Rocksmith, if you haven’t heard of it, is a video game that helps you learn to play the guitar, or bass guitar in “GearWalker’s” case. Think Guitar Hero, except with an actual guitar. Although this is quite an interesting concept (and in some ways makes more sense than ‘Hero), it requires a Rocksmith Real Tone USB cable. Most of the time, this wouldn’t be a problem, but if you buy a digital copy online, you have to also order a cable and wait for it.
Or you can simply make your own. For this, a readily-available USB sound interface was used. Although the wiring isn’t trivial, and requires a certain amount of coordination, the real challenge is getting the program to recognize it as the “genuine” Rocksmith cable. The game verifies that you have the correct device ID, which an ordinary sound interface doesn’t have.
This problem was circumvented by programming an EEPROM chip to impersonate the genuine cable. The USB interface used is set up to be programmed this way, so all that was needed was to program the chip appropriately, then wire it into the USB hardware. An Arduino was used to do the programming, and a sketch is provided.
The video below shows the end results of this experiment. Looks like it’s working well, although I’m not sure if it’ll be able to handle “Monkey Wrench” on Expert. Or whatever the hardest song is. It’s been a while since I’ve played a guitar video game.