A-Star 32U4 Prime SV microSD

The A-Star 32U4 Prime SV is a programmable board based on Atmel’s ATmega32U4 microcontroller and arranged in the common Arduino form factor.

AUD$ 40.95

Out of Local Stock  

We can ship 39 more in 7 days

Our Code: SKU-003523

Supplier Link: [Pololu MPN:3114]


Description

Overview

A-Star 32U4 Prime SV, bottom view

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 analogue 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: SV, which features a green solder mask and a switching step-down regulator that allows operation from 5 V to 36 V, and 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. 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 SV microSD with LCD

A-Star 32U4 Prime SV (5 V to 36 V) configurations:

A-Star 32U4 Prime LV microSD with LCD

A-Star 32U4 Prime LV (2.7 V to 11.8 V) configurations:

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.

A-Star 32U4 Prime pinout diagram

A-Star 32U4 Prime power distribution diagram

Features

  • 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 analogue 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
  • Comprehensive user’s guide

Details for item #3114

A-Star 32U4 Prime SV microSD (1)

This configuration of the A-Star 32U4 Prime SV includes microSD support and is assembled with through-hole components as shown in the picture above so that all the basic features can be used without any additional soldering. The standard female headers common to many Arduinos are preinstalled, as is the 2×3 male ISP header, buzzer, DC power jack, and shorting block headers for enabling the microSD hardware, buzzer, and battery voltage monitor. This is the SV version of the A-Star Prime, which operates from 5 V to 36 V.

A-Star 32U4 Prime SV 5 V regulator

A major feature of the A* Prime SV is its power system, which allows it to efficiently operate from a 5 V to 36 V external source. The input voltage is regulated to 5 V by an ISL85410 switching step-down (buck) converter from Intersil, a higher-power version of the ISL85415 used on the smaller A-Star 32U4 Mini SV. (We also make a standalone regulator based on this integrated circuit.)

As shown in the left graph below, the SV’s 5 V switching regulator has an efficiency – defined as (Power out)/(Power in) – of 80% to 95% for most combinations of input voltage and load.

Typical efficiency of the 5 V regulator on the A-Star 32U4 Prime SV

Typical maximum output currents of the 5 V regulators on the A-Star 32U4 Prime LV and SV

The A-Star’s components, including the microcontroller and LEDs, draw 30 mA to 40 mA in typical applications (without the buzzer, microSD card, or an LCD). The rest of the regulator’s achievable output current, which depends on input voltage as well as ambient conditions, can be used to power other devices. The green line in the right graph above shows the output currents where the regulator’s output voltage drops below 4.75 V. These currents are close to the limits of the regulator’s capability and generally cannot be sustained for long periods; under typical operating conditions, a safe limit for the maximum continuous regulator output current is approximately 1 A.

The dropout voltage of a step-down regulator is defined as the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to assure the target output can be achieved. As can be seen in the graph below, the dropout voltage of the Prime SV’s regulator increases approximately linearly with the output current. For light loads where the dropout voltage is small, the board can operate down to 5 V. However, for larger loads, the dropout voltage should be taken into consideration when selecting a power supply; operating above 6 V will ensure the full output current is available.

Typical dropout voltage of the 5 V regulator on the A-Star 32U4 Prime SV

Note: Batteries can have much higher voltages than their nominal voltages when fully charged, so be careful with nominal voltages above 24 V. A 36 V battery is not appropriate for this product.

