A low cost single board computer called the Orange Pi PC hit the market a few months ago for a list price of $15 (bare board, no power/microSD/case):
It’s got a quad-core 1.5Ghz ARM7 cpu (Allwinner H3) and 1GB of RAM, so on paper it should give the RPi 2 a serious run for its money. At any rate, I bought one to see if I could use it as a cheap Pi alternative; it shipped very quickly and is a pretty nice board. They don’t support power over the micro USB connector, so I’m using an old Sony PSP 5V 2A adapter I got at Goodwill for $2 and a Samsung 32GB microSDHC card I swiped out of an RPi.
So far, so good. Software support for the Orange Pi boards is pretty spotty, but there’s a Lubuntu Mate disk image that works well. I installed the Flightaware version of dump1090 and the PiAware package, and it seems to be ticking along just fine. Both the Orange Pi and RPi 2 are using ARMv7 processors, so there’s no need to recompile. Dump1090 is using ~25% of one CPU core.
It’s running as Site 15626. I’m using the same super-cheap RTL820T receiver and 69mm whip antenna I was using on my RPi (site 7950). If I get really enthusiastic I’ll try a wifi dongle on it. I’ll probably let it run for a week or two then switch back to my RPi, as I really want to test what this board can do as a bittorrent client or an OpenVPN gateway.