SKU: 27685105773

A-Star 32U4 Micro Pololu 3101

$16.64 $18.49
Save 10%
No.2 Bestseller on ezbeecleaning.com >

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 11 - Jul 16

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

A-Star 32U4 Micro Pololu 3101The A Star 32U4 Micro is a tiny programmable module featuring the ATmega32U4 AVR microcontroller. It packs a Micro USB interface and 18 digital input output pins (of which 7 can be used as PWM outputs and 8 as analog inputs) onto a board measuring only 1 0. 6 and ships preloaded with an Arduino compatible bootloader. A Star 32U4 Micro, bottom view with U. S. quarter for size reference. Overview The Pololu A Star 32U4 Micro is a general purpose

The A-Star 32U4 Micro is a tiny programmable module featuring the ATmega32U4 AVR microcontroller. It packs a Micro-USB interface and 18 digital input/output pins (of which 7 can be used as PWM outputs and 8 as analog inputs) onto a board measuring only 1″ × 0.6″ and ships preloaded with an Arduino-compatible bootloader.


 

A-Star 32U4 Micro, bottom view with U.S. quarter for size reference.

Overview

The Pololu A-Star 32U4 Micro is a general-purpose programmable module 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. Onboard features of the A-Star (abbreviated A*) include a 16 MHz resonator, a USB Micro-B connector, an in-system programming (ISP) header, and a pair of indicator LEDs. A voltage regulator and power selection circuit allow the board to be powered from either USB or an external 5.5 V to 15 V source, while a resettable PTC fuse on the USB VBUS supply and reverse protection on VIN help protect it from accidental damage.

The A-Star 32U4 Micro breaks out 15 general-purpose I/O lines along two rows of pins, including 7 usable as PWM outputs and 8 usable as analog inputs; another three GPIO pins can be accessed through the 6-pin ISP header. It fits all this into a 20-pin dual in-line package (DIP) measuring only 1″ × 0.6″ (even smaller than competing ATmega32U4 boards like the Teensy 2.0 and Pro Micro), and 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.

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

Features

  • Dimensions: 1″ × 0.6″ (1.05″ × 0.6″ including USB Micro-B connector)
  • Programmable 16 MHz 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)
  • Many I/O lines in a small package
    • 15 general-purpose I/O pins available along the sides of the board
    • 3 additional I/O pins available on ISP header
    • 7 pins can be configured as hardware PWM outputs
    • 8 pins can be configured as analog inputs
  • 2 user-controllable LEDs
  • Can be powered from USB or external 5.5 V to 15 V source on VIN
  • PTC fuse on VBUS supply
  • Reverse-voltage protection on VIN supply
  • 6-pin ISP header for use with an external programmer
  • Comprehensive user’s guide

Arduino compatibility

The A-Star 32U4 ships with a preloaded Arduino-compatible bootloader (which uses 4 KB of flash memory, leaving 28 KB available for the user program). We provide a software add-on that enables the board to be easily programmed from the Arduino environment.

The A-Star 32U4 uses the same microcontroller as the Arduino Leonardo and Arduino Micro and runs at the same frequency, making it just as powerful. Although the larger boards offer a few more I/O pins, the A-Star 32U4 Micro fits in an area half that of the Arduino Micro, and it takes up only 11% as much area as a standard full-size Arduino!

 

Pololu A-Star 32U4 Micro, Pololu A-Star 32U4 Mini SV, Arduino Micro, and Arduino Leonardo.

Pinout

 

This diagram identifies the I/O and power pins on the A-Star 32U4 Micro; it is also available as a printable PDF (409k pdf). For more information about the ATmega32U4 microcontroller on this board, see Microchip’s ATmega32U4 documentation.

Printed on the A* circuit board are indicators that you can use to quickly identify each pin’s capabilities: a triangle next to the pin means it can be used as an analog input, and a square wave symbol under the pin number means it can be used as a PWM output.

The board can either be powered directly from the USB 5 V supply or from a separate 5.5 V to 15 V source on the VIN pin, which is reduced to 5 V by a 100 mA low-dropout (LDO) regulator; you can access this 5 V supply through the 5V power output pin. Additionally, the ATmega32U4 contains an internal 3.3 V regulator whose output is available on the 3V3 pin. Current drawn from the 3V3 output should not exceed about 50 mA, and when the board is being powered through VIN, the sum of the 5V output current, 3V3 output current, GPIO output current, and current used by the board itself (typically about 25 mA) should not exceed 100 mA.

Included hardware

A 1×20-pin breakaway 0.1″ male header 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. (The headers might ship already separated into two 1×10 pieces.) 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 our USB AVR programmer.

