Ever find yourself in the middle of a Game Boy game and your hand cramps up?  Save that sore wrist for something else because now you can hack the Game Boy Advance to add Rapid Fire for the B button.  [William] has developed a way to do this by creating a simple circuit that generates a square wave on the B button when it is pressed.  To do this hack all that was needed was a short shopping list of:

• A Couple NAND Gate ICs
• 2n2222 NPN Transistor
• 0.1uF ceramic capacitor
• A Switch
• 1M ohm resistor
• Some Thin Wire

After that you’re off to the races as [William] documents how he goes about transforming the Game Boy Advance and includes a ton of great pictures and a schematic.  This operation ends with [William] placing the switch for Rapid Fire excellence next to the Right Bumper where it is inconspicuous and yet easy enough to access.

Via [HackedGadgets]

Tired of messing with the hardware of the Didj you picked up? Now you can use it for gaming on that last road trip of the summer. A Game Boy Advanced emulator has been ported for use on both the Didj and the Explorer. You’ll have to dig up a copy of the original bios for a GBA as well as some ROMs, but the rest seems pretty straight forward. We are still holding out hope for Doom or Quake on the Didj, but this will help us wait a bit longer.

[Thanks Nirvous via Rosincore]

[Steve] wanted to do some ARM development and set his sights on the Game Boy Advance as a development package. In order to get his code onto the device he build an Arduino-based communications cable. It is necessary to have a microcontroller involved because the GBA uses a peculiar 16-bit serial communications protocol. This cable is an adaptation from the 8051-based cable developed by [Matt Evans] several years ago. [Steve's] got it working by porting the 8051 assembler over for the Arduino, but we’d recommend adding a level converter to his hardware setup to step down from the Arduino’s 5v logic to the 3.3v logic the GBA expects.

He didn’t make up a wiring diagram, but in the code comments [Steve's] laid out the connections as follows:

Arduino 8 to GBA SO
Arduino 9 to GBA SI
Arduino 10 to GBA SD
Arduino 11 to GBA SC

That’s it, follow the README in his source code package and you’re on your way to some ARM development.

[Hounjini] was poking around at the Game Boy Advanced bus of his Nintendo DS lite and figured out how to use it to connect an Arduino to the DS. For testing he’s soldered an IDC plug to the cartridge cover pin interface but this only requires four connections. The Arduino can both send and receive data from the DS lite as shown in the example videos after the break. The data access is made possible by making the Arduino look like a controller that the DS is happy to talk to.

[Thanks Christian]

[via Matrixsynth]

Aside from what is demoed in the video, DScratch can record and scratch audio directly from the microphone. It also has the ability to send midi data via the DS’s wifi, which in turn can be used to control external MIDI apps. Dscratch also has NDSMotion support. The DS slot and GBA slot DS Motion accessories contain accelerometers and gyroscopes that generate different effects in DScratch when the DS is shook, tilted, and turned. It’s not required for DScratch to work, but it maximizes the app’s functionality.

If you can’t wait for a full version, you can get the Korg DS-10 cartridge. Instead of emulating a turntable, though, this software emulates a Korg MS-10 synthesizer. It can handle music creation and editing like DScratch, but it cannot do midi controlling via WiFi. For that, try DSMI, an open source software suite we covered back in 2006. It consists of software for the DS that controls and sends midi messages via WiFi to the server software on a computer, which in turn feeds it to any running MIDI software. Neither of these do exactly what DScratch does, but they should keep you busy until the full release.