Arduino compatibility

The A-Star 32U4 Prime 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 and an Arduino library to make it easy to use the additional on-board hardware. The A-Star 32U4 has the same microcontroller and form factor as the Arduino Leonardo, and it runs at the same frequency, so we generally expect it to work with shields that are compatible with the Leonardo and similar boards. Note that the Prime has additional components and connection points, so you should make sure these do not physically interfere with any shield you are considering using. The following table shows how the Prime compares to the Leonardo and Uno:


Arduino Uno R3

Arduino Leonardo

A-Star 32U4 Prime LV

A-Star 32U4 Prime SV
Microcontroller: ATmega328P ATmega32U4 ATmega32U4
Clock: 16 MHz resonator 16 MHz crystal 16 MHz crystal
User I/O lines: 20 23 26
PWM outputs: 6 7 7
Analogue inputs: 6 12 12
Ground access points: 4 4 43
User LEDs: 3 3 3
User pushbuttons: 3
Reset button:
Power switch:    
Buzzer option:    
microSD option:    
LCD option:    
Arduino-compatible
bootloader:
USB connector: B Micro-B Micro-B
USB/regulator
power selection:
partial partial TPS2113A
High-performance
reverse-voltage
protection:
   
Recommended
input voltage:
7 V to 12 V 7 V to 12 V 2.7 V to 11.8 V 5 V to 36 V
Regulator type (5 V): linear linear switching
step-up/step-down
switching
step-down
Available
5 V
output
current:
at 3 V in 0.75 A
at 5 V in 1.5 A 0.2 A
at 7 V in 1.0 A 1.0 A 1.5 A 1.0 A
at 9 V in 0.5 A 0.5 A 1.5 A 1.0 A
at 11 V in 0.35 A 0.35 A 1.5 A 1.0 A
at 24 V in 1.0 A
via USB
connector
0.5 A(1) 0.5 A(1) 1.5 A(1) 1.5 A(1)
Weight: 28 g 20 g 13 g to 33 g

1 With sufficiently capable USB power supply.

Side-by-side comparison of the A-Star 32U4 Prime LV microSD to the Arduino Leonardo

The A-Star family

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

The A-Star 32U4 Prime is a part of our larger A-Star 32U4 family, all of whose members are based on the same ATmega32U4 microcontroller, feature native USB interfaces, 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 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: ATmega32U4 ATmega32U4 ATmega32U4 ATmega32U4
User I/O lines: 18 26 26(1) 26(1)
PWM outputs: 7 7 7 7(1)
Analogue inputs: 8 12 12 12(1)
Ground access points: 2 4 43 44
User LEDs: 2 3 3 3
User pushbuttons: 3 3
Reset button:  
Power switch:    
Buzzer option:    
microSD option:      
LCD option:      
Motor drivers:      
Operating voltage: 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 36 V
LV: 2.7 V to 11.8 V
SV: 5 V to 36 V
LV: 2.7 V to 11 V
SV: 5.5 V to 36 V
Regulator type: linear switching

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

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

LV: step-up/step-down
SV: step-down
Regulated current:(2) 100 mA ULV: 500 mA
LV: 1 A
SV: 500 mA
1 A LV: 1 A
SV: 1.5 A
Dimensions: 1″ × 0.6″ 1.9″ × 0.7″ 2.8″ × 2.1″ 2.6″ × 2.2″
Weight: 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

Dimensions

Size: 2.8″ × 2.1″ (common Arduino form factor)
Weight: 20 g

General specifications

Processor: ATmega32U4 @ 16 MHz
RAM size: 2560 bytes
Program memory size: 32 Kbytes1
Motor channels: 0
User I/O lines: 26
Input voltage range: 5 V to 36 V (SV)
Minimum operating voltage: 5 V2
Maximum operating voltage: 36 V
Maximum output current: 1.0 A3
Logic voltage: 5 V
Reverse voltage protection?: Y
External programmer required?: N

Notes:

1
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.
2
For light loads. The regulator's dropout voltage increases approximately linearly with the load, from a few millivolts at no load up to around 0.9 V at 1 A.
3
Available current depends on input voltage, current consumed by the board, ambient conditions, and regulator topology. See product documentation and performance graphs for details.

Resources

Documentation and other information

Pololu A-Star 32U4 User’s Guide (Printable PDF)

User’s manual for the Pololu A-Star 32U4 family of user-programmable boards.


