DSP + Arduino
Published: 30 Apr 2013
- arduino
- electronics
- music
Note
This is an old post or draft which was migrated from my old blog. It may have broken links,
and it definitely has questionable opinions. Consume at your own risk.
Amanda Ghassaei, who has this amazing project I just found out about, also has a great Instructable for doing DSP with Arduino. A few hours and one blown op-amp later, I was able to get my Arduino to pickup my bass playing. It samples around 38.5 kHz, but I only had it send serial data back every 10 ms (a measly 100 Hz). Still, I was able to generate this graph with the data. You can see the clipping where I cranked it up to test the peak indicator LED.
The atmega328 has 32Kb flash memory. If I used half of that for a delay line, 16,000 samples / 38500 samples/sec = .42 second delay. I could get a longer delay by using external flash (e.g. SD card), but I worry that the read/write time would be low. It will be interesting to apply some of the concepts from class to actual signals. What does a 50-point averager do to my tone? (answer: probably reverb)
There's not a lot I can do with this now, since I can't hear the results of any processing yet. I just ordered a DAC0808 8-bit digital-analog converter. (The new DUE has two built-in DAC outputs, as well as PWM, although it still isn't an ideal platform for DSP). Eventually, I would like to get an FFT algorithm running and make a tuner. That will probably have to wait until after finals, though.
EDIT: Just found out about wki.pe/Resistor_ladder s.
