My next project - iPhone FM Modulator

Last year I bought an iPod/iPhone adaptor so that I can connect my iPhone to my car radio directly without using a cassette adaptor or FM Transmitter. Neither of the options mentioned charge your phone as you listen to it. The FM Transmitter idea is also bad in that it fades in and out, and more often then not, it is swamped by strng radio signals as you drive around.

The direct connection adaptor that I bought, a PA-NIS11 unit basically "add" an option to the CD button, making the radio think it is conected to a multiCD changer, thus make s your iPhone or iPod sounds like it is coming from a CD. Unfortunately, the unit I bought is only compatible with certain Nissan MaximaBose radios that DO NOT have the 6-CD changer built-in. Mine is, and thus not usable. I ended up installing that in Jan's car and it worked great there.

So I investigated of modifying the radio itself, so that it will switch input from CD to iPod/iPhone by modifying the circuit board and adding auxiliary input. I actually know how to do this, and even managed to get the schematic for my radio. Unofrtunately, all my electronic component parts are in Texas and it would take to much time sorting and finding what components I need to make this happen. lately I decided that I can use a generic FM modulator that mounts behind the radio, and switched out the car's antenna and inject the FM signal from the iPod/iPhone directly into the radio's antenna input. In theory, the signal should be so strong that no outside radio signal can interfere, and with the external antenna disconnected, the radio should only see the FM signal from the modulator. However, that does not provide the second thing that I want, that is being able to charge the iPod/iPhone as it is being used.

So, this week I've ordered a generic FM modulator ($20), an iPod/iPhone cable ($6) that on one end has a typical 30-pin connector and the other end has Audio RCA jacks, and a USB connector. I will first modify the FM modulator to add a 5 volt DC output using using an LM 7805 3-terminal regulator fromRadio Shack ($2) needed to charge the iPhone, and connect this output to a USB (female) connector ($3). So for under $50, I will soon have an interference free iPod/iPhone adaptor that will also charge my phone. Isn't that nifty?

I googled many places and have not been able to find something like the one I am about to do cheaply. I think there is a product called iSimple Gateway or iSimple Soundbyte, but they cost over $100.