[CDC ACM USB Example] DTR Issue

RE: [CDC ACM USB Example] DTR Issue

Kenneth — Tue, 30 Jul 2024 08:25:34 GMT

Hello,

I would say that using DSR/DTR as flow control is not very common (using RTS/CTS is common if flow control is used). By default, the serial teminal software (e.g putty, tera term and others) raises the DTR line when a serial connection is established, indicating that it is ready for communication (this happens for instance automatically if DSR/DTR flow control is not used). If you want to enable flow control of the DTR line from the serial terminal software I recommend to refer to the specific software for help.

Kenneth

RE: [CDC ACM USB Example] DTR Issue

seongmincho — Mon, 22 Jul 2024 01:07:17 GMT

In my case, COM12 is indentified as 'Zephyr CDC ACM sample'. so, I connected to COM12 for PuTTY and set the log debugging to COM10

The CDC_ACM example works very well. However, what I am curious about is that if I set the flow control to DSR/DTR in PuTTY, it does not proceed to DTR set. Currently, I am programming with the flow control set to None.

RE: [CDC ACM USB Example] DTR Issue

Kazi Afroza Sultana — Fri, 19 Jul 2024 15:26:25 GMT

Hello,

Could you please show '' In my case, COM11 was identified as 'Zephyr CDC ACM sample'. I connected to COM11 using PuTTY and set the log debugging to COM6.'' this, how you have implemented this on putty?

RE: [CDC ACM USB Example] DTR Issue

seongmincho — Tue, 16 Jul 2024 07:11:50 GMT

I think we shouldn't set the flow control in PuTTY to 'DSR/DTR' because we have configured it with the code below. This is just my personal theory.

uart_line_ctrl_get(dev, UART_LINE_CTRL_DTR, &dtr);
uart_line_ctrl_set(dev, UART_LINE_CTRL_DCD, 1);
uart_line_ctrl_set(dev, UART_LINE_CTRL_DSR, 1);
uart_line_ctrl_get(dev, UART_LINE_CTRL_BAUD_RATE, &baudrate);

RE: [CDC ACM USB Example] DTR Issue

seongmincho — Mon, 15 Jul 2024 01:44:05 GMT

[quote userid="15146" url="~/f/nordic-q-a/112927/cdc-acm-usb-example-dtr-issue/493781"]Do you see any difference if you change flow control setting in PuTTy?[/quote]

If the Flow Control is not set to 'DSR/DTR', it proceeded to DTR set!

Isn't this contradictory?

hmm... what's wrong?

RE: [CDC ACM USB Example] DTR Issue

Sigurd — Sun, 14 Jul 2024 23:30:33 GMT

Ok, so now you are interfacing with the right COM port. Do you see any difference if you change flow control setting in PuTTy?

RE: [CDC ACM USB Example] DTR Issue

seongmincho — Fri, 12 Jul 2024 13:54:02 GMT

thank you for answer! I feel that your help is invaluable.
but.. In my case, COM11 was identified as 'Zephyr CDC ACM sample'. I connected to COM11 using PuTTY and set the log debugging to COM6. Despite this, I couldn't get past the while loop.

-Blow is log debugging:

*** Booting nRF Connect SDK v3.5.99-ncs1 ***
[00:00:00.250,518] <inf> cdc_acm_echo: Device name: cdc_acm_uart0
[00:00:00.250,549] <inf> cdc_acm_echo: Device config address: 0x20000438
[00:00:00.250,549] <inf> cdc_acm_echo: Device API address: 0xbae4
[00:00:00.250,579] <inf> cdc_acm_echo: Device state address: 0x2000026c
[00:00:00.250,579] <inf> cdc_acm_echo: Device private data address: 0x20000000
[00:00:00.250,762] <inf> cdc_acm_echo: usb_enable >>>> err:0
[00:00:00.250,762] <inf> cdc_acm_echo: Wait for DTR
[00:00:00.250,793] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.250,793] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.254,791] <inf> usb_cdc_acm: Device suspended
[00:00:00.350,860] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.350,891] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.352,874] <inf> usb_cdc_acm: Device resumed
[00:00:00.450,958] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.450,958] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.551,055] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.551,055] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.587,097] <inf> usb_cdc_acm: Device configured
[00:00:00.651,153] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.651,153] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.751,251] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.751,281] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.851,348] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.851,348] <inf> cdc_acm_echo: DTR >>>:0
[00:00:00.951,446] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:00.951,446] <inf> cdc_acm_echo: DTR >>>:0
[00:00:01.051,544] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:01.051,544] <inf> cdc_acm_echo: DTR >>>:0
[00:00:01.151,641] <inf> cdc_acm_echo: uart_line_ctrl_get >>> err:0
[00:00:01.151,641] <inf> cdc_acm_echo: DTR >>>:0

- Blow is Device Manager:

RE: [CDC ACM USB Example] DTR Issue

Sigurd — Thu, 11 Jul 2024 16:32:20 GMT

Hi!

1) Make sure that you have connect the USB cable to USB port on the long side of the DK named "nRF USB".

2) COM10 is wrong, since that's the J-link port.

It should be the USB Serial Device, that have Bus reported device description "Zephyr CDC ACM sample"