| MCU | Tested Works | Doesn't Work | Not Tested | Notes |
|---|---|---|---|---|
| Atmega328 @ 16MHz | X | SPI & I2C Works | ||
| Atmega328 @ 12MHz | X | SPI & I2C Works | ||
| Atmega32u4 @ 16MHz | X | Follow instructions at https://learn.adafruit.com/adafruit-pn532-rfid-nfc/shield-wiring#using-with-the-arduino-leonardo-and-yun to move pin 2. | ||
| Atmega32u4 @ 8MHz | X | SPI & I2C Works | ||
| ESP8266 | X | SPI only, I2C clock stretching not supported | ||
| Atmega2560 @ 16MHz | X | SPI & I2C Works | ||
| ATSAM3X8E | X | SPI & I2C Works | ||
| ATSAM21D | X | SPI only, I2C clock stretching not supported. Use programming port. | ||
| ATtiny85 @ 16MHz | X | |||
| ATtiny85 @ 8MHz | X |
- ATmega328 @ 16MHz : Arduino UNO, Adafruit Pro Trinket 5V, Adafruit Metro 328, Adafruit Metro Mini
- ATmega328 @ 12MHz : Adafruit Pro Trinket 3V
- ATmega32u4 @ 16MHz : Arduino Leonardo, Arduino Micro, Arduino Yun, Teensy 2.0
- ATmega32u4 @ 8MHz : Adafruit Flora, Bluefruit Micro
- ESP8266 : Adafruit Huzzah
- ATmega2560 @ 16MHz : Arduino Mega
- ATSAM3X8E : Arduino Due
- ATSAM21D : Arduino Zero, M0 Pro
- ATtiny85 @ 16MHz : Adafruit Trinket 5V
- ATtiny85 @ 8MHz : Adafruit Gemma, Arduino Gemma, Adafruit Trinket 3V