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|Last update: 2016 05 13|
|gratefulfrog *on* gmail|
ArduGuitar Home Page
The Ardu2 circuit is has come along way since last I posted. I now have a fully operational circuit on a PCB, and a mock-up HMI!
And don't forget to read the doc!
and to check out the code in the github repo
The ArduStomp is GO! Check out the Video Fly-by!
The ArduGuitar Presentation Video (30 mins)
from the amazing 30C3 event! Check it out!
|The ArduGuitar in 3 or maybe 4 slides|
|Check out the write-up on HackADay.|
|The ArduStomp: a StompBox control (strawman), check out the Video!|
|The ArduGuitar available for Android!|
Look ma: no pots to turn, no buttons to push!
After breaking an ACL in a tiny ski accident last winter, and depriving myself of the best ski season in the Alps in 15 years, I had nothing much to do but work on my ArduGuitar project which some may remember consisted of replacing the antique electromechanical controls of an electric guitar by a remote control on an Android phone connected by bluetooth to the guitar.
Well, version one dot one is now done! (version one includes automated switching of presets, thus enabling on board effects by just varying the pickup selection, and/or the volume/tone settings, version 1.1 adds a bluetooth stomp box and some better error correction code)
Although my electronics knowledge dates back to my junior year of high school in 1974, knowing three of the greatest software designers in the world, GIYF.com, the hackerspace community, GNU and open source were enough to make this a huge success!
Check out a few pictures at the ArduGuitar Home Page , or all the gory details on my project notes. The code is available in my github repo.
So what did I do?
First, I analyzed the circuitry of an old Ibanez RG140 guitar which dated back to 1980. Don't worry, that's not old for electric guitars, in fact people pay more to get even older junk - as if any technology was better in the 1950s than it is today? What kind of person would believe that? So, I looked inside this old guitar and saw 2 switches, 2 potentiometers and a capacitor. All poorly soldered together in Asia a long time ago. I should mention that my RC model building has taught me how to solder properly. So only a few components, how hard could that be to "modernize"?
Well, according to my music industry engineer friends, it was both impossible and stupid. That cooled me down about a year ago. Then, being someone who never gives up (which can be both good and bad), I continued thinking about it and came up with a sub-optimal idea for a circuit that I thought would be ok, if not equivalent to the original. But even that was more than my ancient electronics knowledge would allow me, so I started seeking help in the hackerspace community to which I had been introduced by Mitch Altman of "TV-B-Gone" and Noisebridge fame - I met him at the Brussels TEDx.
The hackers had lots of ideas, and one in particular made all the difference. The real issue was how to use a digital circuit to control an analog signal. Well, there is an easy way: use light! A LED shining on a Light-Dependent-Resistor appeared on the horizon. Putting two of these together could be used to make a digitally controlled analog pot.
So, I have a bunch of LED-LDRS (called Vactrols) connected to an Arduino, connected to an Sparkfun BlueSMIRF Silver bluetooth transceiver all in the guitar. (I had first used an 8€ JY-MCU bluetooth mdoules, but after spends weeks trying to reduce the noise it made, finally learned fromt the INCREDIBLY good support at Roving Networks and at SparkFun that the lack of shielding and lack of certification of the JY-MCU really meant that it was noisy junk...)
On my "smart" (or more appropriately "emerging intelligence") Google Nexus 4 phone (that I had to buy in France, because Google won't sell them in Belgium, or even let you look at the webpage from a Belgian IP-address), I wrote an App that has preset configs, plus offers all the possible settings, and even more than on the original guitar. The presets can be updated and saved to the phone's memory. The phone communicates via bluetooth with the guitar and can be several meters from the guitar (I've tested it up to 5 meters away). But since I need the control to play the guitar, I choose to keep the phone above the guitar held in place with velcro. Later, I ran the app on my Nexus 7 tablet as well!
It was a huge learning experience, but during the voyage, I got a bunch of ideas for a next version, which will be even better!
But what exactly is the ArduGuitar?"