USB CDC ACM Example is not working in interrupt mode

[Deepa Gopinath]

Hi,

On Nordic SDk 15.0, I have observed that USB CDC ACM Example is not working in interrupt mode on nrf52840 Evaluation kit.

But I have tested USB CDC ACM Example in interrupt mode on Nordic SDK 14.2 and its works fine.

To enable interrupt mode, I have modified the USB CDC ACM example of Nordic SDK 14.2 as stated in this link - 

https://devzone.nordicsemi.com/f/nordic-q-a/29641/pca10056-usb-cdc-demo-no-polling

Can you please help us to resolve the issue on Nordic SDK 15.0?

Thanks in Advance

Regards,

Deepa

 

[Deepa Gopinath]

Hi Torbjorn,

Currently we are blocked on this issue. Can you please help us to resolve this issue ASAP?

Thanks in Advance!!

Regards,

Deepa

[ovrebekk]

Hi Deepa

I found the problem on my end. If "DTR" is not enabled, the CDC example will not consider the port opened. I must assume Tera Term is doing this automatically, but if you write your own serial code it might not be set.

Fixing this in my C# example was very easy:

mSerial.DtrEnable = true;
mSerial.Open();

I don't know how it works with QT, but I am sure there is a similar feature to set the DTR state.

Please give this a go, and let me know if it works for you too :)

Best regards
Torbjørn

[Deepa Gopinath]

Hi Torbjorn,

Thanks for the update. I will check this whether we can able to add this changes in QT application.

As stated earlier, without above stated changes, the QT application works fine with STM USB CDC Device. So it will be good if we have a fix in Nordic Application end instead of C# application.

Can you please help us to provide a fix at Nordic USB CDC application end?

Thanks in Advance!!

Regards,

Deepa

[ovrebekk]

Hi 

I tried to make some changes to the driver to make this work. 

I got it to respond without requiring DTR to be set, but the data coming in looks corrupted. 

I will have to do some more testing and get back to you.

Best regards
Torbjørn

[Deepa Gopinath]

Hi Torbjorn,

Thanks for the update. I will be waiting for the solution from the USB CDC Driver End.

Regards,

Deepa