One of my friends was absolutely amazed when I told her that her phone could be used as a quite decent MP3 player. She noted that it would be one less thing she’d have to carry in her purse.
You can do this with smartphones (iphone, Android, Blackberry, etc.) and many other phones. It’s easiest if the phone has a standard 3.5 mm. mini jack, but can be used with other phones with the appropriate adapter.
Step 1: Ways to hook it up in your car
The best scenario is a newer car which have a jack on the dashboard for audio input. Just use a simple 3.5 mm male to male cable to plug your phone into your car’s audio system.
In a couple of rare cases car radios have hidden audio input jacks on the back of the radio. You’ll need to disassemble your dashboard to get access to the radio and figure out a way to string a cable from the back of the radio to a place you can easily reach.
An older car with a cassette radio is the next best choice. Just get an adapter which insets into the cassette’s slot with a cable with a 3.5 mm. plug. Car cassette adapters were originally intended for use with a portable CD player for cars without built-in CD players but are marketed now for MP3 players.
The final choice is a small FM radio transmitter which sends a signal through your car’s radio. This is often the only choice for a car radio which doesn’t have any other inputs.
There are more creative solutions which involve disassembling the car radio and connecting wires directly into the sound circuits or a circuit which emulates an external CD disk changer, but they’re beyond the scope of this tutorial.