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Board recommendation ? - Printable Version

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Board recommendation ? - Lory - 09-14-2025

Hello,

I have 8 wooden doors and I want to install a 12v electric lock in each one and also a NFC card reader in each one.

To power the electric locks I can use a kincony board with 8 relays, but each card reader needs to be connected via SPI or with I2C

Is there a kincony board that can resolve this needs?

Edit:
problem is that the card readers might have the same I2C address, probably I do need a I2C multiplexor TCA9548A?

Also, if I want to use Kincony F series I see that the I2C port is utilized by a LCD screen… how can I overcome this difficulty?

Thanks

RE: Board recommendation ? - admin - 09-15-2025

kincony board have i2c extender on PCB. multi devices can use by same i2c bus, because they are different i2c address.
if you use by esphome, esphome support your NFC reader, it's no problem work with F series board.

RE: Board recommendation ? - Lory - 09-15-2025

(09-15-2025, 12:00 AM)admin Wrote: kincony board have i2c extender on PCB. multi devices can use by same i2c bus, because they are different i2c address.
if you use by esphome, esphome support your NFC reader, it's no problem work with F series board.

Thanks for support,

So, to summarize my understanding:
  1. My problem is that my 8 identical NFC readers might have the same I2C address (probably I2C address hardcoded in their firmware), causing a bus conflict.
  2. The solution is to use an "I2C extender," which is an I2C multiplexer that separates the readers into different channels. Is his "extender" on the Kincony board itself?
Does the board have an integrated multiplexer chip already on the PCB that I can connect my readers to directly? Or, is it simply a set of header pins for the standard I2C bus, meaning I would still need to buy and connect an external multiplexer board (like the TCA9548A)?

Also, if the default I2C port is used by the LCD on the F-Series, could you tell me if there is another port unused which I can use to for the I2C connection?

RE: Board recommendation ? - admin - 09-16-2025

sorry, no multiplexer chip on pcb. But you can define second i2c bus using free gpios.
if you want use multiplexer chip, you can connect with PCB's free gpio.