"usbd_ble_uart", how can I steer the speed of USB communication?

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

ovrebekk — Tue, 01 Sep 2020 08:11:48 GMT

Hi Mike

Sounds good. In the mean time, have a great vacation 🙂

BR
Torbjørn

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

Michael-1965 — Mon, 31 Aug 2020 13:33:25 GMT

Hi Torbjorn.

You have told me how to control it, but there are still some issues I don't understand. First I have to investigate by myown. Because I'm on vacations until November 2020 we can close the ticket now. If I have any problems I will come back to you.

Thanks for your support.

Regards Mike

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

ovrebekk — Mon, 31 Aug 2020 06:38:58 GMT

Hi Mike

You found a way to get the event running again then?

I will close the case then.

Best regards
Torbjørn

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

Michael-1965 — Fri, 28 Aug 2020 09:56:59 GMT

Hi Torbjorn.

Thanks for your support. I think we can close the ticket for now. I will investigate and open a new ticket if necessary.

Regards
Mike

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

Michael-1965 — Thu, 27 Aug 2020 15:32:23 GMT

Hi Torbjorn

I have called
size_t size = app_usbd_cdc_acm_rx_size(p_cdc_acm);
The size was set to one.

Regards
Michael

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

ovrebekk — Mon, 24 Aug 2020 11:54:08 GMT

Hi Mike

That's a bit odd, resuming execution of app_usbd_event_queue_process() should be enough to get the events running again.

What if you try to call app_usbd_cdc_acm_read(..), to see if there is any pending data in the buffer?

Best regards
Torbjørn

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

Michael-1965 — Fri, 21 Aug 2020 15:27:18 GMT

Hi Torbjorn.

Thanks, I have already done a try, it works better now. I will improve my implementation now.
But I have to use the event APP_USBD_CDC_ACM_USER_EVT_TX_DONE to bring the event APP_USBD_CDC_ACM_USER_EVT_RX_DONE back to work.

Is there another way to re-enable APP_USBD_CDC_ACM_USER_EVT_RX_DONE?

Best regards and enjoy the weekend.
Mike

RE: "usbd_ble_uart", how can I steer the speed of USB communication?

ovrebekk — Thu, 20 Aug 2020 13:43:16 GMT

Hi Mike

The USB protocol has it's own method for flow control where one side of the link can NAK packets if the internal buffers are full.

A simple way to make this happen from the application side is simply to stop calling the app_usbd_event_queue_process() function from the while loop in main. Then you will stop reading out data from the USB driver, and eventually it will start NAK-ing any incoming packet from the USB host.

In other words you should stop calling this function once you get the RESOURCES error from the SoftDevice, and then start calling it again once you have successfully sent some data over the SoftDevice.

Best regards
Torbjørn