Building a Nomadic Pi is very much up to the owner. So rather than dictating an exact hardware setup I am just going to run through how I made my car computer.
Some of the lessons I learnt along the way. Any pitfalls I encountered and things that I think could have been done better.
After buying all the hardware to build your car computer. It's a challenge to put it all together in a format that won't be damaged in a moving car.
The Official Raspberry Pi touch screen has holes drilled into the back of the screen housing. So they make a great starting point for holding everything together.
The ones near the center allow the Raspberry Pi to piggyback the screen itself. There are then threaded holes closer to the corners that I decided to attach a frame of sorts and build backwards.
Just a word of advice if you decide to follow the same path and screw your framework into the back of the screen. Tighten the screws in really gently! If you overtighten the screen will start to push out the opposite side. So just go very slow and be careful!
Now there is somewhere to mount the housing you just need to decide what you are going to decide what you are going to use to house it.
At the hardware store I found some thin metal strips and angle brackets with predrilled holes. So I decided to create a frame using them as they can easily be bolted together.
This approach is cheap, sturdy and provides lots of handy mount points for holding peripherals (usb hub, external dongles etc) in place.
Commercially available Double Din housings are available to mount devices in the dash. But I still believe it's probably easiest to build the frame around the Pi and then bolt the frame to the housing to hold things in place.
Beside housing the Raspberry Pi and finding a way to mount all the add on devices. Delivering power to everything that needed it was the next hardest step.
First step is take the 12 volt DC power from your car's electrical system and reduce the voltage. The Pi requires off 5 volt power supply.
Fortunately 12 to 5 volt DC voltage converters can be found easily on Ebay or other electronic part suppliers. Pay attention to the amperage rating you will need something that can deliver 3 amps or more.
A voltage converter rated at 3 amps will give a maximum power draw of 15 watts ( 5v x 3 amp = 15watts ). My hardware configuration has a peak power usage of 10.44 watts. That gives an extra 4 watts available but if you plan to run a lot of power hungry devices off the Pi just be aware power could become a problem.
After the voltage has been dropped I power flows to the power USB hub. Along with a micro USB connector to power the Raspberry Pi.
The external GPS antenna is not a requirement as most GPS devices ( hats or USB sticks ) will have a passive antenna inbuilt. One thing to keep in mind is the intended installation location of the computer in the car though.
If the Nomadic Pi is going to be mounted in the dash. The GPS device will be surrounded on all sides by steel which is going to hinder your computer getting a GPS fix.
The external GPS antenna I have comes with a 5m lead. So after I install my computer in its final home in the dash. The GPS antenna will be mounted outside the car on the bullbar. With the lead running back through the engine firewall to the computer to avoid interference.
Also beware that the use of an active GPS antenna will slightly increase the overall power consumption of the system.
It's not a great increase but you may run into problems if your computer is running close your power supply is rated at.
Download the image file, write it to an SD card and get started building the perfect entertainment system for your vehicle.
Download Now!