Bullion Test

GBA flashcart

5.25 LED Matrix

Keyboard Advance

Tic Tac Toe




Robot competitions


Keyboard Advance

17 Mar 2004 - GBA SP

I have now tested this on a GBA SP, and it works just the way it should.

21 Nov 2003 - ZXAdvance & GBA SP

Rumor has it there is support for this keyboard in the next (current?) release of ZXAdvance, the Spectrum emulator for GBA. Me, I'am waiting for someone to write a C64 emulator for GBA so I can play some Last Ninja. :)
alepus reports some odd keyboard behavior on his GBA SP. Aparantly the "Wait a second" line never goes away unless he presses the WWW or E-Mail key on the keyboard. I'am not sure if this is a SP problem, and I don't have a SP myself. If someone else experiences the same thing, please drop me a line.

16 Mar 2003 - Tutorial thieves

-Updated- Since the people at completely ignored my requests that they remove the copy of my tutorial from their website, I decided to contact their hosting company. Just a few days later the copy was removed from their website.

18 Nov 2002 - Software update: Full font

The font is now updated to include all multilingual chars. (like ...)
Thanks to BigRedPmp for his work making the font.
Here's the program, have fun!

30 Oct 2002 - More software updates

Minor bugfix, code cleanup, added keyboard detection messages.
Download it here

29 Oct 2002 - Software update

I've updated the test program, now it handles all keys except the top row function keys. It also features a caps lock feature, use shift+space to toggle caps lock. Using the shift key with any other key will return the symbol printed above the key.
The multilingual chars (ascii codes above 127) are currently not implemented in the font I use, if anyone have a full ASCII table 8x8 pixel font suitable for GBA then please mail it to me and I'll include it.
Anyway, here's the code, enjoy!

28 Oct 2002 - Page started

The Gameboy Advance is a nice unit with great video and audio output capabilities. However, the input capabilities are restricted to only a bunch of buttons, that might be enough for games, but if you ever try to make something more serious with the GBA you quickly realize that more input capabilites are needed.
So, how about adding a keyboard to the GBA?
Normal PC keyboards are out of the question, but check out this cute little keyboard from ericsson:

Model: Ericsson Chatboard CHA-01, normally intended for use with cellphones.
Price: 29SEK + 50SEK S&H, that's dirt cheap in international currency (about 3USD + shipping)

It's small, it's cheap, it's perfect!
First, you need a GBC or GBA link cable, and make sure that pin 1,2,3 and 6 are present! Many GBA link cables are made without pin 1 (Vcc) present.
You can either open up your chatboard, desolder the connector, and then solder the wires to the circuit board, or you can solder the wires directly to the chatboard connector. That way you don't have to open it. Connect the chatboard to your GBA link port according to this diagram:

GBA ----------- Chatboard
2 --------------- 4 (Chatboard serial in)
3 -------[R]----- 2 (Chatboard serial out)
6 --------------- 3 (GND)
1 --------------- 1 and 5 (Vcc)
1kohm is a suitable value for the resistor R, but you can really use anything between 470ohm - 10kohm.
Both pin 1 and 5 on the chatboard must be connected to pin 1 on the GBA link port.

Look! it's alive !
Download a simple test program here (beta) if you want to give it a try.
Due to how the keyboard works you have to push the SMS button and then wait a second before you can type anything.
Not every key works right now, but I'am working on it.

Of course, everything here is provided "as is", and I do not guarantee that the information on this page is correct, if you kill your GBA due to incorrect information on this page, then that's your problem, not mine.

(c) 2002 Timmy Brolin 'AmPz'