USB event is not triggered every time a data array is being received

RE: USB event is not triggered every time a data array is being received

ovrebekk — Fri, 11 Dec 2020 09:49:37 GMT

I am happy to hear you figured it out 🙂

If you have more questions just let me know.

Best regards
Torbjørn

RE: USB event is not triggered every time a data array is being received

masterLee — Thu, 10 Dec 2020 10:33:13 GMT

Hi, I changed READ_SIZE parameter from 4 to 3 and it works fine. The program was waiting for four bytes and I was sending 3 every time so 1 in 4 didn't send back nothing.

Thank you for your support!

RE: USB event is not triggered every time a data array is being received

ovrebekk — Thu, 10 Dec 2020 09:21:10 GMT

1. Have you changed the READ_SIZE parameter?

You say you send your command continuously, how often do you send it?

2. The app_usbd_event_queue_process() function should be called once every time you go through the main while loop, before you go to sleep normally. You shouldn't have to call it after issuing a write, or anywhere else in the code.

The reason this is called from the main loop is to avoid running higher level USB processing in interrupt context, which would block other interrupts from being executed.

Best regards
Torbjørn

RE: USB event is not triggered every time a data array is being received

masterLee — Wed, 09 Dec 2020 14:41:21 GMT

Hi, yes I explicitly set the DTR signal in both terminal applications including docklight.

1. Is there something in the code I have posted that may result in this behavior? Because otherwise it doesn't make sense to me...

2. Also, could you please explain me when should I use while (app_usbd_event_queue_process());

I don't understand why events from the queue are not processed automaticaly and a function must trigger it

RE: USB event is not triggered every time a data array is being received

ovrebekk — Wed, 09 Dec 2020 13:52:16 GMT

Most likely the problem here is that your non working terminal is not setting the DTR signal, which is needed by the CDC class to open the serial port.

In some terminals this is done automatically, while in others it is not. Some terminals require you to set it manually, as described in this case.

Do you know if the docklight terminal allows you to set this signal?

Best regards
Torbjørn