The A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge is a programmable module well-suited for robotics applications, designed to work either as an auxiliary controller mounted to a Raspberry Pi or as a standalone control solution for a small robot. This A-Star (abbreviated A*) is based on the ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), which has built-in USB functionality, and it ships with a preloaded Arduino-compatible bootloader. Its complement of peripheral hardware includes dual motor drivers capable of delivering a continuous 1.8 A per channel, along with pushbuttons, LEDs, and an optional buzzer for building a user interface. An efficient switching voltage regulator allows the controller to work over a wide range of input voltages (2.7 V to 11 V). The robot controller board conforms to the Raspberry Pi HAT specification, allowing it to be used as an add-on for a Raspberry Pi with a 40-pin GPIO header (Model B+ or newer, including Pi 3 Model B+ and Model A+) . On-board level shifters make it easy to set up I²C communication and interface other signals between the two controllers, and the A-Star automatically supplies 5 V power to an attached Raspberry Pi. In this setup, the Raspberry Pi can handle the high-level robot control while relying on the A-Star for low-level tasks like reading analog sensors and controlling timing-sensitive devices.

Configuration:

Surface mount components only: This version of the A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge (2.7 V to 11 V input voltage) does not include any through-hole components.
Assembled with selected through-hole components : This version of the A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge (2.7 V to 11 V input voltage) is assembled with selected through-hole connectors and components for use as a Raspberry Pi expansion board.

Features:

Dimensions: 65 mm × 56 mm (2.6″ × 2.2″)
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 (some I/O lines are used by on-board hardware)
Convenient 0.1″-spaced power, ground, and signal connection points
Dual bidirectional DRV8838 motor drivers (1.8 A per channel)
Buzzer option for simple sounds and music
3 user-controllable LEDs
3 user pushbuttons
Reset button
Level shifters for interfacing 5 V logic to 3.3 V Raspberry Pi
Power features:
- 5 V power can be sourced from USB or from a 2.7 V to 11 V external supply through on-board regulator (with several access points for connecting external power)
- Switching 5 V regulator enables efficient operation
- 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
- Provides 5 V power to Raspberry Pi
6-pin ISP header for use with an external programmer
Comprehensive user’s guide

Specifications:

Processor: ATmega32U4 @ 16 MHz
RAM size: 2560 bytes
Program memory size: 32 Kbytes
Motor driver: DRV8838
Motor channels: 2
User I/O lines: 26
Input voltage range: 2.7 V to 11 V
Minimum operating voltage: 2.7 V
Maximum operating voltage: 11 V
Maximum output current: 1.5 A
Continuous output current per channel: 1.8 A
Peak output current per channel: 1.8 A
Logic voltage: 5 V
Reverse voltage protection?: Y
External programmer required?: N

Note: This product requires a USB A to Micro-B cable (not included) to connect to a computer

Documents:

Package Includes:

1 x Pololu 3116 / 3117 A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge

Processor Specifications
Speed	16 MHz
Controller Specifications
Family Name	ATmega32U4
Memory Specifications
RAM	2560 bytes
Flash	32 KB flash
Electrical Specifications
Output Current	1.5A
Minimum Operating Voltage	2.7 V
Maximum Operating Voltage	11 V
Physical Attributes
Dimensions	65 mm × 56 mm (2.6″ × 2.2″)
Additional Information
Warranty