[solved] 18F47J53 dual USB mode : uart /hid

[spilz]

Hello

I would like to know if there is a way to switch the USB mode from hid to uart and from uart to hid.
I use uart as debug, but now I need to use the USB port as hid keyboard, but still want to be able to use uart for debug when needed.
A solution with a selection on start is ok for my use (if a jumper is set on startup -> uart, else -> hid).

Someone know how to do or if it's not possible ?

Thanks for your help.

Regards

[Ttelmah]

I'd setup the device in dual mode (composite).
There is nothing to stop you setting the device up in composite mode, so it is both a HID and CDC device.
There is a kb/mouse example composite device supplied with the compiler.

[spilz]

Thanks for your reply

I thought it was not possible, so it's a very good news if I can do it
Actually I tried to do it with the example kb/mouse but I thought it was possible only because both are hid, i don't see where I composite mode is set.

[Ttelmah]

You would need to take a composite descriptor, like the one here:
<https://bitbucket.org/sparkbuzz/pic32_usb.x/src>

and put the CDC and HID values your device wants in place of the values used.

The example shows how you talk to the endpoints.

[spilz]

I saw an other exemple file which seems doing exactly what I need : ex_usb_hid_and_cdc.c
I'm able to compile, but only uart work, hid seems not working :(
I maybe miss understand Something and what hid should do on this exemple...

[Ttelmah]

The HID in that example just sends the ADC value as an output, and operates three LED's from the value received.

[spilz]

ho I see,
I thought it act as a keyboard :(

I tried to change the my_hid_demo(void) function by a KB function, but it doesn't work.

I guess the solution is the composite descriptor you talk about but I don't know enough USB to understand it :(

[spilz]

I don't really understand why usb_desc_key_cdc.h doesn't work as descriptor :(

[spilz]

I found an example I didn't see before : ex_usb_keyboard_and_cdc.c

It does exactly what I need

It works alone, but when I try to add it on my personal project, keyboard seems never be released, I can change the key pressed, but can't release it :(

Any idea what can do it ? or solve it ?

regards

[Ttelmah]

You do understand how a keyboard works in Windows?.

Note how the keyboard_task in the example puts the packet, even if there is no character to send.

[spilz]

If I understand right, the HID should send the key which are pressed, if no key are pressed, it should send only null value.

In my personal code, I try to ask only one time keyboard_task but the key stays like pressed.

I tried to call an other time keyboard_task with only null value, but doesn't solve the issue :(

[Ttelmah]

You need to send three null bytes, not just a single null.

The packet sent has the modifier keys, then the padding, and finally the key array. Both the modifier key value, and the key array have to be 0 to say everything has released, so a three byte packet.
So
tx_msg[2]=0;
tx_msg[0]=0;
Then the usb_put_packet.

[spilz]

Ok, I found my mistake:
I sent the second usb_put_packet with null values too fast, adding delay_ms(10) solve the issue

Now I need to understand how I can do several keys pressed:

LeftShift + LeftWindows + LeftAlt + 'b'

But I don't know where to find the value of each key.

For LeftShift + LeftAlt + 'b' , I tried to send HID values:

[Ttelmah]

The shift keys are the key 'modifiers'. Byte 0 in the transmission.

[spilz]

Thank you Ttelmah, it works now