4 ms·

The NFC chip I want still doesn't exist: a CPU and flash I can write a program for, directly, no VMs, no Java, without an NDA'd datasheet. These exist, but the

The NFC chip I want still doesn't exist: a CPU and flash I can write a program for, directly, no VMs, no Java, without an NDA'd datasheet. These exist, but they're all behind NDAs and you're not allowed to have them. They're used for e.g. EMV.

userbinator 2y ago
How about something like this: https://hackaday.com/2009/06/27/avr-rfid-tag/ https://hackaday.com/2009/06/27/avr-rfid-tag/
bsder 2y ago
Is there a problem with the TI NFC chips? They all seem to be purchasable and have available datasheets.
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 ago
  The 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 ago
  See 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.
G4E 2y ago
You should check out the lpc8N04 from NXP then ;)
- hlandau 2y ago
  This is interesting but clearly not intended for security/cryptographic applications... no security hardening, no hardware cryptography, and it's also not available in a card form factor according to the datasheet.

userbinator 2y ago

How about something like this: https://hackaday.com/2009/06/27/avr-rfid-tag/ https://hackaday.com/2009/06/27/avr-rfid-tag/

bsder 2y ago

Is there a problem with the TI NFC chips? They all seem to be purchasable and have available datasheets.

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 ago
The 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 ago
See 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.

G4E 2y ago

You should check out the lpc8N04 from NXP then ;)

hlandau 2y ago
This is interesting but clearly not intended for security/cryptographic applications... no security hardening, no hardware cryptography, and it's also not available in a card form factor according to the datasheet.