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Gyroscopes don't have to spin. MEMS gyroscopes vibrate instead. They do have moving parts, but the moving parts are insanely tiny, fabricated on silicon chips, and packaged in standard microchip packages. Quite amazing, really, when you think about it.

I recently had a perfectly good set of RAM degrade to useless in
only 3 months here

This could caused by contact failure, especially if tin/lead
contacts are mixed with gold connectors. Any electrical contact is subject to
fretting corrosion that eventually makes the contact unreliable.

Here are some articles showing why fretting corrosion occurs and
what to do about it:

http://www.chemassociates.com/products/findett/PPEs_Swedish_Cell.pdf

http://www.nyelubricants.com/lubenotes/LN_Sta_Sep_Elec-04-2.pdf

http://archives.sensorsmag.com/articles/0500/78/main.shtml

http://eprints.soton.ac.uk/51024/01/Final_Tribology_paperJMcB__(A).pdf

An old radio engineer's trick from the 1930's is to coat the contact
with ordinary vaseline. It is a hydrocarbon and cleans the grime and
oxides from the surface allowing a true metal-to-metal contact. This
reduces the contact resistance by a factor of ten and stabilizes it.

The vaseline leaves a film that lubricates the contact and
eliminates the fretting corrosion. It works on memory cards, power
connections, SATA connectors, pcb contact fingers, and any other
connector in the PC.

For more information, please see my post on mysteryonion's page on
solving Kenmore front load washer fault codes at

http://www.flickr.com/photos/mysteryonionpatch/471156850

To find it, search for "monettsys". It is dated Wed Feb 25, 2009,
11:58:03 pm, near the bottom of the page.

Regards,

Mike Monett

See Making Ethernet Work in Real Time, from Sensors magazine. They show how to calculate the odds of delay exceeding a given value for a given network speed and loading. With a 10 Mb Ethernet, sending 1000 64-byte packets per second, you can be 99% sure there will not be a delay of more than 7 ms in 9 years. You can't load the network very much (5-10% is tops for a real time application). But the odds of an error are higher than the odds of a timing miss.

CANbus latency is only deterministic for the highest priority messages on the cable. Everything else is subject to nondeterministic delays due to preemption.

It's all data, no action. You can query the 'fridge, but you can't order food and have it show up in the fridge. Combine Webvan with a pass-through refrigerator the delivery service can access, and you'd have something. Maybe even within-building robotic delivery, which would work for apartment blocks.

There's no automated cleaning. iRobot's Roomba vacuum is a joke, but there are units around $2000 that almost work. Get those into production. An apartment that cleans itself while you're out would actually be useful.

The computer-in-the-fridge thing and the control-via-power-outlet thing have been done to death over the last decade. They're just not that useful.

The big thing in building control today is Demand Control Ventilation. Instead of thermostats, you have little sensor boxes that sense temperature, humidity, CO2, CO, and air pressure. Crunching on that data, the HVAC system works to maintain a comfortable environment at minimum cost. When CO2 is no higher than outdoor ambient, the room is empty and airflow can be cut way down. When the number of people in the room increases, the higher CO2, temperature, and humidity readings cause the HVAC system to be cranked up accordingly. Of course, you also have a sensor at the outside air intake, so the system knows when to use outside air and when to recirculate. There's also the little trick of watching the air pressure as the fan speed changes. If the indoor air pressure doesn't change with fan speed, there's a door or window open, and the HVAC system shouldn't try too hard to fight that.

http://www.sensorsmag.com/ is often a good starting point for sources of this type of technology.

Some manufactures of modules are http://www.napion.com/ and http://irtec.com/ . MuRata makes the IRA-E700, Global makes the RE200B and good ol' Hotek makes a controller for the sensors, HT761X.

Here is the NEMA spec for motion sensing http://www.nema.org/stds/wd7.cfm

I don't think any GPS receivers record or store that. Until I started looking, I wasn't even sure how you would measure something like that, without moving mechanical parts. There are magnetic compass sensors and solid-state MEMS accelerometers, but none of them do the trick.

I did some Googling and it would seem that there are things called "tilt sensors" or "electrolytic inclinometers" that would probably do the trick if you were wanting to. They use fluid-filled capsules, almost like a mercury switch but with more resolution. (More info here.) I've certainly never heard of a GPS instrument with them built in, but that doesn't mean it doesn't exist.

The only applications I can think of where you'd want to combine something like that with a GPS would be in aircraft navigation, or perhaps some very special remote-control/robotics systems (*cough* cruise missiles *cough*). Nothing that you're going to find for a few hundred bucks at WalMart, I'd guess.

But as the idea of geotagging photos becomes more mainstream, I think we can plan on seeing a lot more interesting hardware applications of GPS. After all, the camera manufacturers need to find some way to get folks to upgrade -- once everybody has a 4 or 6MP camera, the upgrade cycle that's been driving the market for the last few years (more pixels) is effectively over. The difference between a 6MP and an 8MP camera, or between 8 and 10, is small to the layman who doesn't do more than the very slight cropping to his photos -- and even more irrelevant if it doesn't come with prohibitively expensive optics.

It's electronics and integration -- cellular integration, WiFi, GPS -- that are going to be big features in the next round of cameras; that's if convergence devices don't kill them off first (I don't think they will, but we'll see).

By "looking at it." Remember, temperature is just a measure of the kinetic energy of matter. You don't have to make physical contact with something to determine it's energy. Jumping in front of a car might be one way to find out how fast it's going, but it's not the only way.

You can infer the temperature of an object by the amount and wavelength of the electromagnetic radiation emitted by the object. Although this is obvious for very hot objects that are incandescent (at temperatures >1000C), it is also true for any object with a temperature greater than absolute zero. A very cold object will, of course, radiate much less energy than a hot one; total radiation per unit area is proportional to the fourth power of temperature. -http://www.sensorsmag.com/articles/0900/17/main.s html

Most of the common methods for industrial temperature measurement are listed on that page as well.

Mesh networks offer the possability of having each node pass a note to the node closest to them in the direction of the node they are trying to reach. They only have to speak loud enough for that closest node to hear, making meshes a lot more scalable. Like passing notes in high school rather than shouting across the room and getting the teacher pissed off at you. :) I suspect that as wireless devices become more popular we'll need something like mesh networks to make more efficient use of the spectrum. In fact, in a manner similar to Bittorrent and Freenet, the more people that participate in a mesh network, the more resiliant and speedy the whole network is.

sb