Project ChordsPlay Raspberry Pi Test

Testing the Fender Mustang Micro Plus tools on a Raspberry Pi with Raspberry Pi OS 13 (trixie): maneline's Micro Plus programs (package maneline-mmp, built from my fork) and the BlueZ 5.88 they need. Part of ChordsPlay; not official, no support. Nothing here has run on a real Pi yet: that is what this test is for.

What you need

• A Raspberry Pi with Raspberry Pi OS 13. 64-bit (default on Pi 4 and 5, possible on Pi 3 and Zero 2 W) uses the repositories named Debian_13 below; 32-bit uses Raspbian_13.
• A Mustang Micro Plus, ideally on USB power, and something to play music to it over Bluetooth.

1. BlueZ 5.88

Raspberry Pi OS 13 ships BlueZ 5.82; the tools need 5.86 or newer for the LE bearer interface. This repository has Debian testing's 5.88 rebuilt for trixie, with Raspberry Pi OS's own audio patch (avdtp_set_priority). It replaces the system's Bluetooth stack.

R=https://download.opensuse.org/repositories/home:/joba1:/chordsplay
B=$R:/bluez/Debian_13          # 32-bit: $R:/bluez/Raspbian_13
curl -fsSL $B/Release.key | gpg --dearmor | sudo tee /etc/apt/keyrings/chordsplay-bluez.gpg >/dev/null
echo "deb [signed-by=/etc/apt/keyrings/chordsplay-bluez.gpg] $B/ /" | sudo tee /etc/apt/sources.list.d/chordsplay-bluez.list
sudo apt update && sudo apt upgrade && sudo reboot
bluetoothctl --version         # 5.88

2. BlueZ setup

Put Experimental = true into the [General] section of /etc/bluetooth/main.conf, then sudo systemctl restart bluetooth.

3. The tools

P=$R/Debian_13                 # 32-bit: $R/Raspbian_13
curl -fsSL $P/Release.key | gpg --dearmor | sudo tee /etc/apt/keyrings/chordsplay.gpg >/dev/null
echo "deb [signed-by=/etc/apt/keyrings/chordsplay.gpg] $P/ /" | sudo tee /etc/apt/sources.list.d/chordsplay.list
sudo apt update && sudo apt install maneline-mmp

Commands: mmp-web, mmp-ble, mmp-backup, mmp-restore, mmp-audition, mmp-check, mmp-level, mmp-bluez-setup. Documents: /usr/share/doc/maneline-mmp.

4. Pairing

Pair the amp for audio as usual, then with the amp on:

sudo mmp-bluez-setup AA:BB:CC:DD:EE:FF      # the amp's address, from: bluetoothctl devices

5. Test

First a backup of all presets (needs the amp to itself, so nothing else connected to it):

mmp-backup                                   # writes ~/.local/share/maneline-mmp/backups/micro-plus-<time>

Then the browser controls, which keep the one connection the amp allows:

mmp-web --port 8081                          # then open http://<pi>:8081 in a browser

• Play music from the Pi to the amp over Bluetooth and switch presets in the page: does the audio keep playing, any dropouts?
• With mmp-web still running, in a second terminal:

mmp-check ~/.local/share/maneline-mmp/backups/micro-plus-<time> --all

Please report

• Pi model, Raspberry Pi OS 32 or 64 bit.
• The output of bluetoothctl --version, of mmp-bluez-setup and of mmp-check … --all.
• Audio dropouts while switching: yes or no.
• Every step that needed something not written here.

Going back

sudo apt purge maneline-mmp
sudo rm /etc/apt/sources.list.d/chordsplay-bluez.list && sudo apt update
sudo apt install --allow-downgrades bluez/trixie