The Pololu A-Star 32U4 Prime is a general-purpose programmable board based on Atmel’s ATmega32U4 AVR microcontroller 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.
The A* Prime supports the on-board microcontroller with many additional features and improvements over competing products, including enhanced connectivity and superior power management. The Prime is available in two main versions: LV, which features a blue solder mask and a step-up/step-down voltage regulator that allows operation from 2.7 V to 11.8 V, and SV, which features a green solder mask and a switching step-down regulator that allows operation from 5 V to 36 V. Each version is available in several different configurations: with or without preinstalled through-hole components like standard Arduino female headers and with or without microSD support. There is also a configuration available for each version with an 8×2 character LCD.
A-Star 32U4 Prime LV (2.7 V to 11.8 V) configurations:
- Item #3105: A-Star 32U4 Prime LV – no microSD support, no preinstalled headers, no LCD
- Item #3106: A-Star 32U4 Prime LV microSD – microSD support, no preinstalled headers, no LCD
- Item #3107: A-Star 32U4 Prime LV – no microSD support, preinstalled headers, no LCD
- Item #3108: A-Star 32U4 Prime LV microSD – microSD support, preinstalled headers, no LCD
- Item #3109: A-Star 32U4 Prime LV microSD with LCD – microSD support, preinstalled headers, LCD
A-Star 32U4 Prime SV (5 V to 36 V) configurations:
- Item #3111: A-Star 32U4 Prime SV – no microSD support, no preinstalled headers, no LCD
- Item #3112: A-Star 32U4 Prime SV microSD – microSD support, no preinstalled headers, no LCD
- Item #3113: A-Star 32U4 Prime SV – no microSD support, preinstalled headers, no LCD
- Item #3114: A-Star 32U4 Prime SV microSD – microSD support, preinstalled headers, no LCD
- Item #3115: A-Star 32U4 Prime SV microSD with LCD – microSD support, preinstalled headers, LCD
We carry an A-Star Prime accessory pack that contains an assortment of parts you might want when assembling the configurations without preinstalled headers (items #3105, #3106, #3111, and #3112).
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.
This product requires a USB A to Micro-B cable (not included) to connect to a computer.
- 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: 2.7 V to 11.8 V
- 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
- 6-pin ISP header for use with an external programmer