The Pololu A-Star 32U4 Prime is a general-purpose programmable board based on the ATmega32U4 AVR microcontroller from Microchip (formerly Atmel) and arranged in the common Arduino form factor exemplified by the Uno R3 and Leonardo. As such, the A-Star Prime (abbreviated A* Prime) is compatible with many Arduino shields, including all of the Arduino shields we carry. All 26 of the microcontroller’s GPIO lines are accessible on the board, including seven than can be used as PWM outputs and twelve that can be used as analog inputs. The ATmega32U4 is capable of native full-speed USB, which makes it more versatile than similar boards that rely on USB-to-serial adapters: in addition to supporting a virtual (CDC) serial/COM port interface, the A-Star can appear to a connected computer as a mouse and keyboard. The A-Star’s USB interface can be accessed through its USB Micro-B connector

Features:

Programmable ATmega32U4 MCU with 32 KB flash, 2.5 KB SRAM, 1 KB EEPROM, and native full-speed USB (clocked by precision 16 MHz crystal oscillator)
Preloaded with Arduino-compatible bootloader (no external programmer required)
All 26 general-purpose I/O lines from the ATmega32U4 are broken out (including PB0, PD5, and PE2); 7 of these can be used as hardware PWM outputs and 12 of these can be used as analog inputs
Convenient 0.1″-spaced power, ground, and signal connection points
Buzzer option for simple sounds and music
microSD support (microSD version only)
HD44780-based character LCD option
3 user-controllable LEDs
3 user pushbuttons
Reset button
Power features:
- Can be powered from USB or from an external source (with several access points for connecting external power)
  - LV operating range: 2 V to 16 V (Note: it requires an input voltage of at least 3 V to start, but it can operate down to 2 V after startup)
  - SV operating range: 5 V to 36 V
- Switching 5 V regulator enables efficient operation
- 3.3 V rail supplied by 300 mA linear regulator
- Power switch for external power inputs
- Reverse-voltage protection on external power inputs
- Power selection circuit allows for seamless switching between power sources while providing overcurrent protection, and feedback about which power source is selected
Comprehensive user’s guide

Specifications:

3114: A-Star 32U4 Prime SV microSD – microSD support, preinstalled headers, no LCD
3115: A-Star 32U4 Prime SV microSD with LCD – microSD support, preinstalled headers, LCD

Documents:

Warranty:

Warranty will not apply if Product fails or is damaged after delivery to you due to accident, abuse or misuse.

Package Includes:

1 x Pololu 3114 / 3115 A-Star 32U4 Prime SV microSD

Processor Specifications
Processor	ATmega32U4 MCU
Memory Specifications
RAM	2560 bytes
Flash	32 KB
Electrical Specifications
Minimum Operating Voltage	5V
Maximum Operating Voltage	36V
Additional Information
Warranty