A-Star 32U4 Micro with included optional headers.

A-Star 32U4 Micro with soldered headers and connected USB cable.

The A-Star family

 

From top to bottom: A-Star 328PB Micro, 32U4 Micro, 32U4 Mini SV, and 32U4 Prime SV.

The A-Star 32U4 Micro is a part of our larger A-Star family, all of whose members are based on AVR microcontrollers and are preloaded with Arduino-compatible bootloaders. The table below shows some key features and specifications of our A-Star microcontroller boards to help you choose the right one for your application.



A-Star 328PB Micro A-Star 32U4 Micro A-Star 32U4 Mini ULV

A-Star 32U4 Mini LV

A-Star 32U4 Mini SV		 A-Star 32U4 Prime LV

A-Star 32U4 Prime SV		 A-Star 32U4 Robot Controller LV

A-Star 32U4 Robot Controller SV
Microcontroller: ATmega328PB ATmega32U4
User I/O lines: 24 18 26 26(1) 26(1)
PWM outputs: 9 7 7 7 7(1)
Analog inputs: 8 8 12 12 12(1)
Ground access points: 6 2 4 43 44
User LEDs: 1 2 3 3 3
User pushbuttons: — — — 3 3
USB interface: Yes Yes Yes Yes
Reset button: Yes   Yes Yes Yes
Power switch:     Yes Yes
Buzzer option:     Yes Yes
microSD option:     Yes  
LCD option:     Yes  
Motor drivers:       Yes
Operating voltage: 3.3V VCC: 3.8 V to 15 V
5V VCC: 5.5 V to 15 V		 5.5 V to 15 V ULV: 0.5 V to 5.5 V
LV: 2.7 V to 11.8 V
SV: 5 V to 40 V		 LV: 2 V to 16 V
SV: 5 V to 36 V		 LV: 2.7 V to 11 V
SV: 5.5 V to 36 V
Regulator type: 3.3 V or 5 V linear 5 V linear 5 V switching

ULV: step-up
LV: step-up/step-down
SV: step-down		 5 V switching

LV: step-up/step-down
SV: step-down		 5 V switching

LV: step-up/step-down
SV: step-down
Regulated current:(2) 100 mA 100 mA ULV: 500 mA
LV: 1 A
SV: 800 mA		 LV: 1.8 A
SV: 1 A		 LV: 1 A
SV: 1.5 A
Dimensions: 1.3″ × 0.7″ 1″ × 0.6″ 1.9″ × 0.7″ 2.8″ × 2.1″ 2.6″ × 2.2″
Weight: 1.5 g(3) 1.3 g(3) 3.4 g(3) 13 g to 33 g 14 g to 23 g
1 Some microcontroller resources are used by on-board hardware.
2 These values are rough approximations for comparison purposes. Available current depends on input voltage, current consumed by the board, ambient conditions, and regulator topology. See product documentation and performance graphs for details.
3 Without included optional headers.

Specifications

Parameter Value
Size 0.6″ × 1.05″ × 0.18″
Weight 1.3 g
Processor ATmega32U4 @ 16 MHz
Ram size 2560 bytes
Program memory size 32 Kbytes
Motor channels 0
User i/o lines 18
Minimum operating voltage 5.5 V
Maximum operating voltage 15 V
Logic voltage 5 V
Reverse voltage protection? Y
External programmer required? N
PCB dev codes ac01a
Other PCB markings 0J8063

