From Wired How-To Wiki

If you are a musician, chances are you must have already realized that some gadgets of the trade are exquisitely pricey, despite being very primitive in concept. The sustain pedal is not that expensive, but in its essence, it's just an encased switch. So, why pay anything for something if you can pay nothing?

Besides, if you perform live, you know that most stages don't provide adequate illumination to keep you from tripping over cables and stands during setup.

This flashlight/sustain pedal is an NC (normally closed), momentary (non-lock) action sustain pedal, suitable for use with keyboards, synthesizers, MIDI controllers, guitar amps, etc. Sustain pedals are very useful and if you have a bunch of synthesizers and keyboards and guitars, you will agree that one can't have too many.

Moreover, these days, the "reduce, reuse, recycle" mantra is earbleedingly repeated, although not always accompanied by info on how to exactly act about it, so I hope this little project will satisfy the green-concerned musicians. And it provides that achievement feeling only a true DIY deed can.

What you'll need

Tin can (candy and sardines are excellent, but any squishy involucrum will do)
P10 jack
9V battery clip
1 old flashlight with working LED (preferably crystal type)
1 300 ohm resistor
1 old mouse
1 9V battery
soldering iron, solder, insulating tape

Harvest the components

Open the mouse and extract the tiny switches under the buttons. Some have three, others only two, but the good part is, no matter how old and battered your mouse is, probably at least one switch is working fine (since they are designed to withstand some millions of clicks). You can strip the cable and get the wire you'll need to connect the components together.

Also, take out the LED from the old flashlight, taking care to not to cut the leads too short or melt it if you have to dessolder it. Remember, a LED is just a diode and, therefore, it's heat-sensitive.

Prepare the case

Simply drill holes to pass the jack and the LED tightly through. Find something to fill up the space inside the can, so when you step on it the switch is triggered. Here, I used an empty adhesive tape spool, cut to keep the switch in place.

Assemble it

The switch you took out of the mouse has three terminals: a NO (normally open) lead, a NC (normally closed) lead, and a common lead. Check carefully, they are identified with tiny text. But you can use a multimeter to figure out which is which.

The pedal circuit has two sections: one, normally closed, opens when you press the pedal and thus controls the device at the other end of the cable connected to the jack. The other, normally open, turns on the LED as you press the pedal. These two functions are performed by that same switch, and the two functions work isolated from each other. The battery power never interacts with the equipment you plug the pedal to.

All you have to do is to connect the P10 jack to the NC/common leads, and the NO/common leads to the LED/resistor/battery circuit. Order is not an issue.

I recommend you glue a piece of foamy rubber to the bottom, so when you squeeze the can it activates the switch every time.

Just remember that LEDs do have polarity (the lead coming out of the side with the flat chamber is supposed to be connected to the [-] battery terminal). Don't invert the polarity of any component, and don't skip the resistor to adjust the current, or you will burn the LED. In this case I used a 300 ohms resistor that will work fine for most LEDs. Don't skimp on the electrical insulation, since the can metal is conductive. Also, be sure to set your equipment to accept a NC sustain pedal (check the manual, dude).

Sustain your notes

Close the lid and you are done! The flashlight will last for ages, since the power consumption is almost negligible, and the can will easily take the abuse. Additionally, the LED will light up and provide you visual feedback when the sustain is really on.

--alex_yamamoto 03:31, 9 March 2011 (UTC)