File downloads

A-Star 32U4 Prime pinout and power distribution diagrams (1MB pdf)
Printable pinout and power distribution diagrams of the A-Star 32U4 Prime (applies to both LV and SV versions).
Pololu A-Star/Zumo 32U4 Software and Drivers (version 2.0.0) (98k zip)
This download contains the Windows drivers for the A-Star, the add-on for the Arduino IDE, the source code and compiled version of the bootloader, and a configuration file that some Linux users will need.
A-Star 32U4 Prime SV schematic diagram (1MB pdf)
Printable schematic diagram of the A-Star 32U4 Prime SV.
Dimension diagram of the A-Star 32U4 Prime SV (4MB pdf)
A-Star 32U4 Prime SV drill guide (205k dxf)
This DXF drawing shows the locations of all of the board’s holes.

Recommended links

A-Star 32U4 Arduino library
The AStar32U4 library for the Arduino IDE helps interface with the on-board hardware on the A-Star 32U4 controllers.
AStar32U4 library documentation
Documentation for the AStar32U4 Arduino library.
A-Star/Zumo 32U4 repository on GitHub
This repository contains the A-Star Arduino add-on files, the Windows drivers, and the source code of the bootloader, as well as the AStar32U4Prime library and the Zumo32U4 library.
Arduino Software
Arduino integrated development environment (IDE) software
ATmega32U4 documentation
Atmel’s product page for the ATmega32U4, with links to its datasheet and other resources.
AVR Libc Home Page
The web site for AVR Libc, which is the standard library of functions that you can use with C and C++ on the AVR.
Pololu A-Star and Orangutan Forum Section
The A-Star and Orangutan discussion section of the Pololu Robotics Forum.
AVR Freaks
AVR community with forums, projects, and AVR news.
AVRDUDE
AVRDUDE is a cross-platform command-line utility for programming the flash memory on AVR microcontrollers.
LUFA – the Lightweight USB Framework for AVRs
LUFA is an embedded software library written in C that can be used to create USB applications on USB-capable AVRs. It comes with a large library of example USB applications and bootloaders.
Atmel Studio
Atmel’s free integrated development environment (IDE) for AVRs.
WinAVR
A free, open-source suite of development tools for the AVR family of microcontrollers, including the GNU GCC compiler for C/C++.
LPS Arduino library
This is a library for the Arduino that interfaces with our LPS25H and LPS331AP pressure/altitude sensor carriers as well as the pressure sensor on the AltIMU-10 v3 (it also works with the original AltIMU-10). It makes it simple to read the raw pressure data from the sensor, and it provides functions to help calculate altitude based on the measured pressure.
Arduino library for addressable RGB LED strips from Pololu

This library allows you to control an arbitrary number of WS281x-Based Addressable RGB LEDs from an Arduino.

LSM303 Arduino library
This is a library for the Arduino that interfaces with our LSM303D, LSM303DLHC, and LSM303DLM 3D compass and accelerometer carriers as well as the compass and accelerometer ICs on the MinIMU-9 v3 and AltIMU-10 v3 (it also works with older versions of those boards, some of which used the LSM303DLH and LSM303DLHC). It makes it simple to configure the device and read the raw accelerometer and magnetometer data, and it has a function for computing the tilt-compensated heading for those looking to use the LSM303 as a tilt-compensated compass.
L3G Arduino library
This is a library for the Arduino that interfaces with our L3GD20H and L3GD20 3-axis gyro carriers as well as the gyros on the MinIMU-9 v3 and AltIMU-10 v3 (it also works with older versions of those boards, some of which used the L3G4200D and the L3GD20). It makes it simple to configure the device and read the raw gyro data.
Arduino Library for the Pololu QTR Reflectance Sensors
This guide explains how to use the QTRSensors library to read Pololu QTR reflectance sensors and QTR sensor arrays with Arduinos and Arduino-compatible devices like the Pololu Orangutan robot controllers.

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