mindtrip
Well-known member
I apologize if this post is not in the correct forum; it is a farkle, though not attached to the bike....
The Problem:
I recently installed a StarCom system for an upcoming tour of the Oregon/Washington coast. My girlfriend tours with me, and thus far we've used our own iPods with in-ear monitors for entertainment, and hand signals for communication. On this
tour a buddy is coming along who wanted bike-to-bike communications; thus the StarCom. My girlfriend wanted to be able to listen to the radio conversations, as well as talk to me, but I realized that if I didn't do something, she was going to wind up running the iPod. We have different musical tastes, and while we both listen to audiobooks we're usually into different books at any given time. This meant I was going to have to listen to her stuff the whole time. Unacceptable!!!
The Solution:
We use in-ear monitors, so I got the StarCom headsets that allow the use of your own headphones. I quickly realized this would make it possible to rig up some kind of switch or patch cable system that would allow her to listen to her own iPod if she didn't want to listen to whatever I had running on mine, but switch over to the intercom if I needed to talk to her. I scoured the internet looking for solutions, as well as all my local electronics stores, to no avail. No one makes a switchable audio input for personal headset use. However, I DID find a switch at RadioShack that lets you switch between computer audio input and an auxilliary audio, as well as switching output between computer speakers and headsets (clicky. And for only $2!! I figured if it were small enough, she could stick this in her pocket and switch between the intercom and her iPod at will.
Alas, this item is designed for sitting on a desktop next to your computer. That means that they made it far to large to conveniently carry in a pocket. I bought it anyway, thinking that perhaps I could rip the box apart and cut off any bits I didn't need to still make it work for my purposes. For two bucks, I could smash it up with a hammer and not really be out anything. After taking the box apart I found a single PCB with lots of tracings, but realized it would not be as simple as cutting out whatever I didn't need--the two separate switches were linked, and there were microphone inputs as well. Lots of stuff taking up unnecessary space! As I was contemplating my predicament, I pulled my iPod out of my work bag and disconnected it from the MintyBoost (clicky) that a friend made for my birthday last year, when I had an 'aha!' moment. Time to make...... MintySwitch!
After a trip back to RadioShack, I now had PCB, three 1/8" audio jacks, and some wire--the switch I would steal off the computer audio switch. A trip to Walgreen's yielded a box of Altoids Chewing Gum (spearmint, of course!), and away we go!
The first step was to steal parts off the computer switch.
At first I was going to use the audio jacks out of this as well, but bought the RadioShack ones because 1) the ones on the computer switch were very tall, and might have interfered with closing the case lid--I could have cut out portions of the lid as well, but didn't want to have exposed sharp edges that might lead to cut fingers; and 2) the RadioShack jacks have threaded ends with a nut that allows them to be firmly fixed to the sides of the case. I figured this would give good support for the audio switch and keep things from moving around in the case.
After using my desoldering tool, I had the switch:
Next was to simply cut the PCB to the correct shape with an ever-handy Dremel tool, then figure out jack placement. Since I didn't want the switch to accidentally activate in her pocket, I decided to run the switch in-line with the long axis of the case. The 90-degree headphone plug would conveniently come out of the bottom, and I ran the audio inputs on the side opposite the hinged lid.
More dremeling and the cutouts for the switch and headphone jack were done. I lined the bottom of the case with double-sided foam tape, both to help keep things from moving inside the case, and to insulate the switch pins from the metal of the case. Those metal tabs on the top of the switch are actually the ends of the pins, going all the way through the switch body. If you don't insulate those somehow, the switch doesn't work as a switch, but is simply a splitter/joiner instead. (Note that in the picture I originally cut out the foam under the switch so the board would lay more perfectly horizontal since the switch is taller than the audio jacks, with the plan of covering the pins with electrical tape. After a trial assembly I scrapped that idea as, even with the audio jacks screwed in, there was still too much movement in the case for my liking. So I peeled off the cut double-sided tape and replaced it with fresh, uncut tape.)
