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MIDI & Devices

Android: USB (OTG) Connection Guide

Connect your USB MIDI keyboard to your Android phone or tablet. This guide covers OTG adapters, required settings for different manufacturers, and common troubleshooting steps.

The Short Version

You need a USB OTG adapter (~$10). Connect: Keyboard → USB cable → OTG adapter → Phone.
OnePlus/Xiaomi/Oppo users: Enable USB OTG in Settings first.

On This Page

1. What is USB OTG?

USB OTG (On-The-Go) lets your phone act as a USB "host" - the same role your computer plays when you plug in a keyboard or mouse. Without OTG, your phone can only be a "device" (like when you charge it from a computer).

Why is this needed? MIDI keyboards are USB "devices" that expect to connect to a "host." An OTG adapter tells your phone to switch into host mode so it can communicate with the keyboard.

Most Android phones made after 2015 support USB OTG. Crescendo will automatically detect your keyboard once it's properly connected.

2. What You Need

1

Android 6.0 or later

Android's MIDI API was introduced in Android 6.0 (Marshmallow). Most phones from 2016 onwards meet this requirement.

Check your version: Settings → About Phone → Android Version

2

USB OTG Adapter

A small adapter that converts your phone's USB-C port to a USB-A port (the type your keyboard cable plugs into).

USB-C to USB-A OTG Adapter

Recommended

Works with most modern Android phones

~$10

What to look for:

  • Must say "OTG" in the product name
  • USB-C male to USB-A female
  • From a reputable brand (Anker, UGREEN, etc.)

Charging-only adapters won't work

Not all USB-C adapters support OTG. Cheap "charging" adapters only transfer power, not data. Make sure "OTG" is clearly stated in the product description.

3

USB Cable (usually included with keyboard)

Most MIDI keyboards come with a USB-A to USB-B cable. The USB-B end (square-ish) plugs into your keyboard.

Connection chain:

MIDI Keyboard → USB-B → USB Cable → USB-A → OTG Adapter → USB-C → Android Phone

3. Phone-Specific Settings

Some Android manufacturers disable USB OTG by default or require additional settings. Find your phone brand below:

Phone Brand OTG Status Action Required
Google Pixel Enabled by default None - just plug in
Samsung Galaxy Enabled by default None - just plug in
OnePlus Manual enable Settings → Additional Settings → OTG
Xiaomi / MIUI Manual enable See detailed steps below
Oppo / Realme Manual enable Settings → Additional Settings → OTG Connection
Motorola Enabled by default None - just plug in

OnePlus, Xiaomi, Oppo: OTG Auto-Disables!

Critical

These phones automatically disable OTG after 10 minutes of inactivity to save battery. If your keyboard suddenly stops working mid-practice, you'll need to re-enable OTG in Settings.

Workaround: Play notes or touch the screen periodically to prevent the timeout.

Xiaomi / MIUI: Detailed Setup Steps

Step 1: Enable Developer Options

  1. Go to Settings → About Phone
  2. Find MIUI Version
  3. Tap it 7 times until you see "Developer mode has been enabled"

Step 2: Set USB Configuration to MIDI

  1. Go to Settings → Additional Settings → Developer Options
  2. Scroll down to find USB Configuration (or "Default USB configuration")
  3. Select MIDI

Step 3: Enable OTG

  1. Go to Settings → Additional Settings
  2. Find OTG Connection and toggle it ON

Note: Menu names may vary slightly depending on your MIUI version. If you can't find an option, use the search bar in Settings.

4. Step-by-Step Connection

1

Enable OTG (if required)

If you have a OnePlus, Xiaomi, or Oppo phone, enable USB OTG in your Settings first. See the table above for the exact location.

2

Turn on your keyboard

Power on your MIDI keyboard before connecting it. This helps Android detect it properly.

3

Connect the cable to your keyboard

Plug the USB-B end (square-ish connector) into your keyboard's "USB" or "To Host" port.

Tip: If your keyboard has multiple USB ports, use "To Host" or "USB to Computer" - not "To Device."

