Arduino's MKRZero brings users the power of a Zero in the smaller format established by the MKR form factor. The MKRZero board is a great educational tool for learning about 32bit application development. It has an onboard SD connector with dedicated SPIs that allows users to interact with music files using the Arduino Sound library and I2S library with no extra hardware.
The board is powered by Microchip�s SAM D21 MCU which features a 32bit Arm� Cortex� M0+ core operating at 3.3 V logic levels. The board contains everything needed to support the microcontroller; simply connect it to a computer with a microUSB 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 and the board includes charge circuitry to easily recharge the LiPo from a 5 V source.