grid of sensor to detect presence of tags

[oferrer]

Hello everyone,

I need a matrix of positions representing where some rfid tokens (2cm x 2cm tiles) are on a surface (aprox 70cmx70cm). I need detect any variation on this matrix.

Tokens have ICODE SLIX chip inside. (In their main use they are read by a PN5180 in iso15693 config)

The speed of reading the grid is ​​more important than the accuracy of the position. The surface could be divided into areas, and the only thing that matters is knowing which area a token was placed on. It should be noted that there may be several pieces on the surface.

Any suggestions for sensor to use.

Thanks in advance

[EduardoZamora]

Hello @oferrer,

Hope you are doing well.

When working with an NFC reader, you may just know if the tag is within the working range of the reader or not; the distance between them is usually not measurable since the reader transmits the carrier itself while the card/tag just "loads" the field.

If you are planning to use an antenna multiplexing concept, unfortunately there is not so much information I could recommend besides the proof of concept mentioned in Starting a product development with CLRC663 plus family, Section 3.2.

When several tags are present in the field, they can be handled by the Anti-collision procedure defined by ISO 15693 specification.

Regards,
Eduardo.

[oferrer]

Hello @EduardoZamora,

Thank you for your reply,

Yes, I'm keeping the states of a game. In player area tiles are inventoried (NXP custom fast inventory read slot16 iso15693 command is implemented) by PN5180 devices and position there is not relevant.

The problem is when players move tiles into the play areas,, which are not so few that I don't have to worry about the number of additional PN5180 readers.

I have one esp32 controller serving each player and I have another for the playing surface, which will control what I decide to use to determine which areas on the surfaces the tiles went to.

And yes, I was thinking about multiplexing, but I need to reduce costs. I don't know if multiplexing the RFID antennas is feasible, instead of multiplexing multiple pn5180 SPI connections. Readers (PN5180+Antenna) were customized.

I will check the suggested link to see if it works for what I need. Any other suggestions will be welcome.

Best regards,

Osmany