Arduino/Atmel boards aren’t the only Arduino API compatible devices on the market.
80 MHz operating speed
Four SPI and five I2C connectors
16 channel 10-bit ADC, five compare/PWM outputs
Dual CAN controllers
83 available I/O pins
3.3V operating voltage
16 analog inputs
Connects to a PC using a USB A to mini-B cable (not included)
USB 2.0 OTG controller
10/100 Ethernet MAC
Programmable with MPIDE
Also programmable with MPLAB IDE (with the addition of the PICkit3 in-system programmer/debugger)
The PIC32 microcontroller operates at 3.3V. The original Arduino boards operate at 5V, as do many Arduino shields.
There are two issues to consider when dealing with 5V compatibility for 3.3V logic. The first is protection of 3.3V inputs from damage caused by 5V signals. The second is whether the 3.3V output is high enough to be recognized as a logic high value by a 5V input.
The digital I/O pins on the PIC32 microcontroller are 5V tolerant. The analog capable I/O pins are not 5V tolerant. To provide 5V tolerance on those pins, the Max32 contains clamp diodes and current-limiting resistors to protect them from 5V input voltages.