Sending ASCI from MCU to PC

[snabilat]

hi everyone
Is it possible for me to send the ASCI codes of some keys of a PS/2 keyboard from a 89C51 to a PC or should i search the SCAN codes, what about the CLK , should that too be sent from the MCU.
if anyone had a subroutine i would be thankful.
Thanks in advance.

 

[C-Man]

Read here:



best regards

 

[snabilat]

thanks for ur help, actually i wanted to automatically contole an application with a MCU.
The logic i have created is to first send the code of " Alt F" than the code of "S" than the code for "Space bar"
and than the code for "ESC".These codes will be stored in the ROM of the MCU which should send it to the PC after predefined delay.
WHAT I WANTED TO KNOW IS an easiy way to accomplish this,
and if i sent the codes ASCI equivlent would it work.
unfortunately the discussions u reffered me to, diden't provide much help in this respect.

 

[Ace-X]

1. Check this **broken link removed**
for good description along with ASM sources for PIC.
2. You should send SCAN codes.
3. CLK for PS/2 generated by connected device (uC in your case), but it also can be altered by PC to select transmit mode. Read above resource for details.

 

[snabilat]

thanks ACE the site u gave helped a lot, and what i came to know is that the MCU should send the scan codes as well as a synchrozed clk. with it the clk should be from 10-25Khz.
will this variation in the clk. matter with the data sent to the PC.

 

[Ace-X]

with it the clk should be from 10-25Khz.
will this variation in the clk. matter with the data sent to the PC.

This variation does not matter, because PC latches every new bit from data line by active edge on clock. And because you control serial clock on uC side, then you also control when data will be latched. As to this stated frequency, the practise shows that it can be variable to both side in wide range.