Midi

General AVR Considerations

There are MIDI libraries out there. I have not had a lot of time to play with this yet. First however, its good to know the capabilities and limitations of what we have to work with.

The TX/RX is a serial protocol that is called UART. Midi uses UART to communicate at 31250 baud. There is apparently a 1% tolerance here. Most folks seem to have success with internal 8mhz clocking.

Many AVRs chips have a built in UART capability already there. ATTINY84 and ATTINY85 do not. You can still communicate with UART, however, keep in mind that many sketches out there might be built on libraries that assume atmega328 or up.

I read somewhere that 2313 has dedicated on board capabilities.

So my overall conclusion is that if you are building something that relies on strong midi capabilities and involves an investment of parts/enclosures and the like, you should consider using something like the atmega.
You can use the external xtal and have more pins for things. Might as well midi out too eh.

There are projects out for that.

Or save a little time and maybe buy a good start http://bleeplabs.com/store/the-rad-fi-system/

Ok...so your gonna give it a shot anyways huh? Lets see what we can learn.

Interface circuits

Midi In

In just about all cases, you will need to use an opto Isolator of some sort. Think of it as a fire wall of sorts.