Resources

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 27685105773

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.9 ★★★★★
Based on 1124 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
T
Verified Purchase
Tallie
Boise, US
★★★★★ 5
hobbyist only
Purchased to replace a 15 year old Epson. I still have three weeks to decide to return this so I will edit this review if I decide to do that. PROS: After a few test prints, I love the quality of color, the accuracy of reproduction to what I see on my monitor, and the number of choices for print size and quality. I found, as others complained, that with cheap gloss paper there was puddling of ink. When I switched to my best papers, especially my favorite highest quality matte finish, the results were astounding and I'd do matte for everything. As for ink usage, I made the choice to go with a cartridge printer instead of the newer high-volume inks because I wanted the archival quality. Test the output for your needs, because I found the "draft" setting produced better on gloss paper. CONS: Like so many electronics now, you only get instructions if you download and print them. Second, when the printed photo feeds out, it has been curled and as it feeds into the receiving drawer, wants to drag the wet ink against the body of the machine. You have to be there to watch and push it down with a finger. Cheaper gloss paper in 4x6 size curled up in a little wet roll 1/2" diameter and is not usable AT ALL. The miniature screen on which to select papers is ridiculous. I wish the computer interface let you make the choices on your computer, but it does not.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 6, 2020
H
Verified Purchase
Howard Bollinger
Cuba, US
★★★★★ 1
Defective printer and poor wifi performance
I cannot recommend that anyone buy this printer. At this price, I expected a consistently working and decent quality printer. For initial wireless setup with a Mac, we had to spend 45 minutes on the phone with Epson technical support. That got it working. It worked for a couple of weeks and then the printer would frequently lose its wifi connection even though our internet is high quality cable and very consistent. We'd have to turn this printer off and on repeatedly to re-establish the wifi connection. Then after 6 weeks it stopped working totally. After another 45 minute call with Epson, they said it had a hardware failure and we had to return it to Epson and would receive a refurbished unit. This is less than 2 months after buying a new high priced printer that they are suggesting we accept a refurbished unit. Finally Epson said they'd send a new one. We got the new one and did our customary call to tech support to set it up for wireless with a Mac. It turns out they forgot to send the factory ink cartridges in this replacement printer that are required to do an initial setup. We have the Epson cartridges that are spec'ed for this printer, but they have to be the ones that COME INSIDE the printer for the printer to begin its initial setup. So after another 45 minute call, Epson now says they have to send us new ink cartridges for the printer to even print a single piece of paper - even though we have Epson ink cartridges purchased just for this computer. So after weeks of no printer for our business, we now have to wait for another shipment from Epson. Then we will have the next 45 minute call to set it up.. This painful and costly experience has had way too many headaches - all caused by Epson defects and mistakes. We will not be buying Epson again.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 7, 2018
W
Verified Purchase
WhatTheSnow
Chelsea, US
★★★★★ 5
A must have high quality Photo Printer for cheap!
If you’re searching for a high quality printer without breaking the bank , this is the printer for you. I had spent a good amount of time researching various printers and the picture quality they offered . I really spent my time looking this up . I found that the Picture quality on this printer is incredible . If you look at other models that can print 13x19 they cost way more. Now the ink capacity I’m not entirely sure about but I do know the ink can be expensive but it’s a trade off for getting an affordable printer without breaking super high quality pictures . Setup was very straight forward and it makes it essentially easy for anyone to connect to their network to print wired or wireless. You have the ability to print from your phone which is really amazing as well . All around this printer is great and if you’re hesitant you should just pull the trigger because you get quality with this model and affordability .
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 6, 2025
C
Verified Purchase
christina graves
Charlottesville, US
★★★★★ 4
Ink is a problem
Printer is great. It prints very nicely.. had no problem setting up.. it all works fine. What I didn't like is the ink is kind of expensive and doesn't seem to last long. Once one color is out .. you can't use at all. Says "print in black" but it only allows that a few pages then it's done even tho there is black ink left. Epson customer service kind of sucks also.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 10, 2025
A
Verified Purchase
A. R. Masters
Los Angeles, US
★★★★★ 5
Correction: Excellent value, quality and ease of use for color & grey scale; Wi-Fi firmware updates
Straightforward to install on my home WiFi network. The controls and screen are easy to navigate. Firmware updates can be done via WiFi—so much better than downloading an installer to a computer. Surprised that the maximum borderless print size is A3+. I don’t care, because I don’t mind a thin border on 13x19” paper, and intend to print 12x18” or smaller anyway for framing. Good results on real-world test prints with default color and tonal settings in Apple Photos. Astonishingly, perfect color and tonal range in my full-spectrum, full-dynamic range test print of a storefront on 13x19” Matte paper. A garden scene had true hues—borderless on 4x6” glossy paper—but was a bit dark. You wouldn’t notice if you only saw the print. Full tonal range B&W image on glossy paper lost some highlight detail and mid-tone pop compared to what I got from a commercial print shop using Luster paper, but I’m not seeing a color cast reported by others, which is very good news. I bought Epson again after a long hiatus because 1) I have a big stock of paper from pre-covid days, 2) ink cost is not a problem for my limited photo printing needs, and 3) the recent price drop offered a very low up-front cost. This one is smaller and very much quieter than its predecessor. It offers Air Print connectivity, but I prefer WiFi, even from mobile devices. Pretty happy so far. Already useful and B&W may improve with experimentation.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 31, 2024

recommand products

Lifebuoy Soap Germ Guard+ : 4x125 gms
148.00
Moov Cream Pain Relief Specialist : 50 gms
101.50
Margo Neem Soap : 4x100 gms
158.00
Lakme 9to5 Primer + Matte Lipstick - Pink Party : 3.6 gms
261.50
Vintage Carlo Nason Hand Blown Glass Chandelier
2900.00