Support request: GENERAL PIANO 88035 USB MIDI Keyboard (VID: 0x7777, PID: 0x8899) is not detected

[Mongoose80]

Hello,

I’m trying to use a USB MIDI keyboard “GENERAL PIANO 88035” (VID: 0x7777, PID: 0x8899) with Arduino and the USB Host Shield 2.0 library, but unfortunately, it is not recognized as a MIDI device.

What I’ve done:

I have manually added the VID and PID to the relevant places in the library (such as setupDeviceSpecific()).
The device is visible in Windows as “GENERAL Piano” and is detected as a USB composite device.
MIDI software (like MIDI-OX) on Windows can see and use the keyboard.
However, using the USB Host Shield on Arduino, it doesn’t show up as a MIDI device, and no MIDI messages are received.
Device info and descriptor:

I have extracted the full USB device descriptor using USB Device Tree Viewer:

---------------------- Device Descriptor ----------------------
bLength : 0x12 (18 bytes)
bDescriptorType : 0x01 (Device Descriptor)
bcdUSB : 0x110 (USB Version 1.1)
bDeviceClass : 0x00 (defined by the interface descriptors)
bDeviceSubClass : 0x00
bDeviceProtocol : 0x00
bMaxPacketSize0 : 0x08 (8 bytes)
idVendor : 0x7777 (Unknown Vendor)
idProduct : 0x8899
bcdDevice : 0x0100
iManufacturer : 0x00 (No String Descriptor)
iProduct : 0x01 (String Descriptor 1)
*!*ERROR String descriptor not found
iSerialNumber : 0x00 (No String Descriptor)
bNumConfigurations : 0x01 (1 Configuration)

------------------ Configuration Descriptor -------------------

bLength : 0x09 (9 bytes)
bDescriptorType : 0x02 (Configuration Descriptor)
wTotalLength : 0x0065 (101 bytes)
bNumInterfaces : 0x02 (2 Interfaces)
bConfigurationValue : 0x01 (Configuration 1)
iConfiguration : 0x00 (No String Descriptor)
bmAttributes : 0x80
D7: Reserved, set 1 : 0x01
D6: Self Powered : 0x00 (no)
D5: Remote Wakeup : 0x00 (no)
D4..0: Reserved, set 0 : 0x00
MaxPower : 0x32 (100 mA)

    ---------------- Interface Descriptor -----------------

bLength : 0x09 (9 bytes)
bDescriptorType : 0x04 (Interface Descriptor)
bInterfaceNumber : 0x00 (Interface 0)
bAlternateSetting : 0x00
bNumEndpoints : 0x00 (Default Control Pipe only)
bInterfaceClass : 0x01 (Audio)
bInterfaceSubClass : 0x01 (Audio Control)
bInterfaceProtocol : 0x00
iInterface : 0x00 (No String Descriptor)

    ---------------- Interface Descriptor -----------------

bLength : 0x09 (9 bytes)
bDescriptorType : 0x04 (Interface Descriptor)
bInterfaceNumber : 0x01 (Interface 1)
bAlternateSetting : 0x00
bNumEndpoints : 0x02 (2 Endpoints)
bInterfaceClass : 0x01 (Audio)
bInterfaceSubClass : 0x03 (MIDI Streaming)
bInterfaceProtocol : 0x00
iInterface : 0x00 (No String Descriptor)

    - MIDI Adapter Class specific MS Interface Descriptor -

bLength : 0x07 (7 bytes)
bDescriptorType : 0x24 (Class Specific Interface Descriptor)
bDescriptorSubtype : 0x01 (MS Header)
bcdADC : 0x0100
wTotalLength : 0x0041 (65 bytes)

    ---------------- MIDI IN Jack Descriptor --------------

bLength : 0x06 (6 bytes)
bDescriptorType : 0x24 (Class Specific Interface Descriptor)
bDescriptorSubtype : 0x02 (MIDI_IN_JACK)
bJackType : 0x01 (Embedded)
bJackID : 0x01 (ID=1)
iJack : 0x00 (No String Descriptor)
...
and so on (full descriptor attached)
Summary:

The device uses the standard Audio/MIDI Streaming interface (InterfaceClass: 0x01, SubClass: 0x03)
Endpoints are Bulk IN/OUT, standard sizes
No string descriptors are available
Questions:

Is there anything in the USB Host Shield 2.0 library that would prevent full class-compliant MIDI devices with custom VID/PID from being recognized?
Are there any extra steps or patches required to support devices like this that do not have string descriptors or use generic vendor IDs?
Do you have any debug advice, or is it possible to implement a “force class” detection based only on Interface Class/SubClass rather than VID/PID?
Thank you for your project and for any advice you can provide!

