Taiko Synth - Phase 7 - Basic Improvements

The volume is now proportional to the hit - although I do need to scale it for better dynamic range. Initially I did the scaling like I would in any software application:

outputValue = inputValue * maxOutput / maxInput

The problem is that Arduino only deals with 16 bit integer math. Anything over 32767 is a negative number. By multiplying first, it went over that value so I was seeing negative volume values when I hit the drum hard. Since maxOutput and maxInput are constants with a ratio of about 5, I re-wrote the formula as follows:

outputValue = inputValue / 5

More work needs to be done on scaling; the detection threshold needs to be lower, a peak indicator LED is needed, and I want to be able to use the nunchuck to adjust the sensitivity. The nunchuck is running out of controls, so I'll try to use the accelerometers.


I'm now running the synthesizer software on an HP 1000 mini running Ubuntu 10.04 LTS off of a bootable flash drive.The latency isn't as bad as before. The little netbook works pretty well. I read that there's a low-latency Linux kernel, so I may try that for fun some day.

I changed the synthesizer software is to FluidSynth (http://sourceforge.net/projects/fluidsynth/). FluidSynth needs a soundfont. It can use the General MIDI instruments which include Taiko (channel 117) and a bird (channel 123 - not so useful, but fun).

Here's where I got the sound font: http://packages.debian.org/search?keywords=fluid-soundfont-gm

Once installed, here's how to start everything.

./ttymidi -s /dev/ttyUSB0&
aconnect -i
aconnect -o
aconnect 129:0 a28:0
fluidsynth -c0 -r0 -r22050 -l -a alsa -o audio.alsa.device=plughw:0 FluidR3_GM.sf2

If you are troubleshooting, there's a -v parameter for verbose, that's helpful.



I installed Jack, a GUI device connector, and experimented with that, but I think it's easier to use Aconnect.

Here's a demo of the results: