Keyboard Encoder

[mpm32]

I have a project where I need to wire 4 buttons to control Page Down, Page Up, Home and End.

I don't really want to buy an I-Pac to do this.  I cracked open a couple of keyboards but they both had membrane switches that can't be soldered to.

It has to be a USB keyboard too.

Any ideas?

Can I just solder to the chip once I find the correct pins?

[RandyT]

I have a project where I need to wire 4 buttons to control Page Down, Page Up, Home and End.

I don't really want to buy an I-Pac to do this.  I cracked open a couple of keyboards but they both had membrane switches that can't be soldered to.

It has to be a USB keyboard too.

Any ideas?

Can I just solder to the chip once I find the correct pins?

For just a few keys, there's no problem doing this.  But you would not necessarily be looking for a chip to solder to, rather some lands on the PCB.  Most keyboards nowadays don't have a normal chip with pins, rather the tiny core of a chip attached directly  to a PCB and covered in a drop of epoxy.  So, from the mylar, you will need to trace back the connections for the keys you need, which will show you the fingers on the PCB you will need to attach wires to.  They may be covered in a conductive black material that will need to be scraped off before you attempt to solder to the fingers.

RandyT

[tikbalang]

the black conductive material can be removed with a hard pencil eraser. this also cleans the contacts making it ready for soldering. for keys, i suggest using the "home" keys on the keyboard (a,s,d,f and j,k,l,;). these are the usual keys that can be pressed at the same time. there are tools on the download section for this.