CTS Verifier MIDI tests

The following tests verify that the Musical Instrument Digital Interface (MIDI) system and the associated C or C++ API (for the Native MIDI Test) and the Java language API (for the JAVA MIDI Test) function as expected.

Follow the steps in the section for your specific Android version.

Required peripherals (Android 16 or higher)

Before running the CTS-V MIDI tests, you must have these peripherals:

• A USB MIDI with associated loopback cables, such as Presonus Audio Box 96 with a standard 5-pin DIN MIDI cable
• A Bluetooth MIDI with associated cables, such as CME WIDI Jack with a 2.5 mm MIDI TRS cable

Examples of MIDI peripherals with associated loopback cables are shown in the following figures:

Figure 1. The front of a USB audio interface with MIDI I/O ports.

Figure 2. The back of a USB audio interface with MIDI I/O ports.

Figure 3. A standard 5-pin DIN MIDI cable.

Figure 4. A Bluetooth MIDI interface with 5-pin DIN.

Figure 5. A Bluetooth MIDI interface with loopback.

Required peripherals (Android 15 or lower)

Before running the CTS-V MIDI tests, you must have a MIDI peripheral with associated loopback cables. Examples of MIDI peripherals with associated loopback cables are shown in the following figures:

Figure 6. The front of a USB audio interface with MIDI I/O ports.

Figure 7. The back of a USB audio interface with MIDI I/O ports.

Figure 8. A standard 5-pin DIN MIDI cable.

Figure 9. A Bluetooth MIDI interface, such as a Yamaha MD-BT01 or a Roland WM-1.

Loopback tests

All the loopback tests send a set of MIDI messages out through the test peripheral, loop back that data, and then monitor the input of that device to check that the data received matches the data that was sent.

All of the following tests must pass before you mark them as passed in the app.

Test USB MIDI loopback

1. On the USB Audio/MIDI interface peripheral, connect the MIDI input to the MIDI output with a standard, 5-pin DIN MIDI cable.
2. Connect the USB Audio/MIDI interface peripheral to the device under test DUT. When the DUT recognizes the connected peripheral, the test screen displays the device names (input and output) and makes the Test USB MIDI Interface button available.
3. Tap Test USB MIDI Interface.
4. Wait for the test to complete, then view the reported results on the test screen.

Test virtual MIDI loopback

No external hardware is required for this test.

1. Tap Test Virtual MIDI Interface.
2. Wait for the test to complete, then view the reported results on the test screen.

Test Bluetooth MIDI loopback (Android 16 or higher)

The following steps describe how to test Bluetooth MIDI loopback on Android 16 or higher:

1. Download and install the MIDI BLE Connect app from Google Play.
2. (optional) If your Bluetooth peripheral supports loopback, for example, the CME WIDI Jack in Figure 5, skip this step. Otherwise, follow these steps:
   1. On the USB Audio/MIDI interface peripheral, connect the Bluetooth MIDI interface to the MIDI input and output connectors on the back of the USB Audio/MIDI interface. The 5-pin DIN connectors on the Bluetooth MIDI interface have specific directionality:
      • The INPUT plug on the Bluetooth MIDI interface must connect to the INPUT jack on the USB Audio/MIDI interface.
      • The OUTPUT plug on the Bluetooth MIDI interface must connect to the OUTPUT jack on the USB Audio/MIDI interface.
   2. Connect the USB Audio/MIDI interface peripheral to the DUT.
3. Run the MIDI BLE Connect app. Scan for the Bluetooth MIDI device. Select this Bluetooth MIDI device.
4. When the DUT recognizes the connected peripheral, the test screen displays the device names (input and output) and makes the Test Bluetooth MIDI Interface button available.
5. Tap Test Bluetooth MIDI Interface.
6. Wait for the test to complete, then view the reported results in the test.

Test Bluetooth MIDI loopback (Android 15 or lower)

The following steps describe how to test Bluetooth MIDI loopback on Android 15 or lower:

1. Download and install the MIDI BLE Connect app from Google Play.
2. On the USB Audio/MIDI interface peripheral, connect the Bluetooth MIDI interface to the MIDI input and output connectors on the back of the USB Audio/MIDI interface. The connectors on the Bluetooth MIDI interface have specific directionality:
   • The INPUT plug on the Bluetooth MIDI interface must connect to the INPUT jack on the USB Audio/MIDI interface.
   • The OUTPUT plug on the Bluetooth MIDI interface must connect to the OUTPUT jack on the USB Audio/MIDI interface.
3. Connect the USB Audio/MIDI interface peripheral to the DUT.
4. Run the MIDI BLE Connect app. Scan for the Bluetooth MIDI device connected to the USB peripheral. Select this Bluetooth MIDI device.
5. When the DUT recognizes the connected peripheral, the test screen displays the device names (input and output) and makes the Bluetooth USB MIDI Interface button available.
6. Tap Bluetooth USB MIDI Interface.
7. Wait for the test to complete, then view the reported results in the test screen.