my keyboard solution for a cockpit

Hi,

In my search through ebay, I came across a Bendix datalink panel and that made me think.
It has all 26 keys, arrows, space, shift,....so could something be done to interface this into my cockpit and get rid of the keyboard?
What the heck, it only costed me 30 dollars so I went for it.

https://lh6.googleusercontent.com/-B...o/s800/003.JPG

One week later I received the item and got started unscrewing the box, removing all unnecessary hardware, untill I got to the keypad itself.
To my great surprise it was wired as a 'simple' keyboard matrix. Wiring matrixes was new to me, so a lot of trial and error was involved.
But after half a day of trying I got the whole keypad working through a Pokeys card!

https://lh5.googleusercontent.com/-i...U/s800/001.JPG

From time to time this item pops up on ebay, usually sold by 'swift46', which I can highly recommend (it takes 7 days to get it from the USA to Belgium)
If you're interested, you can find the wiring scheme below:

The flat ribbon cable that comes out of the panel needs to be cut and then shrink extension wire to it to hook it up with any interface device (Pokeys I recommend as it requires no diodes for matrixes).

https://lh6.googleusercontent.com/-5...s/s800/002.JPG

The ribbon consists of 20 wires but you don't need them all as some are for backlighting.
I'll number the cables 1-20, starting left to right

cable1=column G
cable2=row1
cable3=column F
cable4=row 2
cable5=column E
cable6=
cable7=
cable8=column D
cable9=
cable10=
cable11=
cable12=row 4
cable13=
cable14=
cable15=row 5
cable16=row 3
cable17=column A
cable18=column B
cable19=
cable20=column C

I use 5v for backlighting and that is sufficient. After an hour on it produces quiet some heat actually.
I did not register which remaining cables are combined but the bulbs used do not have polarity so you will have to try several combination and see which ones give you the best backlighting results. I ended up with a nicely lit up panel :D

https://lh3.googleusercontent.com/-e...8/s800/007.JPG

Hope this helps someone