I own an old car (1999 Mercury Tracer) with no aux/cassette input. I was left with just an AM/FM receiver for which I was using an FM transmitter to listen to my own music collection. This had a bunch of problems
1. It had an SD card input. But I would often forget/be too lazy to take the SD card with me to update my music collection.
2. It had an aux input. There are versions which even support A2DP connections. Both of these require me to take out my phone every time I am driving which is not fun. Often times I leave my phone at home when going for short drives. Also both require me to use my phone when driving (to change the music). This was a big problem for me.
It recently stopped working. So I made a version of my own using RPi. It transmitted FM using PiFM when the car was on. When the car was powered off it just connected to my home WiFi and idled. I could then connect to it via SSH and update my music from the comfort of my desk! I powered it using a cellphone battery pack when the car was off. This worked in theory but the sound itself was horrible with lots of distortion. So, I dropped the idea.
I was wondering if this idea can be updated for modern cars. Here is what I was thinking of doing when I eventually buy a new car
1. Most cars today have a USB input. We could share a USB drive between the car stereo and RPi. I was thinking we could switch between the two using relays.
2. By default USB is always connected to the car stereo. But via SSH command we can switch over the data lines to RPi and mount the USB drive. Then we can update the music and return the data lines to their default state.
This way we can always have updated collection in the car without having to always take out our phone or remembering to take the USB home to update it!
With the recent announcements of RPi Zero and CHIP we have choice of two low power devices that could potentially do this task!
How does this idea sound?!