nRF52833: using USB_CDC_ACM Example from SDK17.1.0 , but data cannot be received from the usb serial port

[wei bing]

Hi,

Now I'm going to use 52833 USB_CDC_ACM  , but there is no suitable type in SDK17.1.0. It's just have pca10056 .So I port to 52833 based on the 52840_pca10056 routines. 

And I download the hex into the 52833. At present, the computer can recognize this USB serial port.

When I open the serial port assistant, there is no response when I want to send or receive data. I don't know where is the problem.

The serial port appears to be recognized, but is not programmatically manipulated.

When I debug, I go to the following place

If I comment two lines , and I wrote the UsbCdcWrite function.

That my serial port assistant will receive some data,but they are all 0

So I would like to know if there is anything I should pay attention to in porting routines？ how to solve such problems？how to get me to port the program correctly？

Regards,
Wei

[Vidar Berg]

Hello Wei,

Attached below is a 'pca10100' configuration I made for the \examples\peripheral\usbd_cdc_acm. Please try and run this project to see if it works for you as well (I did some quick tests with it on a nRF52833DK I have here). I did not make any code changes, only device related changes (updating memory layout, startup files,changing target device name, etc).

52833 project + precompiled hex :

0702.usbd_cdc_acm.zip

Regards,

Vidar

[wei bing]

Hello Vidar,

Thank you for your answer, I have now solved this problem by turning on the DTR on the serial assistant.But I still want to know what this DTR does, and why does it have to be turned on.

Regards,
Wei

[Vidar Berg]

Hello Wei,

I see. The serial clients I typically use will set the DTR when I open the com port. I believe this is the default behavior for most clients. Though you are apparently not the first one to encounter this:  USB cdc acm driver dependency on DTR