Getting the switch and the jacks to fit on the PCB actually required dremeling the PCB holes. The holes present in the PCB weren't large enough to accommodate the pins on the audio switch or the jacks, and the pattern of the pins on every piece did not nicely match up with the pins on the board--go figure! But a bit of dremeling and everything fit.
Since I was going to be mounting the jacks upside down inside the case, I needed a way to hold everything in place so I could figure out where to cut the holes for the input jacks. I found that sewing pins and needles worked quite well!
I did have to elongate all the holes on one side so they would allow the jacks to slide in at a 45-degree angle. I think if I were to make another one, I'd move the switch over to the hinged side enough to allow a jack to mount beside it, so I could put all three audio jacks on the same side--make it a LOT easier to cut the holes.
With the holes cut, I only needed to solder everything in place:
Note that the three audio jacks all have a ground wire, which is the foremost pin directly under the jack opening. I didn't need to know which part of the jack was the right channel and which was the left, I only needed to wire all three jacks to the switch in the same way. The switch itself has 3 pairs of pins arranged in 2 columns; think about the columns as "right" and "left" channels. The center pair of pins is where the output jack connects, and the input jacks connect on either side of the output pins. So the green wires are ground (of course), and with these all connected to each other, the system is properly grounded through the intercom. The red wires are one channel, the black are the opposite channel.
I used 22-gauge stranded wire. I really wanted to use 24-gauge, but RadioShack only had 22-gauge in a 3-color pack. The only 24-gauge wire in the store was paired speaker wire, which would also work fine but might be more confusing when wiring. As a result, the wire didn't fit through the holes in the jack pins unless you peeled some of the strands back, which I did. I then threaded them through the pins, put the peeled strands alongside the pins, and soldered it all in place. Probably overkill. If you ever do this project yourself and use solid-core wire, make SURE you get 24-gauge; I don't know how well a solder joint would hold to a solid wire that could not be threaded through the pin and wrapped back on itself.
When the soldering was done, I peeled off the double-sided foam tape backing, inserted the PCB, screwed the jacks onto the case, and voila! MintySwitch!
Bonus to this project:
Yummy gum!!
The Problem:
I recently installed a StarCom system for an upcoming tour of the Oregon/Washington coast. My girlfriend tours with me, and thus far we've used our own iPods with in-ear monitors for entertainment, and hand signals for communication. On this
tour a buddy is coming along who wanted bike-to-bike communications; thus the StarCom. My girlfriend wanted to be able to listen to the radio conversations, as well as talk to me, but I realized that if I didn't do something, she was going to wind up running the iPod. We have different musical tastes, and while we both listen to audiobooks we're usually into different books at any given time. This meant I was going to have to listen to her stuff the whole time. Unacceptable!!!
The Solution:
We use in-ear monitors, so I got the StarCom headsets that allow the use of your own headphones. I quickly realized this would make it possible to rig up some kind of switch or patch cable system that would allow her to listen to her own iPod if she didn't want to listen to whatever I had running on mine, but switch over to the intercom if I needed to talk to her. I scoured the internet looking for solutions, as well as all my local electronics stores, to no avail. No one makes a switchable audio input for personal headset use. However, I DID find a switch at RadioShack that lets you switch between computer audio input and an auxilliary audio, as well as switching output between computer speakers and headsets (clicky. And for only $2!! I figured if it were small enough, she could stick this in her pocket and switch between the intercom and her iPod at will.
Alas, this item is designed for sitting on a desktop next to your computer. That means that they made it far to large to conveniently carry in a pocket. I bought it anyway, thinking that perhaps I could rip the box apart and cut off any bits I didn't need to still make it work for my purposes. For two bucks, I could smash it up with a hammer and not really be out anything. After taking the box apart I found a single PCB with lots of tracings, but realized it would not be as simple as cutting out whatever I didn't need--the two separate switches were linked, and there were microphone inputs as well. Lots of stuff taking up unnecessary space! As I was contemplating my predicament, I pulled my iPod out of my work bag and disconnected it from the MintyBoost (clicky) that a friend made for my birthday last year, when I had an 'aha!' moment. Time to make...... MintySwitch!
