The A-Star 32U4 Mini ULV is a programmable module based on the ATmega32U4 from Microchip (formerly Atmel). Unlike competing products, it has an on-board switching step-up regulator that allows it to be powered efficiently from a 0.5 V to 5.5 V supply. This compact 1.9″ × 0.7″ board breaks out all 26 of the microcontroller’s I/O pins (of which 7 can be used as PWM outputs and 12 as analog inputs), and loading programs is made easier by a Micro-USB interface and a preloaded Arduino-compatible bootloader.
The Pololu A-Star 32U4 Mini boards are general-purpose programmable modules based on the ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), which has 32 KB of flash program memory, 2.5 KB of RAM, and built-in USB functionality. The A-Star (abbreviated A*) adds a number of onboard features to support the microcontroller and make it easier to work with, including a 16 MHz crystal, a USB Micro-B connector, an in-system programming (ISP) header, a reset button, and three indicator LEDs.
Each A-Star 32U4 Mini contains a switching regulator that efficiently produces 5 V from an external voltage source to power the microcontroller. Three different versions are available, covering a wide range of input voltages:
- A-Star 32U4 Mini ULV: 0.5 V to 5.5 V
- A-Star 32U4 Mini LV: 2.7 V to 11.8 V
- A-Star 32U4 Mini SV: 5 V to 40 V
A robust power selection circuit enables seamless transitions between regulator power and USB power, and overcurrent and reverse-voltage protection help safeguard the board against accidental damage.
All 26 general-purpose I/O lines on the ATmega32U4 are accessible on the A* 32U4 Mini; 7 of these are usable as PWM outputs and 12 are usable as analog inputs. The board measures 1.9″ × 0.7″, the same size as an Arduino Micro, and features a pair of mounting holes sized for #2 or M2 screws (not included). Its 0.1″ pin spacing makes the A* easy to use with solderless breadboards, perfboards, and 0.1″-pitch connectors.
Our comprehensive user’s guide provides the basics you need to get started with the A-Star as well as detailed technical information for advanced users.
More technical information at Pololu.