Motion sensor to CV conversion?

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, luketeaford, Joe.

Post Reply
User avatar
pugix
Super Deluxe Wiggler
Posts: 3756
Joined: Sat Oct 31, 2009 7:23 am
Location: Asheville, NC
Contact:

Motion sensor to CV conversion?

Post by pugix » Sat Feb 16, 2013 4:08 pm

I am thinking about a sound installation where people would be wandering in and out, and wondering if I could have motion detectors sensing their presence/movement and generating CV to control the synthesizer.

Does anyone know of a battery-powered motion sensor that could be tapped to produce some CV? It should have adjustable range/sensitivity.

Maybe I could modify a portable alarm or light and have it put out a control instead of an alarm. The light might even provide feedback to the people triggering it.

Here's a light:

http://www.walmart.com/ip/Mr.-Beams-Sec ... t/16664171

Problem is that it only works in dark ambient light.

Here's a wireless doorbell motion sensor.

http://www.smarthome.com/30611/Honeywel ... 02N/p.aspx

I could modify the chime (also battery powered) to get a CV out.

Thoughts?
Richard
https://www.pugix.com

FS/US Erica Swamp, Pico Out, Sheep, Pithoprakta

"Everything in our world is actually always modulated by everything else." - Peter B

User avatar
beeedy
Common Wiggler
Posts: 129
Joined: Sun Nov 11, 2012 4:33 pm
Location: St. Paul, MN

Post by beeedy » Sat Feb 16, 2013 5:32 pm

I feel that the best you could do with the wireless doorbell or light is output a gate/trigger signal. Both of those little guys will most likely have some sort of microcontroller in them reading the sensor values and flipping a relay. So sadly, no analog!

It may be worth looking into an Arduino and some sensors. The Arduino has many very cheap and easy to use sensors that seem they work just fine for your project! One particular sensor that comes to mind is a ultrasonic range finder. Can be used to measure distances with ultrasound, but with some simple code it could also be used to detect motion.

All you would need then is a DAC to convert the digital signal from the Arduino into a CV for your synth. There are many topics on this forum and across the web on how todo such this.

3$ ultrasonic range finder: http://dx.com/p/hc-sr04-ultrasonic-sens ... ule-133696

User avatar
Revok
Ultra Wiggler
Posts: 784
Joined: Sun Jan 15, 2012 12:11 pm
Location: Phoenix

Post by Revok » Sat Feb 16, 2013 6:24 pm

This is a great concept.

Here is a pretty detailed description of the PIR sensors:

http://www.ladyada.net/learn/sensors/pir.html

It would be cool to wire a bunch of these to the HL Midi CPU and have a complex motion controller. Midi-cv would be needed so there probably are simpler ways.

Maybe experimenting with some photo-resistors could be a crude but simple approach.

User avatar
Revok
Ultra Wiggler
Posts: 784
Joined: Sun Jan 15, 2012 12:11 pm
Location: Phoenix

Post by Revok » Sat Feb 16, 2013 6:30 pm

Using something like this for the sensors would kill it:
http://www.parallax.com/tabid/768/produ ... fault.aspx

User avatar
Revok
Ultra Wiggler
Posts: 784
Joined: Sun Jan 15, 2012 12:11 pm
Location: Phoenix

Post by Revok » Sat Feb 16, 2013 6:46 pm

Sorry if I'm spamming here but I got way too into this one. In addition to motion, you could place various mics throughout the space and use this circuit:
http://www.circuitstoday.com/frequency- ... -converter

It could be cool to put the mics near on on the floor so footsteps would send control the voltage.

User avatar
pugix
Super Deluxe Wiggler
Posts: 3756
Joined: Sat Oct 31, 2009 7:23 am
Location: Asheville, NC
Contact:

Post by pugix » Sat Feb 16, 2013 7:29 pm

Revok, thanks for the spam! 8_)

Looks like I will have to put on my experiment's hat and try out some of these circuit ideas. I'll spend more time researching tomorrow.
Richard
https://www.pugix.com

FS/US Erica Swamp, Pico Out, Sheep, Pithoprakta

"Everything in our world is actually always modulated by everything else." - Peter B

don h
Wiggling with Experience
Posts: 340
Joined: Sun Jun 21, 2009 3:50 pm

Post by don h » Sat Feb 16, 2013 8:06 pm

You might look at microwave sensors too, here's one:
http://www.openimpulse.com/blog/product ... or-module/

User avatar
CJ Miller
Super Deluxe Wiggler
Posts: 4256
Joined: Thu Apr 28, 2011 3:10 pm
Location: Mumfordshire

Post by CJ Miller » Sat Feb 16, 2013 8:20 pm

I don't know if they're suitable for this installation in particular, but the Sharp analog optical sensors are quite easy to use. They are powered by and output analog voltage, so at most a CV processor module might be needed to bring the output to a usable range. There are a few kinds, which cover differing range of proximity. I have experimented a bit with the close ones for hand jive.

http://www.pololu.com/catalog/product/1137

edit: FYI they use "JST" connects. I hadn't seen these before, which was a small hitch for me. It's a cable header type which is fairly common with Japanese stuff.

User avatar
oozitron
solder fume huffer
Posts: 851
Joined: Fri Jan 23, 2009 6:11 pm
Location: in a beautiful place out in the country

Post by oozitron » Sat Feb 16, 2013 9:36 pm

An idea: Since some of these sensors (I've been playing with a Sharp distance sensor a bit) will sometimes produce an outout voltage that jumps around, running them through a slew (glide/portamento) will remove those drastic jumps.

