The MKR ZERO is a compact board that utilizes the power of a Zero in the smaller format established by the MKR form factor. It is designed as an educational tool for learning about 32-bit application development and features an onboard SD connector with dedicated SPI interfaces (SPI1) that allows for the use of MUSIC files without any additional hardware. The board is powered by Atmel’s SAMD21 MCU, which features a 32-bit ARM Cortex M0+ core. It should be noted that the board operates at 3.3V, with a maximum voltage tolerance of 3.3V for its I/O pins. Going above this voltage could potentially damage the board. The board includes everything needed to support the microcontroller and can be connected to a computer via a micro-USB cable or powered by a LiPo battery. The battery voltage can also be monitored through a connection to the board’s analog converter. The technical specifications of the board are as follows: Microcontroller: SAMD21 Cortex-M0+ 32bit low power ARM MCU Board Power Supply (USB/VIN): 5V Supported Battery (*): Li-Po single cell, 3.7V, 700mAh minimum DC Current for 3.3V Pin: 600mA DC Current for 5V Pin: 600mA Circuit Operating Voltage: 3.3V Digital I/O Pins: 22 PWM Pins: 12 (0, 1, 2, 3, 4, 5, 6, 7, 8, 10, A3 – or 18 -, A4 -or 19) UART 1 SPI 1 I2C 1 Analog Input Pins 7 (ADC 8/10/12 bit) Analog Output Pins 1 (DAC 10 bit) External Interrupts 10 (0, 1, 4, 5, 6, 7, 8, A1 -or 16-, A2 – or 17) DC Current per I/O Pin 7 mA Flash Memory 256 KB Flash Memory for Bootloader 8 KB SRAM 32 KB EEPROM no Clock Speed 32.768 kHz (RTC), 48 MHz LED_BUILTIN 32 Full-Speed USB Device and embedded Host Warning: Unlike most Arduino & Genuino boards, the MKRZero runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Applying voltages higher than 3.3V to any I/O pin could damage the board.