existing flash.

Backup with Windows Backup with macOS

Step 2 · Chrome or Edge on a desktop computer

Install Companion Sleep

The manifest on this page contains a build for the classic ESP32 only. If the ESP32-S3 side is selected, the installer has no compatible build and must not write it.

In the device chooser that opens next, I will select USB serial for the classic Companion ESP32 and understand that this installation replaces its firmware. I have read and accept the RoonPilot Personal-Use Binary License 1.0.

Use a current desktop Chrome or Edge browser with Web Serial. Open this HTTPS page before connecting the USB device.

Loading firmware information…

Step 3

Return the cable to RoonPilot

1. Disconnect and turn

After verification finishes, unplug USB, turn the USB-C plug at the device by 180 degrees and reconnect it.

2. Wait for RoonPilot to start

RoonPilot now starts again from the main processor. There is no need to open Device Manager or System Information.

Why a separate installer?

Two processors, two guarded targets

The main installer accepts only ESP32-S3 hardware. This Companion installer accepts only classic ESP32 hardware. Keeping the manifests separate lets the installer reject the wrong processor family while keeping both procedures simple.