topic USB ROM API Custom Device Class in LPC Microcontrollers

USB ROM API Custom Device Class

mrarkwright — Mon, 13 Feb 2017 14:18:40 GMT

I'm implementing a USB MIDI device. My in-endpoint works fine but i can't get the out-endpoint to receive data. I registered my endpoint handler with

USBD_API->core->RegisterEpHandler(g_hUsb, 2, epOutHandler, NULL);

As per documentation the handler should receive USB_EVT_OUT events and USB_EVT_OUT_NAK events should be deactivated by default. However my handler is only ever called with USB_EVT_OUT_NAK and never with USB_EVT_OUT.

Also, is my approach correct to read the received data with

USBD_API->hw->ReadEP(hUsb, 0x01, pData);

in my handler whenever it is called with an USB_EVT_OUT event?

This is my configuration descriptor in case it matters:

ALIGNED(4) uint8_t USB_ConfigDescriptor[] = {
0x09, 0x02, 0x44, 0x00, 0x01, 0x01, 0x00, 0x80, 0x3C,   // Config, 1 interface
0x09, 0x04, 0x00, 0x00, 0x02, 0x01, 0x03, 0x00, 0x03,   // Interface0, 2 EPs, Audio, Midi
0x07, 0x24, 0x01, 0x00, 0x01, 0x32, 0x00,               // CS Interface (midi)
0x06, 0x24, 0x02, 0x01, 0x01, 0x00,                     // jack, in, embed, nr1
0x09, 0x24, 0x03, 0x01, 0x02, 0x01, 0x01, 0x01, 0x00,   // jack, out, embed, nr2
0x09, 0x05, 0x01, 0x03, 0x40, 0x00, 0x02, 0x00, 0x00,   // EP, out, nr1, interrupt
0x05, 0x25, 0x01, 0x01, 0x01,                           // CS EP, jack1
0x09, 0x05, 0x82, 0x03, 0x40, 0x00, 0x02, 0x00, 0x00,   // EP, in, nr1, interrupt
0x05, 0x25, 0x01, 0x01, 0x02,                           // CS EP, jack2
0x00
};

Re: USB ROM API Custom Device Class

jeremyzhou — Thu, 16 Feb 2017 01:32:52 GMT

Hi Jannik Theiß,

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.

Before answer your question, I was wondering if you can tell what exactly chip you use.

Have a great day!

Ping

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Re: USB ROM API Custom Device Class

mrarkwright — Sun, 19 Feb 2017 10:41:23 GMT

Hi jeremyzhou,

I'm using a LPCXpresso4337 evaluation board. So the Chip is a LPC4337.

Re: USB ROM API Custom Device Class

jeremyzhou — Mon, 20 Feb 2017 02:37:07 GMT

Hi Jannik Theiß,

Thanks for your reply, and I was wondering if you can share the demo, then I can replicate the issue on my board.

I'm looking forward to your reply.
Have a great day,
Ping

Re: USB ROM API Custom Device Class

Eli_H — Mon, 28 Aug 2017 19:06:10 GMT

Jannik:

Did you ever get this working? If so, Can you post your results?