Prestissimo Uno+ Documentation
The Prestissimo Uno+ development board is design for fast ands easy electronics prototyping and development. It is 100% compatible with the existing arduino IDE and ecosystem but can also be used with more complex IDES such as Atmel Studio. The Uno+ is based on the new ATMEGA328PB which offers more GPIO, analog inputs, PWM and serial comunication blocks than the original Arduino Uno. Makers, Engineers and Developer are provided the ease of use and reliability of the original Arduino Uno/ATMEGA328P but with imrpoved functionality.
The Uno+ can be either be powered of the USB port (when connected to a computer) , through a DC power barrel connector or via the VIN pin which connects to a voltage regulator. When connected to USB, the board is powered of the 5V supplied by the USB bus. The Vin pin and DC power connector accept a maximum of 15V* and a minimum of 7V*. Do not attempt to power the board of the Vin pin/DC power connector and the USB connectir at the same time as this could result in a short. The DC barrel connector accepts 2.1mm plugs (same as Arduino Uno).
5V can be drawn from the 5V pin. It can source up to 1A when powered of an external powereupply (500ma when powered of USB). These values include unclude current drawn by the Prestissimo Uno+ itself.
The 3.3V pin provides a regulated 3.3V output. A maximum of 150ma is available from this pin.
Each Digital output can source/sink 20ma of current. The Absolute maximum is 40 ma.
* the absolute maximum and minimum input is 6-20V, functionality cannot be guaranteed above 15V or below 7V given a 1.5V droput voltage at 1A.
The Prestissimo Uno+ uses a modified version of the optiboot bootloader. It occupies 512 bytes program memory.
USB to Serial
Unlike the Arduino Uno, which uses an additional atmega mcu to act as the USB-UART bridge, the Prestissimo Uno+ employs a more reliable dedicated hardware USB to serial converter. It is capable of baud rates from 300 baud to 3Mbaud. During programming, the USB to serial converter performs a software reset and uploads the code via the UART interface on pins 0 and 1. A manual reset can be performed by pressing the reset button at the top left hand corner of the board.
The ATmega328PB has 32 KB (with 0.5 KB occupied by the bootloader). It also has 2 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library
The Prestissimo Uno+ offers two UART/USART ports. Serial is located on pins 0 (RX0) and 1 (TX0) it can also be called using Serial1. The 2nd port is on pins 11 (RX1) and 10 (TX1), it is called using Serial2. Additional serial ports can be implemented using the SoftwareSerial library via "bit banging" at a significant processing overhead and whith reduce performance which is often used with the Arduino Uno which does not have a second hardware UART.
The Prestissimo Uno+ offers two I2C controllers. It can function as either a master or slave. The first controller is on the SCL0/SDA0 pins. These connection are also accessible on pins A4 (SDA) and A5 (SCL). The second I2C controller is on pins 23 (SCL1) and 22 (SDA1). They are acessed by Wire and Wire1 libraries respectively
The Prestissimo Uno+ offers two SPI controllers. It can function as either a master or slave. SPI0 (via the SPI library) is accessible from the ICSP header and and pins 13 (SCK), 12 (MISO), 11 (MOSI), and 10 (SS). SP1 (via the SPI1 library) is accesible on pins 15/A1 (SCK), 14/A0 (MISO), 21/A7 (MOSI), and D20/A4 (SS)
Users may bypass the bootloader by programing via the ICSP header using an in circuit programmer (shuch as ArduinoISP, atmel-ICE etc.) This will overridden the bootloader meaning the board will no longer be able to be programed over the serial interface. This will free up the 512 bytes used by the bootloader.