DS Brut is a slot 1 DS card with a number of interface pins (UART TX/RX pins, plus 5 general purpose pins) It can be used for things like hardware sensors (Light, temperature or maybe accelerometers) or communicating with external devices. But more interesting is the possibility to send and receive MIDI or perhaps even synchronize DS music software with LSDj or Nanoloop by emulating the original Gameboy serial protocol. Neither is possible yet, but the DS Brut is completely open source, including the firmware for the onboard Atmega 168 microcontroller, which means that it can be implemented with a little effort.
So, what are the pros and cons with this device? The big pro is the price tag - 26 euros for a DS hardware interface that can do virtually anything is really great. (There’s also a UART only version for 19 euros.)
The only real con I can see with this device is that it has no onboard memory. This means that unless you have a custom firmware and a slot 2 backup device, you’ll have to do cartridge swapping to use DS Brut. I imagine that in the long run, the cartridge swapping will wear out the interface pins and cause loose contacts. I’m not asking for the DS Brut to be a replacement for my M3 card, but for the next revision I’d like to see a few kilobytes of memory that can hold a small bootstrap to start code from a GBA cart or elsewhere. A couple of unused pins on the microcontroller could easily have been connected to the relevant pins on the Slot 1 bus to keep the door open for adding a bootstrap in a future revision of the firmware.
Apart from this minor remark, DS Brut is a promising piece of hardware that opens up many interesting possibilities, including sending and receiving true MIDI.
Link: DS Brut