BORING STANDARD DISCLAIMER! You may render your device/car/yourself unusable. If you decide to install this in your car then for safety reasons please only use it when the car is not moving.
Ever since i got the 770 i've been trying to figure out what to do with it. It's an awesome device - it runs linux, it has a great screen, it has wlan, it has...a lot. On the other hand it's not a phone, it's not a pda, it's not a laptop...
I eventually realized that it would make the perfect in-car entertainment computer and started planning the project. In september 2006 the build started.
hardware
Storage
For storage i decided on the LaCie Mobile 100Gb drive. It's easy to fit in the car, it's bus-powered and it's kind of nice looking.
USB host mode
The Nokia 770 can act as a USB host if it's in rd mode and the usb host mode flag is enabled. These features are activated using the flasher tool from nokia (flasher --enable-rd-mode --enable-usb-host-mode).
There is a quirk. The 770 does not act as a USB host in the regular sense - it does not put out the specified 5 volts. The solution for this suggested by, among others, the thoughtfix blog is to hack a regular usb hub to send 5 volts to the host port as well.
I had an old USB hub laying around and decided to just solder a wire from one of the slave ports to the host connector, like so:
Power supply
We need power for the usb hub (and attached devices) and for charging the 770. We also need some way of disabling the power supply when the 770 is not in use to avoid draining the car battery.
This is the power supply i put together:
The adjustable power supply is used to supply the usb hub with power. It's rated at 1.5A which should be enough to power several usb devices.
The charger for the 770 is just a regular Nokia (well, actually a copy) car charger taken out of its case.
The relay board is a relay wired to control the power supply. When the relay is open the circuits will not draw any current (nor will they work). The circuit will be closed by a microgap switch hacked into the case of the 770 (more about that later).
The current bench build
This is what the current bench build looks like. The power supply needs a plastic housing, but other than that this is what's going to be installed in the car (except for the 12 volt regulator to the left).
software
For now this is just some scattered thoughts and a few links. I'll get to software once the hardware is built.
