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Support Forum » PS2 Keyboard Project not working

February 20, 2013
by Johnny544
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I'm a newbie who has successfully completed 4 projects. I decided to try the PS2 keyboard project, but I can't get it to work. When I run it, all I get is a repeating symbol on the LCD (about 1 per second). When I type, nothing happens.

Just for fun I tried swapping the data and clock lines, and I got a repeating question mark.

I'm not sure this is pertinent, but I bought a USB/PS2 combo keyboard. It came with a USB connector and a USB-to-PS2 adapter. I was able to identify the four wires as per the instructions by plugging in the adapter.

Thanks in advance for your help,


February 21, 2013
by Johnny544
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I just wanted to add-- I found a fifth wire-- bare copper with no insulation-- that is attached to the shield of the PS2 connector. Do I need to connect this to anything?

Thanks again.

February 21, 2013
by Ralphxyz
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Generally a bare wire is some sort of ground, in this case it might be a chassis ground and possible not needed but changes are it will not hurt to connect it to ground.

You might check first with a continuity tester to make sure there will not be any shorts.


February 22, 2013
by Johnny544
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Thanks Ralph. I'll hook it up to ground and see if that helps.

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