vinciDuino evo uSD Specifications

The vinciDuino evo uSD has the same shape and connectors as the Arduino Pro, however it uses a different processor, the Atmega32u4. This chip has the same features of the Atmega328 (used in UNO) with the added benefit of having built in USB.

It is based on the original vinciDuino but we have added nice Micro SD card reader. You no longer need to use a breakout board on your data logging, CNC projects, ...
Microcontroller                 ATmega32U4
Operating Voltage               5V
Input Voltage (recommended)     7-12V
Input Voltage (limits)          7-35V
Digital I/O Pins                14 (of which 6 provide PWM output)
Analog Input Pins               6
DC Current per I/O Pin          40 mA
DC Current for 3.3V Pin         50 mA
Flash Memory                    32 KB (-2KB bootloader)
SRAM                            2,5 KB 
EEPROM                          1 KB
Clock Speed                     16 MHz

The vinciDuino evo uSD has the same specifications as the vinciDuino and it works just like its small bro.

Board dimensions

Total board dimensions: 54mm x 54mm


The vinciDuino evo uSD can be powered via the USB connection or with an external power supply. The power source is selected automatically.
External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected by a 2.1mm plugging center-positive plug into the board's power jack. Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector.
The board can operate on an external supply of 6 to 15 volts. If supplied with less than 6V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 6.5 to 12 volts.
The power pins are as follows:
  • VIN. The input voltage to the vinciDuino board when using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.
  • 5V. The regulated power supply used to power the microcontroller and other components on the board. This can come either from VIN via an on-board regulator, or be supplied by USB or another regulated 5V supply.
  • 3V3. Are derived from the on chip regulator and accessible through the 3.3V pin. This pin will only supply up to 50mA. (25 mA when the usb is in use)
  • GND. Ground pins.


The ATmega32U4 has 32 KB. It also has 2,5 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library).

Input and Output


Each of the 14 digital pins on the vinciDuino evo uSD can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:
Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. Broken out on UART header too.
External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.
PWM: 3(8bits), 5(8bits), 6(FastPWM), 9(16bits), 10(16bits), and 11(8/16bits). Provide PWM output with the analogWrite() function.
SPI: Dedicated ISP conector: 14 (SS), 16 (MOSI), 17 (MISO), 15 (SCK). These pins support SPI communication using the SPI library.
LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.
The vinciDuino has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and the analogReference() function. Additionally, some pins have specialized functionality:
TWI: Dedicated pins SDA and SCL. Support TWI communication using the Wire library. Pins are shared with IO 2 and 3.
There are a couple of other pins on the board:
AREF. Reference voltage for the analog inputs. Used with analogReference().
Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.
See also the mapping between Vinciduino pins and ATmega32U4 ports.


The vinciDuino has a number of facilities for communicating with a computer, with another Arduino, or other microcontrollers.
The ATmega32U4The provides UART TTL (5V) serial communication, which is available on digital pins 0 (RX) and 1 (TX), or through the dedicated header connector.
The built-in USB controller channels this serial communication over USB and appears as a virtual com port to software on the computer. The 32U2 firmware uses the standard USB COM drivers, and no external driver is needed.
However, on Windows, a .inf file is required. The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the Arduino board. The RX and TX LEDs on the board will flash when data is being transmitted via the USB-to-serial chip and USB connection to the computer (but not for serial communication on pins 0 and 1).
A SoftwareSerial library allows for serial communication on any of the vinciDuino's digital pins.
The ATmega32U4 also supports I2C (TWI) and SPI communication. The Arduino software includes a Wire library to simplify use of the I2C bus; see the documentation for details. For SPI communication, use the SPI library.


The Vinciduino can be programmed with the Arduino software (download). Select "Arduino Leonardo from the Tools > Board menu. For details, see the reference and tutorials.
You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header.
Overcurrent Protection
The vinciDuino Uno has 2 resettable polyfuses that protects your computer's USB ports from shorts and over-current. Although most computers today provide their own internal protection, the fuse gives you that extra layer. If more than 500 mA is required, the fuse will automatically break the connection until the short or overload is removed.

uSD Card reader

Built in Micro SD (uSD) card reader. Enable pin is shared with IO 13 and can be used with the original Arduino uSD libraries: Arduino library or the excellent library form Sparkfun and Adafruit.

Schematics and CAD files

Schematic files: download.
Eagle CAD files: download.