pi-multifx-pedal/scripts/setup-bt-midi.sh

#!/usr/bin/env bash
# ── Pi Multi-FX Pedal — Bluetooth MIDI Setup ───────────────────────
# Enables Bluetooth MIDI (BLE-MIDI) so wireless controllers,
# expression pedals, and phone apps can send MIDI to the pedal.
#
# Usage:
#   sudo bash scripts/setup-bt-midi.sh              # Interactive setup
#   sudo bash scripts/setup-bt-midi.sh --disable    # Remove BT MIDI service
#   sudo bash scripts/setup-bt-midi.sh --pair-only  # Just make it discoverable
#
# Requirements:
#   Built-in RPi Bluetooth, or USB BT dongle
#   bluez, bluez-utils (installed by this script)
# ────────────────────────────────────────────────────────────────────

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PROJECT_DIR="$(dirname "$SCRIPT_DIR")"

DISABLE=false
PAIR_ONLY=false

while [[ $# -gt 0 ]]; do
    case "$1" in
        --disable)    DISABLE=true; shift ;;
        --pair-only)  PAIR_ONLY=true; shift ;;
        --help|-h)    echo "Usage: $0 [--disable] [--pair-only]"; exit 0 ;;
        *)            echo "Unknown: $1"; exit 1 ;;
    esac
done

RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; CYAN='\033[0;36m'; NC='\033[0m'
info()  { echo -e "${CYAN}[INFO]${NC} $1"; }
ok()    { echo -e "${GREEN}[OK]${NC}   $1"; }
warn()  { echo -e "${YELLOW}[WARN]${NC} $1"; }
fail()  { echo -e "${RED}[FAIL]${NC} $1"; }

if [ "$DISABLE" = true ]; then
    echo ""
    info "Disabling Bluetooth MIDI..."

    sudo systemctl stop bluetooth-midi 2>/dev/null || true
    sudo systemctl disable bluetooth-midi 2>/dev/null || true
    sudo rm -f /etc/systemd/system/bluetooth-midi.service

    # Restart bluetooth in standard mode
    sudo systemctl restart bluetooth
    ok "Bluetooth MIDI disabled"
    exit 0
fi

echo ""
echo "╔═══════════════════════════════════════════════╗"
echo "║   Pi Multi-FX Pedal — Bluetooth MIDI Setup    ║"
echo "╚═══════════════════════════════════════════════╝"
echo ""

# 1. Install bluez
info "Installing Bluetooth packages..."
sudo apt-get install -y -qq bluez bluez-utils bluez-tools 2>/dev/null || true
ok "Bluetooth packages installed"

# 2. Ensure BT hardware is on
info "Enabling Bluetooth hardware..."
sudo raspi-gpio set 28 a0 2>/dev/null || true  # Enable BT on RPi
sudo hciconfig hci0 up 2>/dev/null || true
ok "Bluetooth hardware enabled"

# 3. Enable BT MIDI plugin in bluez
info "Configuring BlueZ for MIDI..."
BLUEZ_CONF="/etc/bluetooth/main.conf"
if [ -f "$BLUEZ_CONF" ]; then
    sudo sed -i 's/^#Class *= *0x000100/Class = 0x002300/' "$BLUEZ_CONF" 2>/dev/null || true
    sudo sed -i 's/^#DiscoverableTimeout *= *0/DiscoverableTimeout = 0/' "$BLUEZ_CONF" 2>/dev/null || true
    sudo sed -i 's/^#PairableTimeout *= *0/PairableTimeout = 0/' "$BLUEZ_CONF" 2>/dev/null || true
fi
ok "BlueZ configured for discoverable + pairable MIDI"

# 4. Make device discoverable
info "Making pedal discoverable as 'Pi-Pedal-MIDI'..."
cat <<EOF | sudo bluetoothctl
power on
discoverable on
pairable on
scan on
name Pi-Pedal-MIDI
EOF
sleep 1
ok "Pedal is discoverable as 'Pi-Pedal-MIDI'"

if [ "$PAIR_ONLY" = true ]; then
    echo ""
    echo "╔═══════════════════════════════════════════════╗"
    echo "║   Pairing Mode Active                         ║"
    echo "║                                              ║"
    echo "║   Scan for 'Pi-Pedal-MIDI' from your device  ║"
    echo "║   and pair. The pedal stays discoverable     ║"
    echo "║   for 5 minutes, then returns to normal.     ║"
    echo "╚═══════════════════════════════════════════════╝"
    # Keep discoverable for 5 min then settle
    (sleep 300 && echo "settle" | sudo bluetoothctl) &
    exit 0
fi

# 5. Create systemd service for BT MIDI
info "Creating bluetooth-midi systemd service..."

cat <<'SERVICE' | sudo tee /etc/systemd/system/bluetooth-midi.service > /dev/null
[Unit]
Description=Pi Multi-FX Pedal — Bluetooth MIDI Service
After=bluetooth.service
Requires=bluetooth.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/bin/bluetoothctl discoverable on
ExecStartPost=/usr/bin/bluetoothctl pairable on
ExecStartPost=/usr/bin/bluetoothctl name Pi-Pedal-MIDI
ExecStop=/usr/bin/bluetoothctl discoverable off
Restart=no

[Install]
WantedBy=multi-user.target
SERVICE

# 6. Register MIDI over BLE with ALSA (a2dp-midi bridge)
# On modern BlueZ (5.50+), BLE-MIDI shows up as a sequencer port automatically
# Verify with: aconnect -o -l | grep -i midi

sudo systemctl daemon-reload
sudo systemctl enable bluetooth-midi
sudo systemctl start bluetooth-midi

# 7. Also start the pedal's MIDI handler to accept BT MIDI
# The MIDI handler already listens on ALSA sequencer ports
info "MIDI handler will auto-detect BT MIDI sequencer ports on next pedal start"

ok "Bluetooth MIDI service started"

echo ""
echo "╔═══════════════════════════════════════════════╗"
echo "║   Bluetooth MIDI Setup Complete 🎸            ║"
echo "╚═══════════════════════════════════════════════╝"
echo ""
echo "  📡 Name: Pi-Pedal-MIDI"
echo "  🎛 Connect from: Phone, tablet, wireless footswitch"
echo ""
echo "  From your phone:"
echo "    1. Enable Bluetooth"
echo "    2. Scan for 'Pi-Pedal-MIDI'"
echo "    3. Pair"
echo "    4. Open any MIDI controller app"
echo ""
echo "  To disable later:"
echo "    sudo bash $0 --disable"
echo ""