Expansions Arduino UNO headers with Pins 14x digital I/Os 13x LED pins Analog – 6x analog input pin, 2x 12-bit analog DAC 6x PWM 1x UART, 1x I2C, 1x SPI CAN Bus support I/O Voltage – 5V and 3.3V (Not available on Arduino boards, but works on Waveshare board – TBC) I/O current – 8 mA R7FA4 PLUS B only Qwiic I2C connector for expansion modules. Both the Waveshare R7FA4 Plus A and B boards are functionally equivalent to the Arduino UNO R4 Minima and WiFi boards, except for the additional support for 3.3V Arduino shields (on top of 5V ones) and the extra power output header.