Well, folks, here's a little project I just finished that I thought I'd share. It's simple and fairly quick and useful as all getout to me.
Here's what you need:
Normally open momentary switch. I had one of these laying around, but any will do. http://www.madvapes.com/Horn-style-switch--Black_p_2086.html -- Black Radio shack has them in spades.
Something to put the switch in. I used a black bottle top from some fuel treatment, I think. Quart of oil cap. Project box. Whatever.
Plumbers epoxy. Or JB weld. Or regular epoxy. Whatever. I used plumbers epoxy, because it's like putty and I had some on hand
Some way to mount it on your bike. I used some double-sided tape that came with an LED kit for my wife's bike. Now that I think on it, velcro would probably be the e-ticket
Some wire. Any gauge will do. I think I used 22 or something.
Heat shrink or electrical tape.
The garage door remote you already have.
Soldering iron and solder, of course...
Here's what I didn't take pictures of:
Solder one wire to each post of your switch. Make sure your wires are long enough to reach wherever you want to stash the real garage door opener.
Mount the switch in whatever you're putting it in. Since I used a bottle cap, I drilled the top of the cap. Used a dremel with one of these to notch a place for the wires to come out in the bottom. You could do it with a file or something.
Make sure the switch and wires are where you want them, and fill the cap with epoxy so it's flat on the bottom. I peeled one side of my double sided tape and put it in the glue while it was drying.
After that's dry, put your heat shrink on the wires for whatever length you want. Or just tape them up. Protects the wires a bit and makes it look cleaner.
Okay, so the switch is made.
Pick where you want your button to be. I put mine under the left side of the tank, where it was about flush with what you see of the tank.
Next, run your wire from there to wherever you're going to stick the actual opener. I put mine under the seat. Zip ties are your friend.
Okay, now is the time to stick your switch in place, and we can get on to the interesting bit. The remote.
Open up the remote and figure out what button on it opens the door. Usually these things are four-posted, a pair on each side of the switch. You have to figure out where to connect your wires. I used a meter to ohm it out, but you can usually see it on the circuit board. You want to pick the ones that are not connected by a line. Using a meter, set it to ohms. Pic two posts, you should read 1, then press the button and you should read close to 0 ohms. Here it is already connected:
That's the hard part. Now all you have to do is notch the remote for the wires to come out, put the board back in and stash it.
That's it. Woohoo. No more digging in pockets or getting off to punch in the code for me.

Here's what you need:
Normally open momentary switch. I had one of these laying around, but any will do. http://www.madvapes.com/Horn-style-switch--Black_p_2086.html -- Black Radio shack has them in spades.
Something to put the switch in. I used a black bottle top from some fuel treatment, I think. Quart of oil cap. Project box. Whatever.
Plumbers epoxy. Or JB weld. Or regular epoxy. Whatever. I used plumbers epoxy, because it's like putty and I had some on hand
Some way to mount it on your bike. I used some double-sided tape that came with an LED kit for my wife's bike. Now that I think on it, velcro would probably be the e-ticket
Some wire. Any gauge will do. I think I used 22 or something.
Heat shrink or electrical tape.
The garage door remote you already have.
Soldering iron and solder, of course...
Here's what I didn't take pictures of:
Solder one wire to each post of your switch. Make sure your wires are long enough to reach wherever you want to stash the real garage door opener.
Mount the switch in whatever you're putting it in. Since I used a bottle cap, I drilled the top of the cap. Used a dremel with one of these to notch a place for the wires to come out in the bottom. You could do it with a file or something.
Make sure the switch and wires are where you want them, and fill the cap with epoxy so it's flat on the bottom. I peeled one side of my double sided tape and put it in the glue while it was drying.
After that's dry, put your heat shrink on the wires for whatever length you want. Or just tape them up. Protects the wires a bit and makes it look cleaner.
Okay, so the switch is made.
Pick where you want your button to be. I put mine under the left side of the tank, where it was about flush with what you see of the tank.
Next, run your wire from there to wherever you're going to stick the actual opener. I put mine under the seat. Zip ties are your friend.
Okay, now is the time to stick your switch in place, and we can get on to the interesting bit. The remote.
Open up the remote and figure out what button on it opens the door. Usually these things are four-posted, a pair on each side of the switch. You have to figure out where to connect your wires. I used a meter to ohm it out, but you can usually see it on the circuit board. You want to pick the ones that are not connected by a line. Using a meter, set it to ohms. Pic two posts, you should read 1, then press the button and you should read close to 0 ohms. Here it is already connected:


That's the hard part. Now all you have to do is notch the remote for the wires to come out, put the board back in and stash it.


That's it. Woohoo. No more digging in pockets or getting off to punch in the code for me.