Post by thread:[OT:] active RFID?

Hello, does anyone know if is that possible to use something such as an "active rfid tag" that when is readed it reads data from a sensor and informs the reader? if not, maybe rfPIC? What i want is to put temp sensors in several places, that will not have a battery and it will be read contaclessly by some kind of radio. []s Rafael. ____________________________________________

On Tue, 19 Oct 2004 09:52:06 -0200, you wrote: > > Hello, > > does anyone know if is that possible to use something such as an >"active rfid tag" that when is readed it reads data from a sensor and >informs the reader? > > if not, maybe rfPIC? What i want is to put temp sensors in several >places, that will not have a battery and it will be read contaclessly >by some kind of radio. No reason in principle why this isn't possible - I don't know if any current RFID chips have external interfaces though. Ought to be do-able with a 12f675 and a thermistor - main issue is range and getting enough power to it. ____________________________________________

> > does anyone know if is that possible to use something such as an > >"active rfid tag" that when is readed it reads data from a sensor and > >informs the reader? > > > > if not, maybe rfPIC? What i want is to put temp sensors in several > >places, that will not have a battery and it will be read contaclessly > >by some kind of radio. > > No reason in principle why this isn't possible - I don't know if any current RFID chips have > external interfaces though. > Ought to be do-able with a 12f675 and a thermistor - main issue is range and getting enough power to > it. Do you want a distributed network that reports back, or are you looking for sensors that a person with a handheld unit can go check? Anything with a distributed network, where the sensors are expected to broadcast over any reasonable distance (more than a few cm or tens of cm) is probably going to require some sort of local power source. It can be a small power source (button cell battery or maybe a solar cell), but it will probably require one. Mike H. ____________________________________________