4

Connect the OTG adapter

Plug the USB-A end of the cable into your OTG adapter, then plug the adapter into your phone.

5

Open Crescendo and select your keyboard

Crescendo may auto-launch when you plug in the keyboard. If not:

  1. Open Crescendo
  2. Tap the MIDI button (top right) or go to Settings
  3. Your keyboard should appear in the device list
  4. Tap it to connect
  5. You'll see a green checkmark when connected
6

Test the connection

Play a few notes on your keyboard. You should see:

  • Notes highlighted on the score as you play
  • Cursor advances when you play correct notes
  • Latency feels instant (USB is typically 5-10ms)

First time connecting? Crescendo will ask you to play a few notes to detect your keyboard's range. Just play the lowest and highest keys, then tap "Done."

5. Troubleshooting

My keyboard doesn't appear in the device list

Try these steps in order:

  1. Check OTG is enabled - This is the most common issue. Go to Settings and verify OTG is turned on.
  2. Verify the adapter is OTG - Make sure your adapter says "OTG" on it. Charging-only adapters won't work.
  3. Try unplugging and reconnecting - Disconnect everything, wait 5 seconds, reconnect.
  4. Power cycle the keyboard - Turn it off and back on while connected.
  5. Try a different cable - About 95% of detection issues are cable-related.
  6. Restart your phone - Sometimes Android needs a fresh start to detect USB devices properly.
My keyboard disconnects after a few minutes

This is almost always the OTG auto-disable feature on OnePlus, Xiaomi, or Oppo phones.

Solutions:

  • Play or touch the screen periodically - Activity resets the 10-minute timer.
  • Re-enable OTG after timeout - Go back to Settings and toggle OTG on again.
  • Check for "OTG timeout" setting - Some phones let you extend or disable the timeout.

Unfortunately, there's no permanent workaround for this on affected phones. The timeout is a battery-saving feature built into the system.

I need to enable Developer Options

To enable Developer Options on any Android phone:

  1. Go to Settings → About Phone
  2. Find Build Number (or "MIUI Version" on Xiaomi, "Software Information" → "Build Number" on Samsung)
  3. Tap it 7 times
  4. You'll see "You are now a developer!" or similar message
  5. Go back to Settings - "Developer Options" will now appear

Once enabled, you can find USB Configuration in Developer Options and set it to MIDI.

I'm using the wrong keyboard port

Many keyboards have multiple USB ports with different purposes:

  • "To Host" / "USB to Computer" - This is the correct port for MIDI.
  • "To Device" / "USB to Device" - This is for connecting USB drives, NOT for MIDI.
  • "USB" (only one port) - Use this one.

Check your keyboard's manual if you're unsure.

Should I use Bluetooth instead?

If your keyboard supports Bluetooth MIDI, it can be a good alternative - especially on phones with aggressive OTG timeouts:

Bluetooth advantages:

  • No cables or adapters needed
  • No OTG timeout issues
  • Cleaner setup

Bluetooth considerations:

  • Slightly higher latency (5-15ms vs 5-10ms)
  • Requires Bluetooth-capable keyboard
  • May need reconnection each session

Supported Keyboard Brands

Crescendo automatically detects keyboards from these manufacturers:

Roland Yamaha Korg Casio Kawai Native Instruments M-Audio Akai Arturia Novation Alesis Nektar

Other USB MIDI keyboards should also work if they follow the standard USB Audio Class specification.

Quick Reference

Phone Brand OTG Setting Location USB Latency
Google Pixel Auto-enabled 5-10ms
Samsung Galaxy Auto-enabled 5-10ms
OnePlus Settings → Additional Settings → OTG 5-10ms
Xiaomi / MIUI Settings → Additional Settings → OTG + Developer Options 5-10ms
Oppo / Realme Settings → Additional Settings → OTG Connection 5-10ms

Related Articles

Still Need Help?

If you've tried everything above and still can't connect, we're here to help.

Email: support@crescendopiano.app

Please include: your phone model, Android version, keyboard model, OTG adapter being used, and what happens when you try to connect.

Response time: 2-3 business days