PS/2 Woes...

[bsodmike]

Hello all,

I've gotten to the point where I can see some data coming off the PS/2 interface (with respect to the mouse) and according to the page by Adam Chapweske, bits 4 and 5 on the first received byte tell you the direction in which the mouse is moving. Actually this is the 9th bit, i.e.:

  8          7      6     5     4   3   2   1   0
-255      128   64   32   16   8   4   2   1

hence a 9 bit 2's complement integer.

So as a test I had my PIC test these 2 bits for X/Y and display it on an LCD:

**broken link removed**

The annoying part comes here - it sits @ showing '+' only, which means that both bits are 0 and this is confusing.

To try and help me sort this out I've developed a little program in python (with GUI) which will grab these packets via RS232 and display it on screen and log the data to a log file.

Any ideas at all would be greatly appreciated. Oh, I'm using unsigned chars to store them as well (on the PIC, in C at least).

Cheers, Mike

 

[Neiwiertz]

search google for ps/2 protocol

i grabbed in five minutes

http://www.networktechinc.com/ps2-prots.html
http://www.win.tue.nl/~aeb/linux/kbd/scancodes.html#toc14
**broken link removed**
https://www.electro-tech-online.com/custompdfs/2006/03/PS2_TO_USB.pdf
**broken link removed**
www.jkmicro.com/documentation/pdf/PS2Keyboard_EN.pdf
**broken link removed**

let know if it was usefull in your case :roll:

 

[bsodmike]

Thanks dude, I only saw your reply today d'oh. I got this sorted last Wednesday 'yay'. The timing is very sensitive hehe...

Cheers, Mike