Guitar Motion Sensor

[Inventor]

Hi folks,

I'm working on a DIY project and at this time I'm asking for advice from the guitarist community about it.  The project is a Guitar Motion Sensor, or GMS, that uses a triple-axis accelerometer chip to sense the gyrations of a guitarist moving about on stage, and control effects in response. 

So for example one could put tremolo on the phi, or vertical angle so that when you tilt the guitar neck up to the sky the LFO of the tremolo speeds up and when you lower it horizontal it slows down or stops.  Then perhaps put your auto-wah effect on the theta, or torso-twisting angle so that you get varying frequency of auto-wah as you sweep the guitar around in a circle.  Sounds cool, eh? 

Also there will be an optional stomp box on another USB interface that controls the software, and that stomp box will have up to four optional foot pedals.  Or that's the plan anyway, I'm open to suggestions on that or really any aspect of the project. 

I'm writing the initial software for the project in a programming language called ChucK that is freeware, and my software will be free as well. 

Well I won't talk your ear off, I'll just close by mentioning that I've created a somewhat blog-ish sort of website to act as the central information point for anyone wanting to DIY their own GMS.  If you're interested in the project, your best starting point would be to give the pages a quick skim-over.  Just reading the headings and looking at the pictures will give you a feel for what the project is about, then you can zoom in and read the sections that interest you.  Also there is free demonstration software that I've coded up that uses the mouse as a pretend GMS so you can try out the concept and see if you like it.  Great, well, the website is here:

http://www.freedomodds.com/music/gms.html

Best wishes and happy guitar DIY to all! 

[zhx]

Sounds interesting. It would be cool to control tremolo by shaking the guitar...

Reminds me of a british tv-show, where a guy built an electric drum set, where the drums were triggered by IR-sensors (or laser beams, I don't remember). He basically played the set by playin "air drums".

[Inventor]

Yeah, I'm into the whole coolness factor of it.  I spent a whole career chasing degrees and being a corporate drone.  Now that I have plenty of time for myself, I want to spend it doing something fun for a change!  I want some famous guitar player or maybe just the neighborhood kid to try it out and say "Wow"!  I was up all night coding the software for it, busy busy busy! 

[demonstar]

Hi folks,

I'm working on a DIY project and at this time I'm asking for advice from the guitarist community about it.  The project is a Guitar Motion Sensor, or GMS, that uses a triple-axis accelerometer chip to sense the gyrations of a guitarist moving about on stage, and control effects in response. 

So for example one could put tremolo on the phi, or vertical angle so that when you tilt the guitar neck up to the sky the LFO of the tremolo speeds up and when you lower it horizontal it slows down or stops.  Then perhaps put your auto-wah effect on the theta, or torso-twisting angle so that you get varying frequency of auto-wah as you sweep the guitar around in a circle.  Sounds cool, eh? 

Also there will be an optional stomp box on another USB interface that controls the software, and that stomp box will have up to four optional foot pedals.  Or that's the plan anyway, I'm open to suggestions on that or really any aspect of the project. 

I'm writing the initial software for the project in a programming language called ChucK that is freeware, and my software will be free as well. 

Well I won't talk your ear off, I'll just close by mentioning that I've created a somewhat blog-ish sort of website to act as the central information point for anyone wanting to DIY their own GMS.  If you're interested in the project, your best starting point would be to give the pages a quick skim-over.  Just reading the headings and looking at the pictures will give you a feel for what the project is about, then you can zoom in and read the sections that interest you.  Also there is free demonstration software that I've coded up that uses the mouse as a pretend GMS so you can try out the concept and see if you like it.  Great, well, the website is here:

http://www.freedomodds.com/music/gms.html

Best wishes and happy guitar DIY to all! 

I'll be interested to see this when it's complete. It's not really the kind of thing that I would use but I could imagine many people being attracted to it. Some of the concepts seem like on the guitar hero console game when the controller is tipped for vibrato. I think for that reason it may appear 'cool' to non-guitarists therefore maybe guitarists will do it to be 'cool'.

Anyway nice to see someone working on something new. All The best with it!

[Inventor]

Thanks!  At the time that I thought this up, I was not aware of the Guitar Hero and Hot Hand products doing similar things, but hey, when an idea's time has come it will emerge in various forms all over the place.  Lately I've been having fun coding the software, it works like a non-dynamic effects box with four stages in series.  Later I'll add the actual control interface once the hardware is designed.  I'll keep you posted...

[Inventor]

Hi folks,

Just a quick message to let you know that I have received the working prototype from England and tested it.  The thing works great!  Now I can set up the software and then play the guitar with effects that vary as I move around!  Ultimarc assures me that they can spin a board fairly quickly, so we should have a commercial product for you to buy at a low price fairly soon.  Great news! 

[mth5044]

I must see this thing in action. Any videos yet?

[carrejans]

Sounds very interesting.
A video would be nice, indeed. 

