Atmega32u4 supports usb port internally, so it is possible to connect the board directly to the computer and by the pre-loaded you may use Arduino IDE easily. Pololu company - made these A-Star boards based on Atmege32u4 microcontroller.
Atmega32u4 supports internal 32 kB flash memory, 2.5 kB SRAM and inter lan usb interface. There is a micro usb connector on the board for computer connection but the kit does not include usb cable. Moreover, there are ISP pins, LEDs and a crystal oscillator on the board. The board is supplied bu usb connector or an external 2.7 - 11.8 V voltage source thanks to the step - down regulator.
All A-Star Mini series boards have a 5V high efficiency switched regulator on-board. Different versions support diffrent input voltages
- A-Star 32u4 Mini ULV: 0.5 - 5.5 V input voltage
- A-Star 32u4 Mini LV: 2.7 - 11.8 V input voltage
- A-Star 32u4 Mini SV: 5 - 36 V input voltage
The boards provide reverse voltage and overcurrent protection.
There are 26 I/O pins on A-Star 32u4 Micro (7 of them are PWM out, 12 of them are Analog in). The board is compatible with breadboard.
User Guide contains detailed information about A-Star Mini ULV and the other A-Star boards.
Note: The kit does not include Micro Usb cable.
Features:
- Sizes: 4.8 x 1.8 cm
- Programmable 16 Mhz Atmega3284 microcontroller
- 32 kB Flash memory (4 kB is used by bootloader)
- 2.5 kB SRAM
- 1 kB EEPROM
- Internal usb port
- Pre-loaded Arduino bootloader
- 26 digital I/O pins
- 7 pin as PWM
- 12 pin as Analog in
- User controlled 3 LEDs
- Reset button
- Usb or external supply
- Power protection for usb line
- Reverse voltage protection for external supply
- 6-pin ISP connentors (for external programming),
- Extensive User Guide
Details of A-Star32u4 Mini:
Mini ULV version is able to work with 2.7 - 11.8 V input voltage. There is TPS63061 5V step - up / step - down regulator on-board.
You may see efficiency graphics og A-Star boards below.
The output of the regulator on Mini ULV board is directly connected to input voltage. As seen in the graph, when the input voltage is 1 V, output current becomes around 100 mA. When the input voltage is 3.6 V, output current is getting closer to 750 mA. These currents are maximum values, so, the board can not work under these values stabile. 60 - 70 percent of these values are ideal to use. There are high temperature protection for regulators.
A-Star 32u4 holds the same microcontroller as Arudino Leonardo and Arduino Micro but provides smaller size and more functions.
Pin Mapping:
