Another part of my forthcoming interactive tv installation is the hardware infrared to midi box I built for interfacing old tv remotes with max and jitter. This was a pretty simple project based around the now ubiquitous Arduino microcontroller and a rather handy i.r. receiver chip I picked up for next to nothing from Sparkfun.
The box plugs in to my computer using USB and a max patch takes care of churning out the midi to whatever application I fancy. As well as using it for my installation I use it for controlling Ableton while standing a.f.k practicing bass. I included a hardware reset switch on the top which I hardly ever use since the latest Arduino’s support software reset when loading firmware and seem much happier with Max’s port object.
I stuck on two LEDs to give some user feedback, green for power and red for code received. I initially tried to write my own firmware for decoding the signals but after googling around a bit I came across this guy’s code which worked much better than my own attempts and saved me about three weeks work. Basically the box just chucks out a unique hex code for any button on any remote that’s sufficiently close to the RC5 Philips standard which seems to be most of the ones in my house. Max takes care of assigning each code/button to a MIDI message, like note, program change or continous controller but I might in the future go back and shift this functionality from Max into the hardware. When I’m using it with Ableton I just route the midi back from Max to Live using midiYoke.
Looking inside you can see there’s not much going on here, just the Vishay TSOP85 receiver and the circuitry for the LEDs and reset switch (this is on the flip side of the vero board but it’s just some pull down resistors). The nice thing about the receiver was it came with the neccessary circuitry integrated so all I had to do was wire it up to the power and one of the digital inputs on the Arduino. I’ve recently become obsessed with socketing things so I can pull them out and swap/replace them as I see fit so I used a few of these yummy modular connectors from Maplin. That’s where I got hold of the frosted blue enclosure which lets through the i.r. signal unimpeded as well as looking quite shhhexy (as much as a blue see through box can).
That pretty much covers it. I’m pretty pleased with it as it is, the whole thing only cost about £30 and took not too long to build. In the future I’ll post up the Max patch, circuit diagram and a video showing it’s integration with Ableton. Changing scene with the channel change and controlling volume, stop, start, record, etc by remote is really quite handy for me as I play double bass and constantly putting it down just to stop/start is a pain in the arse.