Here is a simple project where you turn an old house phone into an Ipod headphone. From there the possibilities are endless. I sometimes try and fool my friends into thinking that I am actually talking on the phone when in fact I am listening to my music. Note: The microphone will not be recognized by the ipod. I used some soldering in this project due to the fact that I broke the wires to the speaker and had to reconnect them.
Step 1: Why Adding a Mic Is Complicated
When I originally made this intractable the concept of how an iPod mic works was beyond me. I am inserting this step to better explain why i could not simply ad the mic. iPod headphones that have microphones sometimes have a button as well. Normal headphone jacks have three pins. A mic headphone jack has four pins. I have not found anywhere to just buy a four pin 2.5mm jack. The only way i know of buying one is the headphones that have the mics already attached. Griffin Technology does sell microphone adapters for headphone in which you can use it when wiring up the headset.
iPod compatible headphone with mic often have a button that can be used to play/ pause the music. the button is wired to the ground pin and the mic pin. From what i can find it appears that a diode is used in the process. My guess is that there is a current that constantly goes to the mic and ground pin. This current is AC power and when the button is pressed the current goes through the diode becoming one direction DC power. By obstructing the signal the ipod then detects the button is pressed and preprogramed responses are initiated. That's my theory anyways.
Step 2: Materials
1 - old house phone (the ones that have cords attached to them)
1 - old headphone cord (only need the cord and the jack)
1 - knife or wire cutters
1 - roll of electrical tape
1 - screwdriver
1 - Ipod or device where a headphone is used.
Materials needed if wires get detached from speaker
1 - pliers (helps to hold the wire in place)
1 - Soldering device and solder
Step 3: Take Apart the Old Phone
The old phones are the best to use because the phone cord will be replaced with a headphone cord.
The first thing to do is locate all of the screws. Use the correct type of screwdriver to unscrew the screws. A philips screwdriver is used to unscrew a philips type screw. The next thing to do is pry the phone open. Most phones are attached together by an inside piece of plastic and the piece keeps the phone sealed. You must either break the place where the phone is sealed or find where the plastic piece is and push it back. You can use a knife to pry the two halves of the phone apart.
Step 4: Cut the Headphone Cord From the Headphones.
The headphone speakers will not be used but can be if desired. Take an old headphone and cut the cord from the speakers. Strip the cord two inches back to reveal all of the wires. Strip the two covered wires back by one inch. There should be wire around the two covered wires. This wire is important and do not cut it away as it makes up the third wire.
Step 5: Cut the Phone Wires From the Phone Jack
The jack of the phone is usually at the end and it is where the phone cord is attached to. Using either a knife or wire cutters, cut the wires from the jack. The jack can be discarded. Strip the phone wires a half inch back to reveal the wires.
Step 6: Connect the Phone Wires to the Headphone Wires
The best way to attach the two wires securely is to take each wire and separate the strands. Then, take the loose strands of each wire and combine them. After combining the wires, twist the wires together. Apply electrical tape around the wire connections.
The first thing to do before connecting the wires is to locate the wires within the phone. On the phone you will see two wires from the speaker and two wires from the microphone.
If you want to connect the microphone as well then read this paragraph. Picture the microphone as the left speaker of a headphone and the speaker the right speaker of a headphone. Looking at the phone with the speaker at the top and the microphone at the bottom you will notice that there is a left wire and a right wire. When I connected the wires I used the left side to connect to the uncovered wires of the headphone jack. The right side was then connected to the uncovered wire of the headphone jack. Connecting the wires will be explained further down.
The second thing to do before connecting the wires is to locate the wires from the headphone cord. A standard headphone has three type of wires. Two wires are covered in a plastic coating. The third wire is not covered with a coating and it surrounds the two wires.
If you had followed the cord to the headphone speakers you would find how the speakers are connected. Headphones have both a right and a left speaker. Each of the speakers has its own wire. One of the covered wires goes to the left speaker and the other goes to the right speaker. The third wire is divided in half and is sent to both speakers. The third wire is the uncovered wire.
Enough with the history lesson it is time to connect the wires. Connect one of the covered wires from the headphone to the wire on the left side of the speaker. If connecting the microphone, connect the other covered wire from the headphone cord to the wire on the left side of the microphone. If you decide not to connect the microphone then either add another speaker or connect the other covered wire with the covered wire already connected to the left side of the speaker. The hard part will be to split the third wire in half. Split the third wire in half by pulling half of the strands away from the other half of strands. Using one half of the third wire attach it to the wire on the right side of the speaker. Do the same with the other half to the wire on the right side of the microphone. After connecting the wires by twisting them together apply electrical tape around the covered portion of the wires. You do not want the uncovered wires to be able to touch each other.
Step 7: Place Cover Back Over the Phone.
To make the phone look real it is wise to place the cover back on. You might have to break away some of the plastic pieces inside of the back cover. Have the headphone cord exit the phone casing where the old phone cord did. Place the cover back on the phone. If you didn't loose the screws now is the time to put them in their proper place. After putting the back of the phone on the casing it is time to test it out. Place the jack an ipod or headphone jack and listen to some music. Because I tend to do geeky things I made a sound recording of what someone would say on one end of a phone conversation and I would hand the phone to someone and say, "here, someone wants to talk to you." From here it is up to you to decide the fate of the Ipod Head-Phone.
Step 8: Reconnecting the Phone Wires to the Speaker/mic
If you don't know your own strength and happen to disconnect the phone wires from the speaker/mic then read this step. Otherwise you are finished with the instructable. Use a very small portion of solder to reconnect the wire to the speaker/mic. Too much solder and you will get messy. It is important that a piece of solder does not in any way make contact with both speaker/mic connections. After breaking the connection it is best to strip the wire back about half an inch or less. Clean the spot of the connection by lightly scraping the old connection away. You can use the heat of the soldering gun to help break away the wire that was left on the connection. Apply a small drop of solder on the connection and place wire on the drop of solder. Heat the drop of solder and work the wire into the solder until there is enough strands submerged. Let the solder cool and lightly pull the wire to make sure it is attached to the connection. Pulling the wire straight up into the air should be good enough to test the connection. You should now be officially done with the instructable. Hope you like it.