PS2 Mouse and Keyboard connections not working on Propstick ?

T&E Engineer

I have wired up 2 PS2 cables as indicated in the Propeller Demo Board schematic using the 100 ohm and 10K ohm resistors as drawn. However, I can not get any of the mouse or keyboard related programs to work (no activity on either). I have done a full continuity and ohm check on all the connections and everything checks out well. All I see on power up is the Keyboard LED's for num lock, caps lock and scroll lock turn on briefly as they should and then go off. This tells me that power is connected correctly. I am using a brand new Radio Shack PS2 keyboard and new Radio Shack PS2 mouse. I·unsoldered a new USB to PS2 cable adapter ($22) as PS2 cables are not easy to find·cheaply. ·All the connections check out from the end of the PS2 connector to the P24 - P26 connections including the 100 and 10K ohm checks.

Where else should I look for a problem or is there a problem with the schematic or something?

Thanks for your help.

·

Mike Green

Make sure the programs you are using have the correct pin numbers. Some early keyboard/mouse demos had the pin numbers used in an earlier version of the demo board.

T&E Engineer

Thanks Mike. I knew it had to be something simply like that. I will check the programs later and test it out tonight. Do you know of any mouse / keyboard programs that I can look at with the same pins as the Demo board? I did also notice that a couple of the ones I saw had errors in them too and never loaded into the EEPROM.

T&E Engineer

This is similar to another post I have.

I have both the keyboard and mouse working now. The Schematic is a little misleading and possibly wrong.

I had to swap the DATA and CLOCK wires on both the mouse and keyboard. Now it works great. Also make sure the 10K resistors are going to 3.3v from the propeller chip - not 5v.

Thanks.

Mike Green

The keyboard and mouse pins were changed around between revision A and revision C of the demo board (revision C is what is sold by Parallax). Make sure the schematic is the revision C one.

T&E Engineer

Yes. I downloaded rev C from the Parallax website. It does appear that the DATA lines are where the CLOCK lines are. If I was looking at the opposite downside insertion view then the +5v and ground lines would also be swapped and this is not the case. I can take the PS2 end connector and follow the schematic pin for pin to the chip and it does appear that the DATA and CLOCK lines are reversed.