Sensor Area Networks (SANs)

[nedb]

(05-31-2013 09:56)davidmbrady Wrote:  

(05-30-2013 20:06)nedb Wrote:  Love the coach "Call for help" concept.

I figure we ought to get a rep point when we order XBee radios. Otherwise, I'm just going to order a couple of 'em today. We'll reel this one in, I can feel it.

--Ned

We can definitely work on that Ned - it'd be especially useful to get a break on the gateway. We'll need a WAN and/or a cellular gateway (CDMA or GSM) of sorts and right now that seems to be where the money is. The data plan is cheap and can be purchased on a month by month basis.

For folks interested, google the "internet of things" or "web of things". Imagine dropping your coach off for a prolonged service period. Imagine sitting in your chair at home and browsing the condition of the bus's batteries, or whether it's plugged in, or whether the genny is running, or if the doors are locked. Endless possibilities!

David, you are true blue

I saw James Gosling talking about his vision of the future for the internet. The theme was "ubiquitous everywhere" -- a world where every thing has an address on the internet. It was mid-1990s, the internet had gone commercial and spawned the dotcom boom, and anything was possible! It was like: Imagine you're getting ready for work, you have a handful of shaving lather but there's no hot water. Your shaving mirror is also an information appliance touch screen browser -- you access the water heater, retrieve the parts list, search for a new heating element in stock, anywhere near your route to work, pay for it securely and opt to pick it up in 45 minutes.

Actually, Gosling was much geekier--the example he gave (that I remember) illustrated how ubiquitous everywhere would be: "Your toaster will be on the internet." It was brilliant

Anyway, I hear you.

I haven't looked at truck/trucker data plans or infrastructure. I imagine it is designed primarily for relaying position and maintenance data back to fleet operations, is that what you're talking? Not a lot of bandwidth needed, and I can see how coach data could be that way too. Monitoring doesn't have to involve security cameras. Providers of 'net access to fleet trucks must be focused on big corridors where trucks are, which might not be good coverage for footloose coaches. Too, trucks are moving, so if there's no coverage where they are, they probably will be soon, so they can store data and transmit when possible. Coaches might get better coverage using a MiFi, considering most coaches probably are not stored (or serviced) in sight of the freeway.

What about packet radio. It could switch on every 30 minutes to send a mesh-generated report to the email gateway via repeater. Repeater density might not be that great either, so coverage remains an issue for that idea.

I saw a tiny new 1-wire temperature sensor for a couple of bucks. Each one is encoded with a unique 16-bit identifier. I thought that might make it very simple to poll the SANduino mesh for all temperature readings. The identifier would be a handy way to keep track of sensor locations, data, status, ... There's an encapsulated version too, waterproof. This kind of sensor tech (available with bulk discount, cheap, miniature, data-friendly) gets my juices flowing. If you barbecued Gosling's future vision and pulled it apart for lunch, it would be like a platter of this generation of sensors, cheap enough for deploying in sufficient numbers to give good resolution, minimal wiring requirements, perfect for matching to latest tiny computers, and making it practical to wirelessly (with cole slaw) mesh and report on a complex system like a coach (on a sub roll).

I ordered Series 2 XBee stuff today. I almost got Series 1 for their easy configuration friendliness, but since the 2 series is newer, I figured it is not a bad choice--the Series 1 is not compatible with the Series 2, but future development of compatible stuff will be based on Series 2 requirements. Must be a lot of demand for the Series 1 features, though, they're widely available for sale on the web.

XBee used to use a shield and be pretty much for Arduinos. Now it looks like it has spread via USB ports to all manner of computers. I splurged on a FTDI cable and a Pro series 60 mW radio, along with an affordable 2 mW radio, a shield kit, AVR programmer, ... The shop was offering a free rPi with orders over $350, but I didn't come anywhere near close to that. Maybe once this SANduino mesh prototype takes shape.

Getting the pieces is the easy part, I know. Taking the time to put ideas into the hardware is a little harder. The book will facilitate that part of it, it sounds like it was written for Series 2 XBee projects. It's an O'Reilly publication, at their prices it should be a lay-flat binding and good paper quality! I've forgotten the title, but the author is Faludi. I'll be doing chat at a distance shortly after the package arrives. Fingers crossed

--Ned