Table of contents
- vinciDuino Technical Specs
- Board Layout and placement
- Component and shopping list
The vinciDuino 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.
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 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 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.
Automatic (Software) Reset
Rather than requiring a physical press of the reset button before an upload, the vinciDuino is designed in a way that allows it to be reset by software running on a connected computer. When one of the hardware flow control lines (DTR) of the connector ISP is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.
For the following half-second or so, the bootloader is running on the vinciDuino. While it is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few bytes of data sent to the board after a connection is opened. If a sketch running on the board receives one-time configuration or other data when it first starts, make sure that the software with which it communicates waits a second after opening the connection and before sending this data.
You may also be able to disable the auto-reset by connecting a 10uF Capacitor from Reset line to GND.
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.
Two screw holes allow the board to be attached to a surface or case. Note that the distance between digital pins 7 and 8 is 160 mil (0.16″), not an even multiple of the 100 mil (0.1″) spacing of the other pins. We have added an additional row of headers to simplify the insertion of home made shields.
Board layout and assembly
Rev C. Board layout
Rev C components and placement
Qty Value Device Parts Reference 1 2K2 R-US_R1206 R11 RC1206JR-132K2L 1 Ferrite WE-CBF_1206 L1 2512063007Y3 2 10K R-US_R1206 R2, R9 CR1206-FX-1002ELF 2 22 R-US_R1206 R4, R5 CR1206-FX-22R0GLF 3 1K R-US_R1206 R6, R7, R8 CR1206-FX-1001ELF 1 Red LED1206 PWR LH N974-KN-1 3 1uF CAP1206 C3, C4, C12 VJ1206V105ZXATW1BC 1 ISP AVR_SPI_PRG_6PTH JP3 2x3 2,54 header 3 Green LED1206 L, RX, TX LG N971-KN-1 1 Analog M06SIP J2 1x6 2,54 header 1 POWER M06SIP J4 1x6 2,54 header 1 Serial M06SIP JP2 1x6 2,54 header 1 MBR0520LT MBR0520LT D1 MBR0520LT1G 2 10uF CPOL-EUR/2012-12R C6, C8 T491A106M006AT 1 Digital M08 J1 1x8 2,54 header 1 Reset TAC_SWITCHSMD S2 PTS525S 8 0.1uF CAP1206 C1, C2, C5, C1206C104Z5VACTU C7, C9, C10, C13, C14 1 Digital M10 JP1 1x10 2,54 header 1 USB USBMINIB USB 154-15320-E 2 1206L PTCFUSE-1206 F1, F2 1206L025YR 1 POWER_JACKPTH POWER_JACKPTH JP4 KLDX-0202-A 1 CSM-3X RESONATORSMD Q1 ECS-160-20-3X-TR 2 22pF CAP1206 C15, C16 VJ1206Y103KXAMP 1 ATMEGA32U4-AU ATMEGA32U4-AU U1 ATMEGA32U4-AU 1 vinciDuino BOARD_INFO_ REV_A 1 10nF CAP1206 C11 VJ1206Y103KXAMP 1 L78M05CDT-TR 78M05 IC1 L78M05CDT-TR