pic as ps/2 keyboard

[JEC]

Here's a code snippet to transmit PS/2 data:

In this case, dataout is an array of bytes I may want to send to the computer.

Odd parity is NOT the value of all bits XOR'ed together.

Good luck!

John


* * *
for x = 0 to 7
if dataout[x] <> 0 then
sendthis = dataout[x]
parity = not(sendthis.0 ^^ sendthis.1 ^^ sendthis.2 ^^ sendthis.3 ^^ sendthis.4 ^^ sendthis.5 ^^ sendthis.6 ^^ sendthis.7)
sendthis = sendthis << 1 'move over to insert start bit
sendthis.0 = 0 'start bit
sendthis.9 = parity
sendthis.10 = 1 'stop bit
shiftout kbddata,kbdclk,4,[sendthis\11]
dataout[x] = 0
endif
next x

[mischl]

hello john

thanks for your support.

i work with a similar code. so i have some additional questions :

- which osc speed do you use? - i have a 16f876 with 4M
- have you defined a shift_pauseus? - i try it . around 40us seems best
- how long do you wait until you send the release code (F0) after the button press comand? - i don't wait
- how looks your hardware setup? - 2 transistors at portc with pull up works at best. nod good because i get different chars... when i only take pullups instead the transisitors, after connect the keyboard it wouldn't be initialized.
- what are you doing at the booting from the pc?

best regards

[JEC]

- which osc speed do you use? - i have a 16f876 with 4M

'628 @ 20 MHz

- have you defined a shift_pauseus? - i try it . around 40us seems best

I used 50 uS

- how long do you wait until you send the release code (F0) after the button press comand? - i don't wait

In my particular application, I sent a 'make' code at keydown and a 'break' code at keyup. So the waiting time was up to the buttonpusher.

- how looks your hardware setup? - 2 transistors at portc with pull up works at best. nod good because i get different chars... when i only take pullups instead the transisitors, after connect the keyboard it wouldn't be initialized.

Just a pair of 4K7 pullup resistors on clock and data. The pins on my pic are set to be inputs (high impedence) unless I'm transmitting.

- what are you doing at the booting from the pc?

My project doesn't so far parse all of the boot communication which takes place, because it's only used after Windows has totally started.

I'd started to send copies of the incoming data out to a terminal program so I could see what was being said, but didn't spend much time there due to other projects.

However, one of the documents mentioned earlier in this thread has a fairly detailed description of the commands and responses that will be flying around on a properly configured system.

Sorry I can't help much more.

John

[ultiblade]

I'm trying to simulate (emulate) a ps/2 keyboard from a pic to laptop's ps/2 port. The PIC (12F509) needs to send a few keystrokes to the laptop.

Using a part of JEC's code i got it working, but the output (e.g. what i see on my notepad on my laptop screen does not look like the characters i should be seeing, when i look at various scan code tables.

What am i doing wrong ?

Here's the code :

INCLUDE "modedefs.bas"
DEFINE SHIFT_PAUSEUS 50

'==== Andere test ! ============================================================
parity      var word
sendthis    vaR word
kbddata     var GPIO.0
kbdclk      var GPIO.1   

start:
high kbddata
high kbdclk           
 
pause 500

sendthis = %11010110 'sending this results in a "y" on screen
gosub calsub

sendthis = %11110000 'This should be 0xF0 the "release code"
gosub calsub
sendthis = %11010110 'For release code
gosub calsub
goto start          


calsub

parity = not(sendthis.0 ^^ sendthis.1 ^^ sendthis.2 ^^ sendthis.3 ^^ sendthis.4 ^^ sendthis.5 ^^ sendthis.6 ^^ sendthis.7)
    
sendthis = sendthis << 1 'move over to insert start bit

sendthis.0 = 1 'start bit 'In JEC's code this was a 0, but that did'nt work
                 
sendthis.9 = parity

sendthis.10 = 0 'stop bit 'In JEC's code this was a 1, but that did'nt work

shiftout kbddata,kbdclk,4,[sendthis\11]

return

goto start

The "y" i got when i was experimenting, other thing i saw was :

11000111 = 3
11000110 = DEL
00010010 = o
11010110 = y
00110010 = F4
11011110 = NUM-LOCK
11110110 = PAGE-UP

What is wrong ???

Best Regards, UB

[skimask]

INCLUDE "modedefs.bas"
DEFINE SHIFT_PAUSEUS 50
parity var word:sendthis var word:kbddata var GPIO.0:kbdclk var GPIO.1
start:
high kbddata:high kbdclk:pause 500:sendthis=$d6:gosub calsub:sendthis=$f0
gosub calsub:sendthis=$d6:gosub calsub:goto start          

calsub:    <---ADD COLON HERE

parity=not(sendthis.0^^sendthis.1^^sendthis.2^^sendthis.3^^sendthis.4^^sendthis.5^^sendthis.6^^sendthis.7)
sendthis=sendthis<<1:sendthis.0=1:sendthis.9=parity:sendthis.10=0:shiftout kbddata,kbdclk,4,[sendthis\11]:return
goto start

[mister_e]

what happen if your change NOT by ~ ?

[skimask]

what happen if your change NOT by ~ ?

Agh! Missed that one! And it was right below my comment!