How to use USBCDC and HID together?

[yuan910715]

Hi I want to use CH552 to finish a 6 keys keyboard , I write the code reference to the example HidKeyboard , and it works fine. I want to develop a PC software , it can communication to CH552, so I can define the keyboard button to any key ,no need to upload the program again to change the key, I use USBCDC to finish serial communication , but HidKeyboard is not work How to use USBCDC and HID together? Or is there any other way? Thanks a lot

[DeqingSun]

It is not a good practice to use CDC just for reconfigure the keyboard map. Adding HID raw report should be a better choice.

Take a look at https://github.com/yswallow/CH552duinoKeyboard

If you still want to use CDC and HID together, you may check

https://github.com/Noteolvides/CubeTouch/tree/main/Examples/CDC_KEYBOARD

I've not tested any of the referenced project and I don't know how they work or if they were buggy.

[yuan910715]

I tried https://github.com/Noteolvides/CubeTouch/tree/main/Examples/CDC_KEYBOARD it works well, next I will develop a PC program to reconfigure the keyboard map , so I can give the 6-key keyboard as a gift to my friend , and they can easily reconfigure the keyboard map Thank you!!

I'm a little confused: what do you mean 'Adding HID raw report'?Is that modify the arduino code when need reconfigure the keyboard map?

[DeqingSun]

The same hid endpoint can do keyboard, mouse and raw hid communication with a different report id. You would be able to use hid API on computer to do 2 way communication. That is how Marco pad keyboard do remap.

[yuan910715]

I have completed a small three-key keyboard, and can reconfigure the keyboard map through the serial port. Now waiting for the production of PCB , I will show the pictures and open source in a few days， please wait.. Thanks!!

[DeqingSun]

It seems you used https://github.com/Noteolvides/CubeTouch/blob/main/Examples/CDC_KEYBOARD/CDC_KEYBOARD.ino as example? I'm not sure if there will be memory overlapping issue because the setting was "USER CODE w/148 USB Ram" and the Ep3Buffer is outside the reserved space. The Ep3Buffer may be overlap with other variables in xdata. You shall double check the .map file before you ship your code to your user or client.

[yuan910715]

Hi, I used https://github.com/Noteolvides/CubeTouch/blob/main/Examples/CDC_KEYBOARD/CDC_KEYBOARD.ino as example. I see the Ep3Buffer is outside the reserved space. But why I compiled two .hex file ,one is Tools--> USB Settings--> USER CODE w/148 USB Ram and the other is USER CODE w/266 USB Ram , can both works well ,I don't know why.

[DeqingSun]

The memory overlap may not have immediate problem, bugs will be triggered in some boundary conditions.

Using 266 will be safer and avoid the problem.

[yuan910715]

hi , I completed my DIY project , https://github.com/yuan910715/3keys Thank you very much, I can't do it without your help.