Serial Communication with nrf5340 and Windows 10

[mhandford]

How do I get to the point that I can print a simple "Hello World" on a terminal from a custom board?

I have a custom board the is based on the nrf5340. Specifically, I am using the Raytac MDBT53-1M module. I am able to program the board and I have verified that the blinky sample functions normally. However, I cannot figure out how to get serial communication working with the USB.

I have attempted to run the zephyr cdc_acm sample but when I flash the board, windows won't recognize it as a USB device. I have added the following lines to the prj.conf file:

CONFIG_USB_COMPOSITE_DEVICE=y

CONFIG_CDC_ACM_IAD=y

as suggested on CDC_ACM USB not recognized by windows as serial port · Issue #17266 · zephyrproject-rtos/zephyr · GitHub but this doesn't seem to fix the problem.

[Einar Thorsrud]

Hi,

I did a quick test on my end using the following device tree overlay:

/ {
	chosen {
		zephyr,console = &cdc_acm_uart0;
	};
};

&zephyr_udc0 {
	cdc_acm_uart0: cdc_acm_uart0 {
		compatible = "zephyr,cdc-acm-uart";
	};
};

And with that I got terminal over CDC ACM working on Windows 10. Does it work if you do this on your end? If not, can you share the entier project with your modifications?

[mhandford]

Windows still doesn't recognize the usb device.

I've swap to trying the usb console sample that seems like a simpler sample to work with.

I will attach the project files. 6064.console.zip

[mhandford]

I have uploaded the code to the nrf5340dk and it seems to work. So maybe it's an issue with the board? Are there certain pin requirements for CDC ACM to work?

[mhandford]

I seem to have crossed my positive and negative inputs on the usb lines on the board. I used your supplied code, and it works perfectly with puTTy. Thanks for your help trouble shooting.

As a follow up, is there any way to get nrf connect to detect the board as a device? While I can get the puTTy terminal to see the board, it doesn't show up under "connected devices" in vscode.

[Einar Thorsrud]

Hi,

I am glad to hear you got it working. Unfortunately you cannot get just a USB CDC device showing up in VS Code, as it requiers J-Link (see the documentation for details).