[Inventor]

I have some audio examples. The last I heard, the British company I am working with was sending the design out for manufacture.  I have contacted them via email asking for status, but no reply has been returned yet.  I hope they didn't drop the project, but even if they did we can still DIY our own with a simple five-wire soldering of two circuit boards.  If all goes well the product should be available soon.  I am picturing my role in this as tapering off and I'm working on follow-up circuits like a Theremin and others.  I'll keep you posted.  Here is an audio example file of me doing wah by wiggling the guitar around: 

http://www.freedomodds.com/music/songs/GMS_example8.mp3

[flo]

Interesting... I would love to use the guitar directly as an interface to control sound characteristics. Please keep us posted on your progress especially when you have a clear DIY project available.
Downside is to need a "translating" computer for it to function. Perhaps a dedicated PIC uController could take its place to make a more portable hardware solution?

[Inventor]

Interesting... I would love to use the guitar directly as an interface to control sound characteristics. Please keep us posted on your progress especially when you have a clear DIY project available.
Downside is to need a "translating" computer for it to function. Perhaps a dedicated PIC uController could take its place to make a more portable hardware solution?

Yes, flo, it is a bit of a downside that you need a computer, plus the USB cable is a possible problem.  The good thing is that having a puter in your setup opens up lots of software options.  For example, one of my programs is a "thunderstorm" with fairly realistic thunder that happens after each note.  It has rain also.  That's not easy to do without a computer.  Plus it is possible to interface the sensor with existing effects software that is popular and very nice.  It is also possible to mount a miniature computer on your guitar if you've got the bucks and can figure out how.  Sony sells a tiny one for example.  Any successful rock gods out there want me to build a digital dream guitar for you?  LOL! 

I agree that a pic-based or solution would be a good compromise, or even just a full-blown analog manipulation of the 3-axis accelerometer's output would be nice.  The possibilities are endless.  if you have further interest in the project, I call your attention to the link at the top of this thread, or you can email me for technical discussion:  inventor-66@comcast.net. 

[carrejans]

Still no video? 

[evilpaul]

Guitar accelerometer FX proof-of-concept using a Wii remote. Spotted on Hack A Day

http://www.youtube.com/watch?v=xmuggHx_H5Y

[Inventor]

Guitar accelerometer FX proof-of-concept using a Wii remote. Spotted on Hack A Day

http://www.youtube.com/watch?v=xmuggHx_H5Y

Excellent!  Thank you so much, evilpaul for posting that video.  You can definitely do this with a WiiMote and that has the advantage of being wireless, if you feel comfy with that instead of a cable.  Sorry to say, i have not heard from the British manufacturer of the GMS hardware for a few weeks.  He *did* say that the board house in India was quite slow, so maybe he's waiting on boards, I will have to email him.  At any rate there is the WiiMote solution and my earlier accelerometer prototype even if the big effort of the GMS proto doesn't pan out.  So that's the status, sad though it is it is out of my hands at the moment.  If anyone really wants it now, you can make a prototype by just soldering about five wires to a socket from a wire harness and you will basically have what I have, or else go with a WiiMote.  I have other software including Wah and a nice thunderstorm effect which I need to post.  Anyone interested, email me and I'll get off my butt and make you happy!  haha!  Cheers and take care. 

[Inventor]

I just heard back from Ultimark in England, they are expecting 5 sample boards on Monday, so things are looking up.  This delay may be inconvenient, but the good thing is that we'll get nice low-priced boards from India.  Cheers! 

[Inventor]

Hi Folks, just tickling this thread to let you know that I received the working prototype a couple of weeks ago and it tests out just fine.  Right now the only delay is tha the accelerometer chips are really difficult to get.  No wonder since there is such high demand.  But fear not, when Ultimarc gets the chips they'll make huge batch of accelerometer boards for all of us to enjoy.  That's thet latest for now. 

[Inventor]

Hi, me again with good news.  The hold-up on the accelerometer chips is over, and the first batch of U-HID-G products is now available.  the price ended up being $49 US.  For that you get a 3-axis accelerometer on a USB interface plus a small expansion header for pots, switches, analog in or other I/O.  I'm putting together an example web page with the guitar application now, so the Guitar Motion Sensing software will be ready soon.  Here is the link to the product: 

http://www.u-hid.com/index.php?option=com_content&view=article&id=21&Itemid=24

[flo]

Looks interesting! I'll have a read...

[Inventor]

Oh, also I'm not sure if I mentioned this, but since I approached Ultimarc with the idea and helped them develop it and such, they have decided to compensate me with a share of the profits.  So I'm not impartial and may be a bit of a cheerleader for my own projects, heh.  Whatever.  Just thought I should mention that. 

[Inventor]

Hi folks,

I emailed Andy at Ultimarc and he said that sales have been slow to musicians.  I just thought I'd post here to ask why that might be.  It's pretty cool to be able to vary effects just by moving your guitar around, so I wonder if people just don't know about it?  Or is $49 too high of a price for such a thing?  Or is it just the economy?  Please clue me in, i'm a little clueless here.