$5 iphone stereo headset

$5 iphone stereo headset

The iphone 3G is a pretty neat gadget.  One of the problems with a device like this is the headsets can cost a lot if you lose or destroy them.  Instead of paying an arm and a leg for a commercially available stereo headset for your phone, build one yourself where the remote button works and have the ability to use any earbuds for about $5.

Difficulty : EASY
Time: It took longer to write this how-to

Materials:

• 1- 4pin 3.5mm audio jack female (optional)
• 1- 4pin 3.5mm audio jack male
• old cellphone headset or compact microphone with in built button
• ~2ft – 4 conductor enameled wire

Tools:

• soldering iron and solder
• side cutters
• strippers
• shrink tubing and heat gun
• multimeter

Doner head set and 3.5mm 4-pin jacks

The first thing you want to do is cut off the ends on your donor headset and check continuity with your multimeter.  Figure out what wires go where.  You’ll also want to make sure that your button is a momentary contact button.  how the iphone senses that the button is being pushed is the resistance that it normally senses in the mic goes to near zero (i.e. the mic is shorted to ground).

Next you’ll want to wire up the mic.  I had the advantage of having part of an old HTC mogul headset laying around which is already a stereo headset with a mic.  If you don’t have this luxury there are two ways to get your mic wired up.  If you’re the adventurous type you can crack open the mic case and run your 4 conductor wire in to the case.  Otherwise, you can treat the mic like a little dongle off your headphones.  If you’re going to do the dongle I’d suggest tying the dongle to the wire with a couple of zip ties.

inline mic style

dongle mic style

To make the button work properly, solder one end of the button to ground and the other end to the phone side of the mic (button will be in parallel with the microphone).  Many headsets do this already and your doner set might do it this way.  In my case the HTC headset did not so I had to solder the wires together.  Don’t forget to clean the enamel off the wires before you start soldering.  I like to use a solder gun to do this, that way I don’t end up with enamel gook all over the good soldering iron.  Tin the ends up before you try to join them together.

cleaning off the enamel

Now you need to solder on the male and female jacks on the respective ends of the headset.  DO NOT forget to slip the shrink tubing and jack cover on before you begin soldering.  Soldering these ends can be a real pain in the butt, especially pin 2 on the male jack, you don’t want to have to do it twice.  See the pin out chart below for what goes where.

pinouts

The last step is to heat up the shrink tubing with your heat gun and slip the cover over the male 3.5mm audio jack.

shrinking tubing with heat gun

If you did everything right, you can slip a set of earbuds (or headphones) of your choice in and you should get stereo sound.  The button on the mic will not only pick up a phone call it will pause/play your songs on the phone.

Great, you’re done!  Wasn’t that easy?

The finished product