Troubleshooting MIDI Connections

When experiencing connection issues with MIDIHub, follow these troubleshooting steps to quickly identify and resolve problems.

Quick Fixes

Try these steps first - they resolve most issues:

1. Fully restart all participating devices - This clears temporary glitches and resets connections
2. Check permissions - Grant all requested permissions including location, Bluetooth, and nearby devices
3. Disable battery optimization - Android’s power saving can interrupt MIDI connections
4. Check the service log and port logs - The port overview provides detailed connection information

Understanding the Port Overview

The port overview log shows real-time connection status and MIDI activity:

• Blue status light: Port is idle and ready
• Green status light: Successfully connected
• Red status light: Connection issue or device not connected

Access the log by tapping the info button next to any port to see detailed MIDI messages and system events.

Connection-Specific Issues

USB MIDI Not Working

• Set Android USB preferences to MIDI mode (Settings → Connected devices → USB)
• Try a different USB cable - some cables are charge-only
• Restart both devices after connecting

Bluetooth LE Issues

• Location permission is required - Bluetooth technology can determine location, so Android requires this permission
• Enable location services in addition to granting permission for some devices
• Ensure the device is in pairing mode
• Check if the device is already connected to another app

RTP-MIDI Network Problems

• Requires WiFi or Ethernet connection without VPN
• Ensure both devices are on the same network
• Check that port 5004 isn’t blocked by firewall
• Disable mobile data to force WiFi usage

Virtual Ports Not Appearing

• The other app must also support virtual MIDI ports
• Some apps require you to enable virtual port support in their settings
• Restart both apps if ports don’t appear immediately

Using the Logs

The service log and port logs provide valuable diagnostic information:

1. Service Log: Shows system-level events like permission issues or service crashes
2. Port Logs: Display MIDI messages and connection events for each port
3. Message Details: Each log entry shows timestamp, message type, and data bytes

Advanced Troubleshooting

Permission Details

Even though MIDIHub doesn’t track you, Bluetooth technology itself could potentially be used to determine your location. This is why location permission is required to scan for nearby Bluetooth devices. In some cases, enabling location services—in addition to granting location permission—might even be necessary to discover your specific device.

Background Operation

If the app runs in the background, you’ll receive notifications for important events like connection losses. This helps you quickly identify when issues occur during live performances.

Finding Help

If these steps don’t resolve your issue:

1. Check the online manual for detailed documentation
2. Email the developer directly from the app’s help section
3. Include log information when reporting issues for faster resolution

The help button (?) throughout the app provides context-specific information for each feature.

Prevention Tips

• Save presets after successful connections to quickly restore working configurations
• Test connections before live performances
• Keep the app updated for the latest bug fixes and device compatibility
• Monitor the port overview during setup to catch issues early