git clone http://www.bamsoftware.com/git/vga.git
Palantir was giving some kind of promotional speech at school. Because Palantir are a bunch of motherfuckers, I wanted to try to ruin it. I had the idea of putting a VGA-generating device inline with the projector input cable to show a custom message instead of what the presenter wanted.
Ideally such a dongle would accept VGA input, so that it could know when it had been connected to the presenter’s computer. Even better would be if it could pass VGA unmodified from its input to its output until about five minutes after the presentation is scheduled to start, and then start substituting its own message. I didn’t know how to do those things, so I just gave it a dummy input not connected to anything, and an output that showed a phony “maintenance cycle” message until the presentation is supposed to start. Then it starts a looping message.
I used an Arduino Uno and the Gameduino shield, bought from SparkFun. There’s no clock that works while the device is powered off, so you have to program the device with the time that you plan to turn it on, and then a library calculates the time by counting cycles or something.
Sadly, I didn’t get to deploy this. I got early to the presentation room, but there was a class there right up until the start of the presentation, and the presenter was there really early so I didn't have access to the VGA cable.