Behold the Misa Digital Guitar:
The Misa runs Gentoo Linux on an AMD Geode processor, using the Linux kernel version 2.6.31. It sports MIDI and Ethernet ports for connectivity.
I had the chance to ask Michael some questions about the guitar and his preferred choice of operating system:
Why Gentoo?
Since the guitar is an embedded system, I needed a really minimal distribution that would boot fast and had a small footprint. After investigating Linux From Scratch, I realised I did not have the time to invest in building a complete system. I was told that the minimal install of Gentoo is like Linux From Scratch with a package manager. I probably made you cringe with that simplistic analogy but essentially it was right for me. Once I had the install up it took me no time to recompile the kernel and streamline it as much as possible. I'm not a Linux expert though, so I reckon someone else could shrink it even more.
Yes, there are other solutions out there but they are surprisingly inaccessable. And the "live-CD" style distributions do not allow you to change the actual workings of the system. I figured it was best if I just used Gentoo because I have full control.
What were the two biggest challenges in crafting this instrument?
I would say the two biggest challenges are: 1) manufacturing and tooling the actual parts; and 2) sourcing components.
When you are a lone developer with no company, trying to keep the idea "secret", no one wants to cooperate with you. For example if you need a particular electrical like a screen, ordering "one" of something is surprisingly difficult - and you can expect it in 4 to 6 weeks - really slow! And then when you get it, you realise it is not suitable, so you have to repeat the process. The only exception is a website called Digikey, which will have the parts at my doorstep in 1 week guaranteed. But they don't have everything.
Working with Gentoo was a breeze, the Linux community in general is extremely helpful.
What can you tell us about the hardware?
There is no signal processing, it outputs digital signals via a MIDI connection. I had toyed with having an onboard sound generator but ultimately you limit the sound possibilities. By using MIDI, you are guaranteed support with practically every sequencer, synthesizer etc on the market - it is a standard that has been around for over 20 years.
[The touchpad] is a 5 wire resistive touch sensor. These are the most durable screens available on the market. The LCD behind it is OEM and ordered from China.
What changes to Gentoo (as a distribution) would make it easier for you to run it on the guitar?
I thought Gentoo was a breeze to work with. And can I just say, the Gentoo x86 install handbook? BRILLIANT. I used it so much that I think I actually know it off by heart now.
What's in store for the future?
I'd just like to see these instruments hit TV :)
Thanks for your time, Michael, and for crafting such a unique instrument! Be sure to watch a demonstration video of the Misa Guitar in action.
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