Hello,
We want to implement the new ST25100 or ST25R200 in our project. There we need to have 8 RFID antennae to read and write to 8 NFC Tags as fast as possible. The NFC Tags will be placed on a drawer, so all 8 Tags are in the range of the antennae at the same time.
We already did a prototype 1 years ago with ST25R95 (CR95HF). There we had one stm microcontroller and 8 ST25R95 connected by the same SPI. The used RFAL firmare has only one instance of ST25R95 and we had to startup and initialize every chip one by one to read out the tags. This setup needs time to start every chip and reading the tag. At problems with initializing, resetting this chip was very bad, but the new chips have a reset line.
The 8 RFID antennae and ST25R95 have a distance of 80mm next to each other, so we have a large distance from the first to last chip and antennae.
The antenna is not an integrated PCB antenna. Every antenna is connected by a 200mm cable to the PCB.
My question now is what will be the better way to implement this with the new ST25R100/200? Is it a better approach to multiplex 8 antennae with one ST25R100 (AN6121) or to have 8 ST25R100/200 connected parallel (SPI) to one stm microcontroller? We have the pins to use SPI (8 CSN lines) so we don't use I2C.
I don't know, if multiplexing antennae at this distances is possible or even a good idea.
Also considering the firmware, what would be the faster way to read all 8 tags, by multiplexing antennae or with separated chips for each tag?
Does anyone have any suggestions?
Thanks a lot.