After a trip back to RadioShack, I now had PCB, three 1/8" audio jacks, and some wire--the switch I would steal off the computer audio switch. A trip to Walgreen's yielded a box of Altoids Chewing Gum (spearmint, of course!), and away we go!
The first step was to steal parts off the computer switch.
At first I was going to use the audio jacks out of this as well, but bought the RadioShack ones because 1) the ones on the computer switch were very tall, and might have interfered with closing the case lid--I could have cut out portions of the lid as well, but didn't want to have exposed sharp edges that might lead to cut fingers; and 2) the RadioShack jacks have threaded ends with a nut that allows them to be firmly fixed to the sides of the case. I figured this would give good support for the audio switch and keep things from moving around in the case.
After using my desoldering tool, I had the switch:
Next was to simply cut the PCB to the correct shape with an ever-handy Dremel tool, then figure out jack placement. Since I didn't want the switch to accidentally activate in her pocket, I decided to run the switch in-line with the long axis of the case. The 90-degree headphone plug would conveniently come out of the bottom, and I ran the audio inputs on the side opposite the hinged lid.
More dremeling and the cutouts for the switch and headphone jack were done. I lined the bottom of the case with double-sided foam tape, both to help keep things from moving inside the case, and to insulate the switch pins from the metal of the case. Those metal tabs on the top of the switch are actually the ends of the pins, going all the way through the switch body. If you don't insulate those somehow, the switch doesn't work as a switch, but is simply a splitter/joiner instead. (Note that in the picture I originally cut out the foam under the switch so the board would lay more perfectly horizontal since the switch is taller than the audio jacks, with the plan of covering the pins with electrical tape. After a trial assembly I scrapped that idea as, even with the audio jacks screwed in, there was still too much movement in the case for my liking. So I peeled off the cut double-sided tape and replaced it with fresh, uncut tape.)
Getting the switch and the jacks to fit on the PCB actually required dremeling the PCB holes. The holes present in the PCB weren't large enough to accommodate the pins on the audio switch or the jacks, and the pattern of the pins on every piece did not nicely match up with the pins on the board--go figure! But a bit of dremeling and everything fit.
Since I was going to be mounting the jacks upside down inside the case, I needed a way to hold everything in place so I could figure out where to cut the holes for the input jacks. I found that sewing pins and needles worked quite well!
I did have to elongate all the holes on one side so they would allow the jacks to slide in at a 45-degree angle. I think if I were to make another one, I'd move the switch over to the hinged side enough to allow a jack to mount beside it, so I could put all three audio jacks on the same side--make it a LOT easier to cut the holes.
With the holes cut, I only needed to solder everything in place:
Note that the three audio jacks all have a ground wire, which is the foremost pin directly under the jack opening. I didn't need to know which part of the jack was the right channel and which was the left, I only needed to wire all three jacks to the switch in the same way. The switch itself has 3 pairs of pins arranged in 2 columns; think about the columns as "right" and "left" channels. The center pair of pins is where the output jack connects, and the input jacks connect on either side of the output pins. So the green wires are ground (of course), and with these all connected to each other, the system is properly grounded through the intercom. The red wires are one channel, the black are the opposite channel.
I used 22-gauge stranded wire. I really wanted to use 24-gauge, but RadioShack only had 22-gauge in a 3-color pack. The only 24-gauge wire in the store was paired speaker wire, which would also work fine but might be more confusing when wiring. As a result, the wire didn't fit through the holes in the jack pins unless you peeled some of the strands back, which I did. I then threaded them through the pins, put the peeled strands alongside the pins, and soldered it all in place. Probably overkill. If you ever do this project yourself and use solid-core wire, make SURE you get 24-gauge; I don't know how well a solder joint would hold to a solid wire that could not be threaded through the pin and wrapped back on itself.
When the soldering was done, I peeled off the double-sided foam tape backing, inserted the PCB, screwed the jacks onto the case, and voila! MintySwitch!
Bonus to this project:
Yummy gum!!
