<r>I bought a random GPS dongle for $20 on Amazon; it's a GD-1201.<br/> <br/> Works fine on Ubuntu 12.04.<br/> <br/> When my Pi arrived, I installed debian6-13-04-2012.zip on an SD card, booted it up, and followed the tips at <URL url="http://catb.org/gpsd/troublesh.....oting.html">http://catb.org/g...

I ordered a http://www.amazon.com/x/dp/B004B9ZK4M/, and it does power the pi just fine for the half-hour I tried it.  I'll report on battery life once I get a chance to test it.

All the batteries I pointed to have 5v USB out jacks, so they already have regulators built in, I think.

<r>Here are another couple external-ish batteries with USB out that seem like good possibilities:<br/> <br/> <URL url="http://www.amazon.com/x/dp/B004B9ZK4M/">http://www.amazon.com/x/dp/B004B9ZK4M/</URL> 4xAA (2000mAh), $19<br/> <br/> <URL url="http://www.adorama.com/BYSOCPELS.html">http://www.adora...

<t>mental2k said: <br/> <br/> <br/> Maybe slightly off topic, but would using a serial GPS module be surer choice?  Its what I plan to do just to educate myself on the matter but still the UART communicaton should be standard right?<br/> <br/> <br/> USB works fine.  The only problem with it is the t...

The gpsd that comes with the debian image, 2.95, is very old and doesn't support my dongle.  Ubuntu 12.04 comes with version 3.4 and works with my dongle.  I guess I'll try building that... or maybe I'll try the Fedora image, it may be more up to date.

<t>I think the way to go is to let ntpd talk to gpsd, and ask the system for time.<br/> <br/> Then to get position, run gpspipe -w and parse its output.<br/> <br/> Here's the incredibly crappy way I did that in a mix of C and shell: FILE *fgps;<br/> fgps = popen("gpspipe -w -n 5 | \<br/> tr , '12' |...

<r>Another option, if you like AA cells, is <URL url="http://www.amazon.com/x/dp/B004B9ZK4M/">http://www.amazon.com/x/dp/B004B9ZK4M/</URL><br/> <br/> It's a lot cheaper, but only lasts a quarter as long.<br/> <br/> I'm still looking for the best battery solution, but maybe I'll go with this one for ...