3 ms·
I saw an NFC chip that has 512 bytes of eeprom. Talks to a micro via I2C and has an interrupt that can be used to wake it up. I think it's a M24LR04E. Costs l
by Gibbon1 2y ago
I saw an NFC chip that has 512 bytes of eeprom. Talks to a micro via I2C and has an interrupt that can be used to wake it up.
I think it's a M24LR04E.
Costs like $0.50.
I think these could be useful for devices where you have a limited amount of data you want to read or transfer. Like why have bluetooth and all the crap that entails when all you want to do is configure a device once.
Advantage of a separate IC is you can use it with whatever microcontroller development stack you have working.
- crote 2y agoThe problem is that it is simply a dual-interface EEPROM. It only holds data, it doesn't process it. Great for something like a device whose configuration you can update via NFC tap (think e-paper display), not so great if you want to do a whole challenge-response dance between microcontroller and NFC smartphone.
- hlandau 2y agoSee comment below. More generally what I'm seeking is something in the card form factor which is suitable to store cryptographic secrets (i.e., a smartcard). Separate IC is a disadvantage here since it creates a vulnerable security boundary and makes it infeasible to integrate the chip into a thin card.