16/03/2023

Homebrew keyboard

 No keyboard ? Make it yourself !

I had an old project for a numeric keyboard for an IC-706, collecting dust on the shelf.
It was built after a QST article from December 1999, by John Hansen, W2FS.

John had used a special keypad/project box from Radio Shack, that had 3 columns and 5 rows.
All I had was a keyboard with 5 columns and only 4 rows ... hmm, what to do?
Well, I turned that keyboard 90 degrees and used it as such, but that was not very practical.
See picture : for 1 type 1, for 2 type 4 , for 3 type 7, and so on, hi .... but it worked.

I never built it into a box because of that awkward keypad, and the project got forgotten.

°°°

Recently I thought, maybe this keypad also works on my newer IC-7300 ?
And it did !
All it took was entering **94 (the address of the 7300).

Of course, the IC-7300 has an on-screen touchpad to enter frequencies, but this keypad works quicker, it needs less key presses, and it automatically selects the corresponding MODE, based on the bandplan (see further).
And there is no need to block the screen on the transceiver with the touch keyboard.

This time I really needed a fitting keyboard and it had to be in a  box to be useful in the shack.
But wherever I looked (Ali Express, eBay, etc ...), I couldn't find a 3x5 keypad.


SOLUTION : make one from scratch !

In the mean time I also found an interesting website by G4FEV, who made his keypad from an old PC keyboard, which is also nice. See http://g4fev.atspace.com/keypad.htm

More important, he also had another version of the hex file on his website, which uses the European bandplan (with instructions how to change the necessary bytes yourself).
So, I reprogrammed my PIC 16F84 with his file, it works great !

OK, now for my version of a keypad ...
I had a box with some hundred loose pushbuttons, some even with an LED inside, so I used one of those as a "Power ON" indicator.

First I bent two pieces of plastic into a simple cabinet, with a tilted top panel (using a home built plastic heating and bending machine).



Then I made a rectangular cutout for 15 keys, by drilling holes all around the contour, then moving the drill sideways cutting from hole to hole ...


After that I filed the borders until the size was correct, and everything was smooth.

Now came the difficult part : using two-component epoxy, I glued 15 keys toghether into a one-piece keyboard. After the epoxy had set, I soldered some wires to connect rows and columns.



After all the wires were connected, a quick test showed that it worked.
But the front still looked like this ...



Now, how to label the keyboard and get a clean finish ?

My simple solution : I printed the needed symbols on a piece of colored paper, fixed it in the correct position with some Pritt  glue stick. I didn't forget to punch a small hole for the power LED in the lower left corner.



Finally, I covered the whole thing with selfadhesive plastic foil, drilled a hole and mounted the power switch. Done !


The inner works may not look as neat as the outside, but if it works , that's OK with me ;-)


All in all , I think it's a useful addition to the shack, and if I ever use my old IC-706MkIIG, it can easily switch address ... or who knows, I may make another keypad ! 

73,

Luc ON7DQ