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 3.3 V to any I/O pin could damage the board.
The board contains everything needed to support the microcontroller; simply connect it to a computer with a micro-USB cable or power it by a LiPo battery. The battery voltage can also be monitored since a connection between the battery and the analog converter of the board exists.
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: 9 (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: 321
Full-Speed USB Device and embedded Host.