madscijr Posted January 3, 2009 Report Share Posted January 3, 2009 I found a thread on here that was a couple of years old (Topic: pitch to midi thru ain?, Date: 2006-10-30 at 16:55) and was wondering if anyone has seen any projects to convert a live mono audio signal (ie vocal mic or single string of an electric guitar) to MIDI using BASIC Stamp 2 or PICAXE? Thanks Quote Link to comment Share on other sites More sharing options...
stryd_one Posted January 4, 2009 Report Share Posted January 4, 2009 welcome aboard madsci :)There are lots of DIY electronics/music geeks around here, so hopefully you will find someone who has also used a BS or PICAxe. In the meantime, is there a specific reason you're considering those two platforms? Perhaps MBHP/MIOS would be a more appropriate solution? You would be working on a platform specifically designed for use as a midi controller, which could make the task quite a bit more simple...Good luck! Quote Link to comment Share on other sites More sharing options...
madscijr Posted June 15, 2009 Author Report Share Posted June 15, 2009 Sure, because I already have BS2 and PICAXE programmers and software and am familiar with their capabilities. Every time you have to change to a new platform it takes time & energy which I have to use sparingly... The PICAXE is probably going to be my platform of choice because they're inexpensive and common and capable. Hope this helps...>In the meantime, is there a specific reason you're considering those two platforms? >Perhaps MBHP/MIOS would be a more appropriate solution? Quote Link to comment Share on other sites More sharing options...
lylehaze Posted June 15, 2009 Report Share Posted June 15, 2009 I can offer a few thoughts, but I do not have a completed project to show off..I have begun a similar project, but it's just one of about five open projects I have going on, so there's no telling when or if I'll finish it.As I began the project, there were a few tradeoffs to consider..The math for converting period to frequency, then frequency to note number, requires some higher math functions. I usually try to avoid this kind of stuff, but it leads to the first tradeoff: If you just want to find the closest note, you can use a lookup table to avoid the math.. that's the easy option. You can also shift the period left and right for octave changes.. so all that is good, as long as you don't need to also calculate the "pitch bend" values to cover the differences.Next possible simplification: If you're only watching for the period of the incoming audio, you don't even need to use an analog input. A simple comparator will output a digital signal that you can use to calculate the period of the incoming audio wave. You can also use A/D conversions and just watch the most significant bit. I would suggest basing your math on the FULL wave, not just a half-wave, to eliminate any errors from offset bias.Finally, your choice of platform. I'm guessing that any of the suggestions made will work, some better than others. Of course you will find people here are biased towards using MIOS and the MIDIBox.[EDIT] I know nothing of the picaxe, but there seems to be a lot of BS in the chat forums. ;-)Starting off with just using a lookup table to determine the closest note would be a great start. How far you go from there is up to desire and determination.Have Fun,LyleHaze Quote Link to comment Share on other sites More sharing options...
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