Monthly Archives: August 2013

Raspberry Pi – low powered computing fun!

I have been playing around with my Raspberry Pi for a while here, my original plan was to use it as the high level control for a Arduino based repeater controller (handling the low level repeater stuff (timers, CWID, etc.), but I had my home Windows based server die on me and I needed something to update the CWOP network with my weather station data.   The server I had was a Windows 2003 server running on an old T42 IBM Thinkpad with an external USB drive. It died a somewhat noisy death as the CPU cooling fan finally seized (made an awful racket for about 24 hours before giving up the ghost).  I had performed surgery once before to replace the fan, but as I didn’t really need a full Windows server to perform a simple web update every 8 minutes, and I also have a 1TB LG-NAS device to act as a file server – so why have this power hungry machine to perform this simple task?  Enter the Raspberry Pi…

I found a post about using PHP on the Raspberry Pi to update the CWOP network from data collected from a Peet Bros U800 – I was using a Peet Bros U2100, so I figured I’d give it a try.
I made a few changes as the wind speed was being reported in kph, not mph, the humidity was being reported incorrectly at 100% (needs to report “00”), and I set it up to report local time.  Success!  The RasPi was now uploading my WX reports to CWOP every 8 minutes and taking a fraction of the power. It’s a low powered machine on 2 levels – doesn’t draw much current (about 2.5W), but it’s not a high performance workstation either.  But it’s perfect for this application – no need to tie up a power hungry computer 7/24 to perform a simple task.

Since this is barely using the RasPi capabilities, I am playing around with other tasks it can perform – currently it’s also hosting an inexpensive SDR module (Realtek RTL2832U based USB TV tuner) to receive some local FM data and decode it.  I am still not 100% on the legality here (it’s public safety POCSAG pages) – I need to clear this up before I take it much further. I am a subscriber to this paging system as a firefighter, and I have an application in mind (fire station paging “receiver”), so I am a legitimate user – but I still want to make sure this is OK.

More on how to do this can be found here.