On December 12, 2014 at 09:37, highfigh said...
RFID.
Sounds like someone's been watching CSI without thinking things through. You know, the TV show where, for several seasons, when they were looking at computer screens to read information, the info on the computer screen was actually projected onto their faces and bodies for dramatic, and technically knee-slapping laughable, effect.
The quotes below are from various places at
[Link: electronics.howstuffworks.com]Data stored within an RFID tag's microchip waits to be read.
The tag's antenna receives electromagnetic energy from an RFID reader's antenna.
Using power from its internal battery or power harvested from the reader's electromagnetic field, the tag sends radio waves back to the reader.
The reader picks up the tag's radio waves and interprets the frequencies as meaningful data.
That is, when Mario wants to know where his nail gun is, he turns on his reader, which sends out a signal to all the RFID chips in the world.
Passive RFID tags rely entirely on the reader as their power source.
Well, that's out unless the nail gun happens to be within a few feet, maybe a few inches, of his scanner.
Regarding active tags:
Because these tags contain more hardware than passive RFID tags, they are more expensive. Active and semi-passive tags are reserved for costly items that are read over greater distances -- they broadcast high frequencies from 850 to 950 MHz that can be read 100 feet (30.5 meters) or more away. If it is necessary to read the tags from even farther away, additional batteries can boost a tag's range to over 300 feet (100 meters) [source: RFID Journal].
So ultimately the guy with the nail gun has to have left the nail gun within about a hundred feet, perhaps 300 feet in the future.
The article says passive RFIDs cost between a nickel and twenty cents, and the RFID's goal is a five cent chip; the article doesn't even take a wild stab at the price of an active unit. That tells me they are now so expensive that the article doesn't want to risk turning off a potential user by revealing today's price.
So for the present, and probably forever, you've got to give up the idea promoted by TV shows that if your dog is stolen from you in Chicago, doing some kind of RFID search is going to make him light up in New Orleans, instantly revealing his location. They don't even want to talk about a hundred feet of range.
On December 12, 2014 at 09:37, highfigh said...
You could use voice messages and then transcribe them later.
This could work but has the same drawbacks as notes or computer files PLUS the added step of transcribing the message.
Thanks, though. I know a lot more about RFIDs than I did a few minutes ago!
