Maybe someone has another idea to get them working. I have just one card-sized transponder and 4 small tags from 2 different shops. All with the same frequency and technology etc... but just the card works.
Are you sure they use the same protocol? there are different handshakes and different frequencies and RFID is not that compatible. - see Radio-frequency identification - Wikipedia - for some details.
If only the coil was smaller it should work on a shorter range, IIRC: Power is a function of EM-flux and EM-flux is a function of the distance (^3?)
you are right in every point.
But: it is all from the same series with the same chip (well, the manual says that) from the same shop (And there are only these so i think they should be compatible....). The chipcard has a very small range so i thought about that it might be too less power for the smaller tags. I´ll see if i can try this on another rfid reader with more power.
I would go to the shop with all the RFID tags bought there and bring back the 'not working ones' and asking for new (try before you buy) - Also a nice way to show off with your Arduino RFID reader
yeah, well, everything is from the pollin webshop and i have send the rfid tag back and got a new one (which doesn't work too...) so i think its a problem of the reader..
well, i have a few solution ways i´ll try in the next days
Even a tag using the same chip will not work in all readers because of the data that is put on the chip. Most of the time this data is arranged so that there is a number of parity bits scattered through the code, on other types of tag there is no parity aligned data.
Now if the reader is expecting this code to contain parity bits and it doesn't see them it assumes it is a miss read and outputs nothing. You must ask your shop if your reader can read both sorts of tags.
okay, i attached a second coil to it and now it works with the smaller rfid tags. So its just a problem of too less range.
I´ll see if i can increase the transmission power
