The NFC/RFID Shield is tested and fully compatible with the following boards:
- Arduino Uno (all revisions)
Arduino Mega 2560 R3 (not R2 or earlier, see below)
- Arduino Mega ADK
- Arduino Duemilanove and Diecimila w/ATmega328 chip
- Arduino Due (with latest library)
This shield may work with other boards with some additional steps:
- Add jumper wire from SDA on shield to pin 20 on Mega board.
- Add jumper wire from SCL on shield to pin 21 on Mega board.
- Cut trace between IRQ and pin 2 on shield.
- Add a jumper wire from IRQ to a different pin (not 2 or 3), e.g. pin 6.
- Modify the Arduino sketch to reference the new IRQ pin number.
The shield uses the following pins:
- Digital pin 2 (except w/Leonardo modification described above)
- SDA and SCL (on boards that have these pins)
- Analog pins 4 and 5 (see notes below)
Do not use Analog pins 4 or 5 with your project in combination with this shield, even on Arduino boards that use different pins for I²C communication (Leonardo, Mega, Due). For compatibility with “classic” (pre-R3) Arduino boards, the shield connects SDA and SCL to Analog pins 4 and 5, respectively; communication and analog readings would mutually interfere. Leonardo users should likewise avoid Digital pins 2 and 3 when using I²C.
Arduino Mega 1280: compatibility is likely similar to the Mega 2560 R2; extra jumper wires would be required as explained above for that board, but the shape may make that difficult.
- Adafruit Menta: equivalent to Arduino Duemilanove w/328 chip; almost certainly compatible. However, the shape of the shield will require removing the board from its tin.
Arduino Duemilanove and Diecimila w/ATmega168 chip: electrically and mechanically compatible with 328 chip, but has only half the RAM and program space. The library is not especially memory hungry, so this is very likely compatible but not 100% assured.
- Arduino NG or older: possibly compatible, memory constraints permitting.
If experiencing trouble with a board listed as “compatible,” review the introduction for tips and visit the Adafruit Forums for assistance.