In this Instructable we'll take a look at the inner workings of the in line remote. We will then create a larger remote that will fit inside of an Altoids Smalls tin.
- Expendable or broken set of iPhone/ iPod Touch Ear Buds with Remote
- Altoids Smalls tin
- 3 small push buttons
- 1/8" stereo jack
- small Perfboard
- pair of right angle headers
- small rubber grommet
- Soldering iron
- Wire cutters/strippers
- Razor blade
- Small torch or lighter
- Sanding block with 150 grip sand paper
- Jeweler's file set.
Step 1: Inside the Remote
After hours of research and experimenting, with my limit knowledge, i have no idea how it all works. What i could find online seams to indicate that the circuit board in the remote triggers the iPhone/iPod into excepting various signals between the Ground and Control/Mic wires. I do know that the Play/Pause/Skip button shorts the Control/Mic wire to Ground. But if you connect a TRRS jack up to the phone, start up some music, and short the Control/Mic wire to the Ground wire, nothing happens. But if you short those wire at the remote you will trigger the iPod to ply/pause/skip. As for how the circuit triggers volume control i have no idea.
Here is what i do know. When the headphones are plugged in there is about 1.9V DC on the Control/Mic and Ground wires. When the cable is not connected to anything there is about 0.87 Ohms on the wires. When the Volume + button is pressed the resistance drops to 0.85 Ohms. When the Volume - is pressed the resistance drops to 0.86 Ohms. That doesn't really mean much since there is more going on there then a couple of resistors. From what i can make out there is 1 transistor on the board and an IC with 6 leads.
So to keep things simple we will used the existing board and just extend the buttons on the board to our larger push buttons.