Tonefiend Forum

Has anyone played with Arduino microcontrollers for guitar/effects stuff?

We've been using them at work for hardware prototyping (computer input devices and stuff). However I've been given an LeoStick as a Christmas present, and I thought it would be cool to discuss how these things could be used in guitar effects.

This particular unit has 14 digital I/O pins (each pin is either input or output). These could be used for switching, controlling relays, LEDs, or reading the state of switches and buttons. It also has 6 analogue pins. The microcontroller doesn't have enough power to do do any real signal processing, but you could use the analogue pins to do things like read potentiometer values, or maybe use pulse width modulation to control things like the rate and shape of a tremolo effect using the microcontroller.

Anyway, I guess I'm just curious as to whether anyone else is using these things?

I HAVE an Arduino, and I hooked it up and made it blink an LED (just to make sure it knew who was boss around here) but since then it's been sitting around awaiting its opportunity.

The most interesting projects I've seen include a little signal generator for audio testing, and doing an FFT (spectral analysis) in real time. I don't have that much interest in processing digital audio directly with it, but who knows... could happen...

https://www.instructables.com/id/Arduino-Waveform-Generator/

https://www.openmusiclabs.com/2012/08/arduino-fft-get-your-freq-on/

Oh man — I am so interested. I have two Arduinos here that I've been MEANING to explore for, like two years. 🙁

I want more hours in each day, please!

I've been meaning to get an Arduino or Raspberry Pi to play with myself for a while. I've mostly played with Stamp processors which are less powerful but still cool. I designed a Stamp based circuit to control video projectors via their serial port for power, input switching etc. It is a very cheap solution for the university I worked at we also built and sold them to other users generating some income for our classroom technology dept. It has been very popular with people having permanent installs of video projectors. It worked on all projectors except Sonys which are great units but a pain to interface with almost any system available due to their serial port protocols. I also built a similar system to control switching for a couple of bars in town to control the audio system switching for PA, video and paging. You can idiot proof stuff easily with them. The newer generations like the Arduinos and Raspberry PI are much more capable but if I was doing any signal processing I would use some of the new generation DSPs that are very economical, easily programmed and easy to interface. I am helping a buddy that designs speakers to implement a DSP based audio processor for PA speakers. He designed and built some cool 5" drivers with massive magnets that sound great when used with a sub and some tweets. I have also seen some great Arduino based synth and midi controller circuits on the net lately. Sure beats the heck out of the 8 bit cpu systems I started fooling with.

Those are the sort of things I was thinking of doing with a Raspberry Pi. It's a drag that the JACK subsystem is not stable. Is it possible to dump the graphical interface and just run command line stuff to speed it up? Heck I always thought a graphical desktop was a bit heretical on any form of unix but I am an old guy after all. Tho' I will say I liked running Sun Solaris for the chemistry instruments as it let me spend a lot less time holding the hands of PHDs when they were using the instruments they spent a fortune on. I need to look at the Cubie board especially if the real time capabilities of Android have gotten to a useful level.