And once you've got them smoothed out, run them into a CGS Slope Detector. This can be used to fire off events (advance sequencers, gate envelopes, etc) when the voltage changes. Very cool :-)

Drew
Never want to come down, never want to put my feet back down on the ground

Jarno
Super Deluxe Wiggler
Posts: 2837
Joined: Mon Nov 15, 2010 6:34 am
Location: Rosmalen, NL

Post by Jarno » Sun Feb 17, 2013 3:19 am

+1 on combining sensors, you might also use strain gauges in the floorboards, or walls. Maybe add pir for simple on/off triggering. And ultrasonic rangesensors, hook it all up to an arduino. Or get one of the doepfer diy interfaces to midi, thats even simpler. not sure how to hook the ultrasonic sensors up to this.

User avatar
spunkytoofers
Wiggling with Experience
Posts: 309
Joined: Sat Sep 29, 2012 12:47 pm

Post by spunkytoofers » Mon Feb 18, 2013 1:31 am

take a peak at nerdy robot webstores. just google search. alot of them make pre-fab sensors that will output 0-5v without programming a microprocessor. maybe a little pricier but worth it for me because i just can't get into coding quite yet. works great. i used a vex robotics accelormeter for a different but similiar project

User avatar
pugix
Super Deluxe Wiggler
Posts: 3756
Joined: Sat Oct 31, 2009 7:23 am
Location: Asheville, NC
Contact:

Post by pugix » Mon Feb 18, 2013 6:29 pm

I like the idea of a sensor that puts out voltage. I can build analog circuitry around that and not have to get into a whole arduino thing, which I simply have no time for.
Richard
https://www.pugix.com

FS/US Erica Swamp, Pico Out, Sheep, Pithoprakta

"Everything in our world is actually always modulated by everything else." - Peter B

wmonk
Common Wiggler
Posts: 241
Joined: Thu Jun 03, 2010 1:01 pm
Location: Utrecht, The Netherlands

Post by wmonk » Tue Feb 19, 2013 1:37 pm

In Gent lives Belgian artist Godfried-Willem Raes, who built quite a lot of automated instruments. In his performances he also uses sensors to trigger these automated instruments.
His website is full of information on how he built the instruments and the sensors. It might be interesting.
Although a little warning, it can be a bit weird sometimes :eek:

http://logosfoundation.org/index-god.html
My Website: kits in Europe
My Weblog

User avatar
raisinbag
Super Deluxe Wiggler
Posts: 1708
Joined: Thu Aug 18, 2011 11:40 pm

Post by raisinbag » Tue Feb 19, 2013 2:03 pm

How close could you put the sensors the people? The theremin from PAIA might work? You could probably even run the wands a little bit away from the unit? You would have cv and gates already "ready" for the modular world.

User avatar
instruments of things
Learning to Wiggle
Posts: 22
Joined: Wed May 08, 2019 3:50 pm
Location: Kiel, Germany
Contact:

2.4SINK Eurorack Sensor Interface

Post by instruments of things » Wed May 15, 2019 5:24 am

Hi,

maybe a little bit late, but we just released a wireless Eurorack sensor interface module "2.4SINK". It's currently available on Kickstarter:

Image



The module offers 16 x 12 bit multimode outputs.
Furthermore we have created a custom firmware for Movesense sensors including 9 degrees of freedom sensor fusion for high precision motion control and low latency applications.
More information can be found here.

User avatar
pugix
Super Deluxe Wiggler
Posts: 3756
Joined: Sat Oct 31, 2009 7:23 am
Location: Asheville, NC
Contact:

Re: 2.4SINK Eurorack Sensor Interface

Post by pugix » Wed May 15, 2019 7:23 am

instruments of things wrote:Hi,

maybe a little bit late, but we just released a wireless Eurorack sensor interface module "2.4SINK". It's currently available on Kickstarter:

Image



The module offers 16 x 12 bit multimode outputs.
Furthermore we have created a custom firmware for Movesense sensors including 9 degrees of freedom sensor fusion for high precision motion control and low latency applications.
More information can be found here.
This looks perfect for projects I've been doing with dance. I built a DIY wireless muscle sensor, but the motion sensor idea is more flexible (if more costly). I'll be spreading the word about the Kickstarter.
Richard
https://www.pugix.com

FS/US Erica Swamp, Pico Out, Sheep, Pithoprakta

"Everything in our world is actually always modulated by everything else." - Peter B

User avatar
dubonaire
Super Deluxe Wiggler
Posts: 7904
Joined: Sun Jan 17, 2010 10:45 pm

Re: 2.4SINK Eurorack Sensor Interface

Post by dubonaire » Wed May 15, 2019 7:33 am

pugix wrote:
instruments of things wrote:Hi,

maybe a little bit late, but we just released a wireless Eurorack sensor interface module "2.4SINK". It's currently available on Kickstarter:

...

The module offers 16 x 12 bit multimode outputs.
Furthermore we have created a custom firmware for Movesense sensors including 9 degrees of freedom sensor fusion for high precision motion control and low latency applications.
More information can be found here.
This looks perfect for projects I've been doing with dance. I built a DIY wireless muscle sensor, but the motion sensor idea is more flexible (if more costly). I'll be spreading the word about the Kickstarter.
This must be a record for an OP replying to a 6.5 year necropost!

It looks great!

User avatar
av500
Super Deluxe Wiggler
Posts: 1771
Joined: Mon Feb 02, 2015 8:11 am
Contact:

Post by av500 » Wed May 15, 2019 1:36 pm



Post Reply

Return to “Music Tech DIY”