How to communicate with MIMXRT1060-EVK

[hgiese]

Hello,

I got the above development board, installed MCUXpresso v.11.3.1 on Windows 10, got from the SDK some USB samples, chose evkmimxrt1060_dev_cdc_vcom_bm as project, built and downloaded it - and the programming via "Daplink CMSIS-DAP" worked. Great, no JTAG needed, just a USB cable.

The program itself worked - sort of. It echoed what I wrote, but did not seem to like \n characters. So I tried some other USB projects which maybe I shouldn't have done: When returning to the above project and although I could download it and step through the code Windows device manager never displayed the COM port it had the first run and so I couldn't connect to it and that was it.

The next day (today) it again worked: the COM port appeared - but just once. Since then it never showed up again and Windows (after a moment) put up a message saying "USB device not recognized".

Now, my communication requirements aren't impressive: I only need to type in some commands and look at the answers and I only turned to USB because it seemed the only way to communicate with the board. But maybe there are other possibilities:

- semihosting: I know it works for output but can it be made to work for input, too?

- CMSIS-DAP: I think I read in the user guide (but cannot find it again) that over one line there could be several "communications". Is this true and what would I have to do to be able to do my 'command - response' game?

- ITM: I didn' quite understand the concept and I don't know if it only works with a JTAG adapter (which I don't have) but maybe I am lucky.

- anything else ...

Any help, advice or tip will be greatly appreciated.

Helmut

[jingpan · Accepted solution]

Hi Helmut,

There is a readme.pdf in the project. It has some detail of how to use this example. Please take a look.

The DAPLink has a VCOM for debug information. When the example start, it print "USB device CDC virtual com demo" from this port by default.

Semihost is a special mechanism that can print information through SWD/JTAG debug port. You can switch to semihost by Quickstart Panel->Quick Settings->SDK debug console->Semihost console. It is also bi-direction like UART.

ITM  is used to print trace information via SWO. It can only output.

Regards,

Jing

[hgiese]

Hi jingpan,

thank you so much. I was thinking too complicated - I didn't believe that downloading a program and communicating with it could go over the same wire.

The example you gave me worked perfectly, so now I am on my way.

Thanks again

Helmut