Photo Eye Expression Pedal

Devi Ever · Post by **Devi Ever** » 24 Dec 2007, 12:30

Photo Eye Expression Pedal... replaces most expression pedals with light sensitive control! <@.@>

Here's a video of what it does :

- - -

What you need (supplier, part, and part #) :

= Allied Electronics : http://www.alliedelec.com =
photo cell : 699-0380

= Mouser : http://www.mouser.com =
enclosure : 546-1590H
expression jack : 502-N112BX
photo cell "cover" : 517-SJ-5312CL

= Misc =
hot glue / gun
soldering iron / solder
drill press (hand drill bad!!!) / 3/8" bit
adjustable wrench
screw driver
pliers
finger nail clippers

- - -

sa1126 has some step by step photos of his build here for reference :
http://www.deviever.com/fx/forum/viewto ... f=79&t=860

- - -

:: Drilling
- drill a 3/8" hole on top, middle ways towards the front
- drill a 3/8" hole on the back side, dead center

:: Assembly - photo cell
- place photo cell "cover" over the top hole, gently press down
- flip the enclosure over, place the photo cell onto the under side of the photo cell "cover", with the leads facing the left and right walls of the enclosure (the long sides), gently press down
- (this is tricky), cover exposed back side of the photo cell with hot glue, dabbing down around the edge of the hole so that the glue is mashed down against the enclosure. If you just glob glue down there, it can come off very easily. The dabbing and mashing makes it so that it is _very_ hard to remove the photo eye by accident or on purpose. :')
- let dry

:: Assembly - expression jack
- place the expression jack into the back hole with the round tab facing down, and the two tabs that are round but with square bases facing up
- secure the expression jack to the case with the included nut and washer. The nut will keep going and going as you screw it (because the jack enclosure is plastic), so secure it as tightly as you can, but don't keep twisting forever!

:: Assembly - soldering
- pull the left lead of the photo cell through the left tab of the expression jack (round with square base), making sure that the lead doesn't get in the way of where your expression plug will be when it's plugged in (just to be safe, insert a plug to make sure while you do this)
- do the same with the right lead and the right tab (round with square base). I find using pliers makes this job easier.
- use a finger nail clipper to clip off any excess amount of the leads poking out (you don't want them to accidentally touch the base plate when you close up the enclosure)
- solder each tab
- the round tab facing down should be left alone

:: Assembly - done
- triple check to make sure the leads aren't going to interfere with plugging in an expression plug, or accidentally touch the back plate
- you may have to angle the expression jack left or right a bit so that you can put on the back plate with out an expression jack tab touching it
- go ahead and test the PEEP to make sure it's working
- finally put on the back plate, screw in the four screws, test again, and that's that

:: Usage
- use in a well lit room
- usually you would use a TRS "stereo" cable with the PEEP, but if that doesn't seem to work, try a normal "mono" patch cable
- experiment with different effects knob settings. The PEEP can react differently to different settings than a normal expression pedal

Happy DIYing!

moro · Post by **moro** » 24 Dec 2007, 16:01

That is really cool!

I wonder if you need to use this on a dark stage (for example), you could rig up a bunch of LEDs or something.

RLBJR65 · Post by **RLBJR65** » 26 Dec 2007, 17:14

Somewhere I saw a guy that made a mold that fit over his teeth with a 3v watch battery and an LED in it. He had an LDR mounted at the end of what looked like an old telephone head set (the ones that have the mic out on a wand in front of your mouth) He was using it to control a Wah. Just open and close your mouth to adjust the light / resistance of the LDR.

I wish I could find the link it was hilarious

I once thought of putting an LED in the bottom of your shoe which might be easier. Or mounting an LDR in your guitar and holding a light of some sort in you pick hand

All methods would be greatly affected by stage lighting I would think.
Also you would have to carefully shield anything mounted out of the stomp box.

It's a cool idea if you can get around those issues though

briggs · Post by **briggs** » 29 Dec 2007, 13:25

he he, looks like a fun little device. I'll try and get hold of some really cool little modulation devices a guy I know has been cranking out

snail · Post by **snail** » 29 Dec 2007, 14:08

Nice one, thanks for sharing!

snail

bradyd · Post by **bradyd** » 24 Apr 2009, 20:39

The Peep info has been moved here: http://deviever.com/forum/viewtopic.php?f=151&t=519

RnFR · Post by **RnFR** » 24 Apr 2009, 21:00

RLBJR65 wrote:Somewhere I saw a guy that made a mold that fit over his teeth with a 3v watch battery and an LED in it. He had an LDR mounted at the end of what looked like an old telephone head set (the ones that have the mic out on a wand in front of your mouth) He was using it to control a Wah. Just open and close your mouth to adjust the light / resistance of the LDR.

kinda like this?

arsenicproductions · Post by **arsenicproductions** » 10 May 2009, 04:58

Haha
That's a great video.

Spazzmatazz · Post by **Spazzmatazz** » 20 May 2009, 14:03

I'll try to build one keeping the circuit the simple, but installing a magnifying glass on the photo-resistor.

the magnifying glass I'll used it's desquartized from a bike-lamp.

UZILSD · Post by **UZILSD** » 26 Jun 2009, 17:55

RnFR wrote:
RLBJR65 wrote:Somewhere I saw a guy that made a mold that fit over his teeth with a 3v watch battery and an LED in it. He had an LDR mounted at the end of what looked like an old telephone head set (the ones that have the mic out on a wand in front of your mouth) He was using it to control a Wah. Just open and close your mouth to adjust the light / resistance of the LDR.

kinda like this?

I'll never buy one of those used...