I've been playing with some inexpensive sensors that you can hook up to a Raspberry Pi computer this past week. I have a "Triple Axis Accelerometer/Magnetometer (Compass)" sensor and a "Barometer/Temp/Altimeter" sensor. You can also get a GPS sensor but I haven't ponied up for that yet.

These little "breakout boards" are really pretty amazing, both of them are about the size of a postage stamp and only a bit thicker than cardboard. The Raspberry Pi computer can almost fit inside an Altoids tin, and there'd be a lot of airspace inside it, so all this is pretty small and light.

I've also been working on a "graphic user interface" or "GUI" so you can visualize all this data, so what I'm pretty close to making at this point is pretty much a home made GPS.

Here's what I want to do that's a bit different, so I'm going to run it by all of you because I think I may be on to something useful.

The RPi (Raspberry Pi) computer is about as powerful as your standard smart phone or high en GPS, and we all know the pros and cons of both those. Two of the most prominent are the phone has a sucky battery life and GPS has a sucky screen, and on the plus side the GPS has a pretty good battery life and the Phone has a pretty good screen.

The RPi has pros and cons too. It doesn't have a built-in screen at all, or a GPS, but you can hook up a really big screen to it, and you can add on a really good GPS sensor.

I think what I can do with a RPi is make a GPS with all the other important bells and whistles that will last a really long time on a couple AA batteries, but it won't have a screen at all. Instead, you'll use Bluetooth to access the data on it with your smart phone. When you're not looking at it you turn your phone off, but the RPi will stay on and continue to collect data and create a track while you're hiking.

One of the really cool advantages to this set up is that everyone hiking with you can use their phone to access the data too. You can all look at the same map, same waypoints, same compass, altimeter, etc. at the same time on your own phones.

If someone else is also carrying one of these RPis you can all look at theirs too. You do this by using the web browser on your smart phone, so no one has to install any apps or anything at all. They just have to connect to the Bluetooth on the RPi and type in a short URL in their web browser and they've got a full blown GPS app up and running.

Once you are connected you can all upload photos to the RPi and you can all view and share them with each other, and download and save them and your GPS track and other data onto your own phone. Same with videos, you just need to be within 10-30 meters of the RPi to connect to it with your phone and share stuff.

Even if your hiking solo, and never turn on your phone, this device could be attached to your pack and collect data for you. You could even attach it on top and outside of your pack where it will get the best reception and not worry about it because there's no screen to bust up and you can get cases that are tough as can be.

When you get home you can all transfer the GPS data from either your phone or the RPi to your favorite Desktop computer mapping app just like you would from the GPS you use now.

Finally, using these two devices, the phone and Rpi-GPS, together like this should help extend the battery life of both devices. The Bluetooth connection is the lowest power connection you can use on your phone. You don't need cell service or wifi even turned on in your phone to use it with the RPi, and it won't really use any more power on the RPi if more people are connected to it.

What do you think?