A-Star 32U4 Mini LV – Pololu 3103
The A-Star 32U4 Mini LV is a programmable module based on the ATmega32U4 from Atmel. Unlike competing products, it has an onboard switching step-up/step-down regulator that allows it to be powered efficiently from a 2.7 V to 11.8 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 Atmel’s ATmega32U4 AVR microcontroller, 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.
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.
- Dimensions: 1.9″ × 0.7″ (1.95″ × 0.7″ including USB Micro-B connector)
- Programmable 16 MHz Atmel ATmega32U4 AVR microcontroller
- 32 KB flash (4 KB used by bootloader, leaving 28 KB available for user program by default)
- 2.5 KB SRAM
- 1 KB EEPROM
- Native full-speed USB (12 Mbps)
- Preloaded with Arduino-compatible bootloader (no external programmer required)
- All I/O lines from the ATmega32U4 broken out in a compact package
- 26 general-purpose I/O pins available along the sides of the board
- 7 pins can be configured as hardware PWM outputs
- 12 pins can be configured as analog inputs
- 3 user-controllable LEDs
- Reset button
- Can be powered from USB or from an external source:
- ULV: 0.5 V to 5.5 V
- LV: 2.7 V to 11.8 V
- SV: 5 V to 36 V
- Switching regulator enables efficient low-power operation
- Power selection circuit with seamless switching between power sources and overcurrent protection
- Reverse-voltage protection on external power inputs
- Precision 16 MHz crystal
- 6-pin ISP header for use with an external programmer
|Processor:||ATmega32U4 @ 16 MHz|
|RAM size:||2560 bytes|
|Program memory size:||32 Kbytes1|
|User I/O lines:||26|
|Input voltage range:||2.7 V to 11.8 V (LV)|
|Minimum operating voltage:||2.7 V|
|Maximum operating voltage:||11.8 V|
|Maximum output current:||1.5 A2|
|Logic voltage:||5 V|
|Reverse voltage protection?:||Y3|
|External programmer required?:||N|
- Note that 4 KB of the MCU’s 32 KB of flash memory is used by the pre-installed USB bootloader. All 32 KB is available when programming via the ISP header rather than the bootloader.
- Available current depends on input voltage, current consumed by the board, ambient conditions, and regulator topology. See product documentation and performance graphs for details.
- On Bat+ (LV, SV) or Bat- (ULV).
- Size: 49.7 x 17.8 x 5.85 mm (1.95″ x 0.7″ x 2.23″)
- Weight: 3.4 g
A pair of 1×17-pin breakaway 0.1″ male headers is included with the A-Star 32U4 Micro, which can be soldered in to use the board with perfboards, breadboards, or 0.1″ female connectors. Also included is a 2×3 header that can be installed to allow external programming of the microcontroller through the AVR ISP interface, such as with Pololu’s USB AVR programmer. The board has two mounting holes that work with #2 and M2 screws (not included).