USBX Host HID Keyboard Issues

Hi Jamie-
What source are you using to find the values you expect for the keys? Are you looking at a standards doc? Does it define the key values differently if num lock is on or off?

On the key held issue- in 2b it looks like you need to check for both press key and release key events. If a release key event hasn't been received, you could mask off any additional press key events from that key. Is that a possibility?

Warren

Hi Warren - Thanks for your reply.

I am using the USBX HID Host function ux_host_class_hid_keyboard_key_get() to retrieve the key events. This function populates both a key event and keyboard status. I used the USBX Host Class HID Module R11AN0236EU0100 as a guide for implementing this in my application.

I can't find any documentation the specifies expected return values for ux_host_class_hid_keyboard_key_get(), and I can't find any reference to press and release events. Perhaps I am missing something because implementing per your suggestion makes sense, but I don't see how the USBX framework provides access to that info.

Hi Jaime,

We have a bug in the key mapping array we use to return characters from that API. This is what that array looks like:

/* Define USB HID keyboard mapping tables. */

UCHAR ux_host_class_hid_keyboard_regular_array[] =
{
0,0,0,0,
'a','b','c','d','e','f','g','h','i','j', 'k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
'1','2','3','4','5','6','7','8','9','0',
0x0d,0x1b,0x08,0x07,0x20,'-','=','[',']',
'\\','#',';',0x27,'`',',','.','/',0xf0,
0xbb,0xbc,0xbd,0xbe,0xbf,0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,
0x00,0xf1,0x00,0xd2,0xc7,0xc9,0xd3,0xcf,0xd1,0xcd,0xcd,0xd0,0xc8,0xf2,
'/','*','-','+',
0x0d,'1','2','3','4','5','6','7','8','9','0','.','\\',0x00,0x00,'=',
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
};

This array is defined in an encrypted source file so you can fix it there, but it is not statically defined so you can just fix the array in your program before you ever get a key. To do this you should add these lines to some place soon after main:

extern UCHAR ux_host_class_hid_keyboard_regular_array[];

ux_host_class_hid_keyboard_regular_array[80] = 203;


In the next version of the SSP there is a way that you can access and define this array in source code so that you can define your own key mapping without having to poke values into the array.


On your desire to add key-up events, there is a lower level API that you can call into to see these and all events on the keyboard, however they are difficult to use and not very well documented. In the near future we plan to augment the HID host module guide example by calling into this lower level API so that these types of events are visible.

Hi Dale -

The array modification worked to correct the left arrow functionality - thank you!

Any information you can provide about the lower level API would be very appreciated. As it stands, the HID Keyboard functionality is unacceptable for our application.

Hi Dale -

Checking in again to see if you can provide any more information or example for using the lower level HID API you referenced in your previous post? Thank you.

Hi Dale -

Just pinging you again to see if you have any updates on this example you could provide? Thank you.

Hey Dale, I have the same issue. Any progress on the class driver? Bill

Bill

Dale is no longer with the company. Anyway, it sounds like this is something that Dale expected the customer to develop on their own.

Janet