DaveyBot

[Len17]

DaveyBot
A computer that plays Guitar Hero and Rock Band

Update (May 10): Software is now available for download. See below. It still needs work, but it gets 96% playing "Painkiller" on Expert.

Overview

I’m trying to hook up my computer to a Guitar Hero controller, and write software to play Rock Band and Guitar Hero. People have asked me why, but I don't think I have to explain it to you guys.

I’m not the first to make a Guitar Hero ‘bot. Here's one and here's another. I’m a software guy and I already have a computer that handles video input (to record TV shows), so I’m doing most of the work in software. The software should work with different games. (I have Rock Band, Rock Band 2 and Guitar Hero World Tour.)

The general idea is:

1. The computer receives the game video from the Xbox 360.
2. Software on the computer analyzes the video to figure out when to play the notes.
3. The software sends commands via USB to an interface module in the Guitar Hero controller. (This is where the Arduino comes in.)
4. The module in the guitar simulates the button presses to play the notes.

DaveyBot is named after a fictional guitar hero.

[Len17]

Software

The DaveyBot software is written in C#. It uses DirectShow to capture the video input (via the DirectShowNet C# library). Each video frame is analyzed to see if a note is approaching the strike line. If so, DaveyBot sends a command out through a comm port, to tell the guitar to play a note.

Here’s a shot of the DaveyBot software in action with Rock Band 2:



The coloured blocks overlaid on the image and above it show the notes that are detected and played. You can see that the image is quite blurry. It’s a challenge to get the software to accurately identify the notes. You may also notice that DaveyBot is losing the game. That’s because it’s not hooked up to a guitar yet!

Another challenge was the DirectShow API for video capture (part of Windows DirectX). I think that API was designed by a Sudoku fanatic who didn’t want anyone else to use it. I figured out how to navigate the maze corresponding to my TV tuner card, but I’m not confident that the software would work on a computer with different video capture hardware.

So far I’ve been using Rock Band 2 but I should be able to tweak the software to play Guitar Hero as well. Some of the specialized features won’t work (solo buttons and slider bar) but I hope to add support for overdrive/star power.

[Len17]

Arduino

To interpret the commands from the computer and simulate pressing the buttons, I’m using an Arduino microcontroller embedded in the guitar. Actually I’m using a Boarduino, because it’s small enough to fit in the guitar, it’s powered by the USB connection from the computer, and its pinout fits nicely on a prototyping board.

The Arduino is connected to the computer via USB, but under Windows it appears as a serial comm port. The commands sent from the computer are each a single byte, with each bit representing the on/off state of one of the switches (fret buttons, strum bar, whammy bar, tilt switch).

The software running on the Arduino is simple. When it receives a command byte from the computer, it turns the appropriate output pins on or off. The strum bar is handled specially. It’s turned on momentarily, then off again after a brief time. The whammy bar also needs special handling, because it has to be moved continually, but I haven’t implemented that yet.

Here’s a video of the Boarduino in action, receiving commands from the computer and driving a set of LEDs in lieu of the guitar switches.

[Len17]

Hardware Interface

Besides the Boarduino, the interface module in the guitar also has a set of opto-isolators, to keep the computer and Boarduino electrically isolated from the guitar controller’s circuitry. I found a pair of quad optocoupler chips (ILQ1) that should do the trick nicely.

Here’s my schematic for the interface board:



Update: I had to change the wiring. Originally it was based on someone else's hookup for a Wii controller, but apparently the switches are wired differently in the Xbox version - can't just hook up the outputs using a common ground.

The next step is to assemble the interface board and wire it into the guitar. My current stumbling block is finding a USB socket. If I’d been thinking ahead when I assembled the Boarduino, I would have put its USB socket on a short length of cable instead of soldering it to the board, so I could mount it in a hole in the side of the guitar. I also need to hook up a reset button because the Boarduino doesn’t always start running its program when I plug it into the computer.

When I’m all done, the guitar controller should function normally unless the USB cable is plugged in.

[adafruit]

sweeeet. please keep posting up your progress!

[Len17]

Oops, what did it say on that sticker?

[adafruit]

nice multitool you have there

[Len17]

nice multitool you have there

I made sure it was in the picture. It usually lives on a keyring next to a USB thumb drive - everything I need for hardware & software hacking.

[Len17]

Useful side-effect of this hacking project: I was able to fix my niece's Rock Band controller the other day. (Using my adafruit bomb defuser, of course.)

[Len17]

Here's the first full test of DaveyBot:


And here's the result:


I can't believe it worked the first time. Yay!

Next I have to mount the interface board permanently in the guitar, and then there's lots more work to do on the software.

[Len17]

Just received this email from a friend:

you've finally gone completely mad

[Len17]

Here are a couple of pictures of the finished hardware mod.

(Click on this picture to see an annotated version.)

[adafruit]

y0w!

[Len17]

Download

Windows program & source code, Arduino source code, hardware schematic.

Download here