topic Re: USB0 writeEP timing in LPC Microcontrollers

USB0 writeEP timing

adb — Mon, 21 May 2018 15:45:58 GMT

Hello,

I'm trying to download 16MB of data from a flash memory in packets of 512 bytes using the LPC4353. My code is based on HID generic. I'm able to reliably download most of my data, but occasionally I get the odd glitch.

At a low level, I use writeEP to write my packet of data to USB0. I've found that I need a delay between 0.5 and 1 ms between packets. I also wait for a flag which I set in the HID_Ep_Hdlr interrupt callback whenever a USB_EVT_IN event occurs. bInterval has been set to 1ms. I understand that the microcontroller can only send the next packet of data to the PC at the PC's request?

How can I send data as fast as possible without any data loss?

Thanks in advance for any comments,

Alan

Re: USB0 writeEP timing

adb — Tue, 22 May 2018 15:51:07 GMT

Hi again,

Is it possible to detect if a packet has been acknowledged by the host?

Regards,

Alan

Re: USB0 writeEP timing

Hui_Ma — Mon, 28 May 2018 06:03:16 GMT

Hi,

First of all, sorry for the later reply.

If customer had downloaded and refer LPCOpen software for LPC4300 family product about USB bandwidth test demo?

The USB bandwidth test demo located at default project folder:

..\lpcopen_3_02_keil_iar_mcb4357\LPC43xx_18xx\prj_mcb4357\keil\usbd_rom_bwtest

This demo use USB bulk transfer mode with USB host acknowledge.

Wish it helps.

Have a great day,
Mike

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Re: USB0 writeEP timing

adb — Mon, 28 May 2018 15:26:08 GMT

Hi Mike,

Thank you for your comments. This example uses WCID. Is it worthwhile modifying the example to work as HID (I've got a C# PC app that works with HID)?

Is there an app note on this code?

If I understand correctly: this program uses 4 endpoints as opposed to the 2 that were used in the generic HID example and implements a data transfer queue. How do I add data to the dataTosend queue? Are any PC app examples available?

Thanks in advance for your comments,

Regards,

Alan

Re: USB0 writeEP timing

Hui_Ma — Wed, 06 Jun 2018 05:39:13 GMT

Hi Alan,

First of all, sorry for the later reply.

Unfortunately, there without related application note about USB device [bandwidth test] demo project.

There using four endpoints at [bwtest] demo.

If you check here you could found Keil provide USB Stack for MCB4300(LPC4357) board.

There with PC host HID application located at Keil installation folder <HIDClient.exe>.

The related source code also at that folder.

More detailed info, please check below picture:

Wish it helps.

Have a great day,
Mike

Re: USB0 writeEP timing

adb — Thu, 07 Jun 2018 07:47:10 GMT

Hi Mike,

Thank you for getting back to me on this. Can Keil's HIDClient,exe program communicate with a microcontroller that enumerates as WCID? I have my C# program that uses HID and it can't pick it up.

Regards,

Alan

Re: USB0 writeEP timing

Hui_Ma — Mon, 11 Jun 2018 07:49:16 GMT

Hi Alan,

I find USB Band Width test and WCID examples for USB ROM API , which provides a [LPCUsbTest.exe] for PC host.

Please check if that program works or not.

Wish it helps.

Have a great day,
Mike

Re: USB0 writeEP timing

adb — Mon, 11 Jun 2018 08:59:57 GMT

Hi Mike,

Thanks for the link, I will take a look.

Regards,

Alan

From: Hui_Ma <admin@community.nxp.com>

To: Alan Ball <adball24@btinternet.com>

Sent: Monday, 11 June 2018, 8:49

Subject: Re: - Re: USB0 writeEP timing

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Re: USB0 writeEP timing

reply from Hui_Ma in LPC - View the full discussionHi Alan, I find USB Band Width test and WCID examples for USB ROM API , which provides a for PC host.Please check if that program works or not.Wish it helps.

Have a great day,

Mike