I am happy to provide logs, debug output, or further device info if needed.

Best regards,

Alex.

usb.txt

[YuuichiAkagawa]

Please report the results of using USB_desc and USB_MIDI_desc.

The USB MIDI driver is implemented so that any device conforming to the class-compliant MIDI devices can be connected without modifying the source code. It doesn't check the VID or PID.

However, there are a certain number of devices that can be used on Windows or Mac but cannot be used in other environments.

[Mongoose80]

SB_desc

Start

USB_MIDI_desc.

Start

[YuuichiAkagawa]

Is your USB Host Shield working properly?
I can't help you because it's not being recognized by the USB layer.

[Mongoose80]

Hello,

The issue remains the same: my current USB Host Shield does not start up (“OSC did not start” error in the USB_desc and USB_MIDI_desc examples).

I have ordered a new USB Host Shield. As soon as it arrives, I will repeat the tests and send you the detailed output from both the USB_desc and USB_MIDI_desc examples.

Thank you for your help and patience!

[Mongoose80]

Hello,

Board Descriptions:

Arduino Mega 2560 WiFi + ESP8266 Board

Controller: ATmega2560, with onboard ESP8266EX WiFi module and USB-TTL converter (CH340G).
The board features pin headers for accessing the ESP8266 outputs.
It allows flexible interaction between three functional units: ATmega2560, ESP8266EX, and USB-TTL.
The DIP switches configure operation modes, letting you use each unit independently or in different combinations:
Mode 3: Switches 3 and 4 ON, the rest OFF — the board works as a classic Arduino Mega 2560.
Other modes: ESP-only, independent, Mega <-> ESP, etc.
USB Host Shield 2.0 (MAX3421E, generic Chinese version)

Standard layout designed for compatibility with both Arduino Uno and Mega 2560.
No DIP switches or jumpers for Mega compatibility, connects to SPI via standard headers and ICSP.
My DIP switch settings are:

Switches 3 and 4 ON, all others OFF. This means the Mega is in “classic Arduino Mega mode,” fully isolated from ESP8266 or any additional serial routing.

What I’ve Tried
I have tested two different pairs of boards:
2 different Arduino Mega 2560 WiFi+ESP boards
2 different USB Host Shield 2.0 boards
In all combinations, the behavior and errors are the same.
Test Results
board_qc:

Circuits At Home 2011
USB Host Shield Quality Control Routine
Reading REVISION register... Die revision invalid. Value returned: 00
Unrecoverable error - test halted!!
0x55 pattern is transmitted via SPI
Press RESET to restart test
USBH_MIDI_desc:

IStart
OSC did not start.
Summary
DIP switches: 3 and 4 ON, others OFF (“Mega Standalone” mode)
Both boards are brand new.
I tried two different Mega+Shield pairs.
Both USB Host Shields are firmly attached and all pins/ICSP have contact.
The issue is always the same:
board_qc stops after “Reading REVISION register… Die revision invalid. Value returned: 00”
USBH_MIDI_desc always says “OSC did not start”
If needed I can provide clear photos of the boards (top and bottom) and current wiring/installations.
If you have any suggestions or can clarify if there are any known compatibility issues with this Mega2560+WiFi board and the USB Host Shield, please let me know.

Thank you!

[Mongoose80]

[YuuichiAkagawa]

The original USB Host Shield manual can be found here.
USB Host Shield Hardware Manual
We don't know how third-party products work, so we can't help you.

For reference, my configuration on Arduino UNO R3 is shown below.

@Lauszus , can you put the hardware manual on the Wiki?

[xxxajk]

It's worth noting that the later models of the shield have the ability to control the VBUS output. That's another way to check for cheap clones.
Be also aware the the chip from clones have been seen as fake MAX3421E too, frustrating users.
My guess here, is that some, or all the chips are fakes, reclaimed, or not to actual spec.