Venue Commander — Audio Board

Overview

The Audio Board is a small second board that sits next to the touchscreen and handles all the audio: pairing with phones, streaming music over Bluetooth, transport controls, volume sync, optional line-in mixing, and output to a line-level / headphone / speaker connection. It appears in the web UI as a built-in audio device — you place audio widgets the same way you place anything else.

What You Get

Bluetooth audio receiver — stream from any phone, tablet, or laptop
Volume sync + transport — play / pause / next / previous from either side, with the touchscreen and phone always agreeing on the level
Now-playing info — title, artist, album from the connected device
Show Mode — lock to one Bluetooth device for a show, refusing all others (default 5 h, max 24 h)
Paired-device management — allow/deny, friendly names, temporary kick, unpair
Optional line-in mixing on supported boards — a line-level source mixed with the Bluetooth stream
Bluetooth name matches the venue — the “speaker” your phone sees is whatever you've called the touchscreen

📷 Photo: Audio Board mounted alongside the touchscreen A wide shot showing the touchscreen panel and the audio-board PCB connected by a short cable, with audio cables running off to an amplifier or active speaker.

Hardware

Audio Board

Audio codec	Two options: a WM8960 board (line in + out, headphone, speaker), or a PCM5122 board (line out only, no line in)
Outputs	Line level, headphone, and speaker (depending on which codec you fit)
Inputs	Line in (WM8960 only)
Networking	None — the audio board doesn't connect to WiFi. The touchscreen handles all networking and relays control commands over a short wired link.

Splitting audio onto its own board is what keeps the Bluetooth stream stable: WiFi traffic on the touchscreen doesn't compete with the Bluetooth radio on the audio board. Streaming continues cleanly while you're scanning networks, browsing the web UI, or applying updates.

Wiring

The audio board connects to the touchscreen with four wires (two signal wires, ground, and optionally 5 V power). Exact pin numbers vary by touchscreen board — refer to the hardware notes that came with your specific touchscreen.

Audio output goes from the audio board to your amplifier or active speakers via 3.5 mm jack or screw-terminal speaker output, depending on which codec board you have.

Loading Firmware (first time)

The very first time, the audio board needs its firmware loaded over USB. After that, every later update can be done wirelessly from the touchscreen's web UI — see Settings → Update.

Setting up an audio board from scratch is a build-it-yourself process that needs the source repository and developer tools (the same tools you'd use to install or update Venue Commander itself on a touchscreen). If you have a pre-flashed audio board, you can skip this step entirely — just connect it to the touchscreen and you're done.

Once the audio board is connected and responding, the touchscreen's Audio Board Firmware upload card appears on the Update tab. From that point on, you can upgrade the audio board without unplugging anything.

First Bluetooth Pairing

The audio board advertises itself as a Bluetooth speaker using whatever you've set as the touchscreen's Display Name. There's no PIN to enter — pairing is “just works”.

Make sure the audio board is powered, the touchscreen is on, and Show Mode is off in the Audio tab.
On your phone, open Bluetooth settings and scan. Look for a device named whatever you've called the touchscreen (e.g. “Studio A”).
Tap to pair. The phone connects, the Audio tab in the web UI updates within about a second, and any “Device Name” info widget on the touchscreen shows the phone's friendly name.
Play music. Volume control on the phone now drives the audio board's output, and a BT Volume fader (if you've placed one on a page) tracks the phone's level in both directions.

If you rename the touchscreen later, paired phones still show the old name in their saved-device list until you unpair and re-pair from the phone side. A fresh scan from any other phone shows the new name immediately. This is just how Bluetooth works.

Widgets & the Audio Tab

📷 Screenshot: Audio tab Web UI Audio tab — Status row at the top (connected device name, playing/paused, signal strength), Now Playing card (title/artist/album), volume sliders (BT volume + line-in level), Show Mode panel with countdown, paired-devices list with allow/deny, friendly-name input, kick / kick 10 min / unpair / connect buttons.

Once the audio board is connected, the web UI gains an Audio tab. Everything the audio board can do is here. The same controls are also available as widgets on the touchscreen — see the audio presets in Layout → Widgets.

What's on the Audio tab

Status	Bluetooth connection state, connected device name, what's currently happening (playing / paused / stopped), and signal strength. Live updates — you never need to refresh.
Now Playing	Title, artist, album from the connected device. Empty when nothing is playing.
Playback	Previous / Play-Pause / Next buttons. Only enabled when a Bluetooth device is connected.
BT Volume	0–100 slider, syncs in both directions with the phone.
Aux Level	0–100 line-in mix level (only on audio boards with line-in support). Mixed with the Bluetooth stream before being sent to the speaker output.
Output Level	Master output level. Reduce if the line out is too loud or clips into your amplifier.
Show Mode	Toggle + duration input. While active, all other Bluetooth devices are refused. Countdown shows time remaining. Forced off when no device is connected.
Devices	One row per paired Bluetooth device: allow/deny checkbox, friendly-name input, Connect, Kick, Kick 10 min, Unpair. Plus an Unpair All button. Disabled while Show Mode is active.

The Audio tab updates live — volume changes from the phone, songs starting and stopping, devices connecting and disconnecting all appear within about a tenth of a second.

Show Mode

Show Mode locks the audio board to a single Bluetooth device for the duration of a show. While active:

Other phones can't see or connect to the audio board — it disappears from Bluetooth scans.
Even previously-paired phones that try to auto-reconnect are refused. The locked device is the only one allowed through.
Kick, temporary kick, unpair, unpair all, connect, and the allow/deny toggle are all disabled until Show Mode ends — in the web UI, on the touchscreen, and over the network. No-one can accidentally bump the show off the speaker.
Volume, play/pause/next/prev, and “Show Mode off” remain available.

To activate Show Mode, a Bluetooth device must already be connected — you can't reserve a future device. Duration is 1–1440 minutes (default 5 hours). It auto-expires; you can also cancel early by setting minutes to 0.

Show Mode resets if the audio board itself loses power. If it reboots mid-show, you'll have to re-activate it. (Restarting the touchscreen doesn't affect Show Mode — the audio board carries on regardless.)

Troubleshooting

The Audio tab doesn't appear

The touchscreen marks the audio board as disconnected after 15 seconds without a response. Things to check:

Cable: is it plugged in at both ends? Are the signal wires the right way round (the TX from one end goes to the RX of the other)? Is the ground wire connected?
Is the audio board powered? Does its status LED come on?
If you've recently updated only one side (touchscreen or audio board), check both have compatible firmware — an old audio board talking to a new touchscreen (or vice versa) may not understand each other.

Audio stutters or volume jumps around

The most common cause is a loose cable between the touchscreen and the audio board. Re-seat the connectors at both ends. If you're using temporary jumper wires for testing, switch to a soldered or crimped connection — jumper wires are unreliable for the data lines under load.

The phone shows the old device name after I renamed the touchscreen

Expected. Bluetooth phones cache the friendly name when they first pair. Unpair and re-pair on the phone to pick up the new name. Other phones scanning fresh will see the current name without needing any action.

Credits

Show mode, paired-device management, transport metadata, and the remote-control surface were originally developed for the standalone BT Esparagus project, running on Sonocotta's Esparagus HiFi MediaLink hardware. The audio-board firmware brings those features into a board that lives next to the touchscreen. Thanks to Sonocotta for the original hardware design.