Commercial 1090ES ADS-B in products cost $1000 or more. By cleverly using the Raspberry Pi mini-PC, off-the shelf hardware and free open source software, you can build your own for a fraction of the cost. We call it ... ADS-Pi!
Of course, like any portable ADS-B device, ADS-Pi is not certified. It is experimental and of assistance to situational awareness only. It is not a collision avoidance tool.
Get the "B+" model that has the two USB ports you will need. There are various kinds of cases you can choose from.
Element 14 is a good place to get them.
Get a fast, quality one that's actually 8GB so our image will fit. Or get a 12 or 16GB one to make sure.
Get them from just about anywhere online or at a retail store.
No 12V socket in your aircraft? Use a standard USB battery.
This is the magic bit. These TV receivers can tune to 1090MHz and using a software defined radio decode ADS-B traffic.
This little one from DX works well.
The Pi will be close to your iPad, so a tiny one without external antenna will do fine.
Again DX.com has one that works well.
The same cable as used by many phones (just not ones that run OzRunways) can power your ADS-Pi from 240V or 12V Adapter.
You can simply order some cables with your Pi from Element 14 and use any USB power adapter.
You can download our Linux image for Raspberry Pi B+ (2 GB, unzips to 8 GB) here and unzip the file.
You can download our Linux image for Raspberry Pi 2 (2 GB, unzips to 8 GB) here and unzip the file.
You can download our Linux image for Raspberry Pi 3 (474 MB, unzips to 1.5 GB) here and unzip the file.
Now just stick in your SD card, WiFi adapter and TV receiver, and plug in the power. Withing a few minutes of the "activity" light blinking on the Pi, you should be able to see the "ads-pi" WiFi hotspot.