The quick specifications.
The top view.
The bottom view.
The pinout diagram.
The Produino Uno 4u is an 8-bit microcontroller board based on the AVR128DA28 chip (see the datasheet). It has 22 digital input/output pins (13 of these can also utilize the ADC onboard for PWM), 10 analog inputs, a USB Type-B connector, a DC Barrel jack for power, an ICSP header and a reset button on board! It contains everything needed to support the microcontroller; all you’ll need to do to get started is simply connect it to a computer with a USB cable or power it with a wall wart adapter and the barrel jack or with a battery and the Vin pins.
The Uno 4u has a onboard CH340 USB-to-serial converter.
Here's the key features of the UNO 4u:
- Hardware compatibility with UNO form factor: The UNO 4u maintains the same form factor, pinout, and a flexible operating voltage of 5V or 3.3V. This ensures a seamless transition for existing shields and projects, leveraging the extensive and unique ecosystem already established for the Arduino UNO.
- Expanded memory and faster clock: Prepare for more precise calculations and the ability to handle complex projects with ease. The UNO 4u boasts increased memory and a faster clock speed, empowering you to tackle demanding tasks effortlessly.
- Extra on-board peripherals: The UNO 4u introduces a range of on-board peripherals, including a 10-bit DAC (Digital-to-Analog), three ACs (Analog Comparators), one ZCD (Zero Cross Detector), three Custom Configurable Logic (CCL), eight Event System channels, one 16-bit internal RTC (Real-Time Counter), three Serial ports and two SPI ports. These additional components provide you with expanded capabilities and flexibility in your designs.
Technical Specifications
| Microcontroller | Microchip AVR128DA28 (AVR®) | |
| USB | USB-B® | Programming Port |
| Pins | Digital I/O Pins | 22 (10 of which are analog) |
| Pins | Analog input pins | 10 |
| DAC | 1 | |
| PWM pins | 13 | |
| Communication | UART | Yes, 3x |
| I2C | Yes, 1x | |
| SPI | Yes, 2x | |
| Power | Circuit operating voltage | 5 V or 3.3V |
| Input voltage (VIN) | 7-12 V (6-20 V limit) | |
| DC Current per I/O Pin | 15 mA (50 mA max) | |
| Clock speed | Main core | 24 MHz |
| Memory | AVR128DA28 | 128 KB Flash, 16 KB RAM |
| Dimensions | Width | 68.6 mm |
| Length | 53.4 mm | |
There are 4 different methods you can use to power your Produino, they include:
- USB (5V) - The Uno 4u will use any 5V power supply with a USB Type B connector. Total current drawn will be limited by the supply, most PCs only provide 250-500mA so bear that in mind if you are looking to power your project directly from a PC.
- 2.1mm Centre-Positive Barrel Jack (Regulates Voltage from 7-12V DC) - The Uno 4u will use any 7-12V source here, as long as it is connected center positive and is 7-12V DC.
- Vin Pin/GND Pin on Power Header on board - This pin can either be a power input (7-12V DC) or to drawn power directly from the barrel jack supply.
- 5V Power Pin on Power Header on Board - This pin can either be used as a 5V output pin or to supply 5V.
When powering the circuit via multiple methods, the 7-12V supply options will take preference over the 5V, and the 5V will be used for data transfer.
The Produino Uno 4u supports running in either 5V or 3.3V modes via a solder jumper. Instructions on setting the board into 3.3V mode are located here.
The AVR128DA28 controller chip contains 128 KB of memory (0.5 KB of this is reserved for the bootloader). It also has 16 KB of Static RAM and 0.5 KB of EEPROM.
Each of the 14 digital pins on the Uno 4u uses 5V logic. Each pin can provide or receive a maximum of 50 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. Control of the nature of each pin takes place within the IDE.
Some of the IO pins have extra functionality:
- Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the CH340 USB-to-TTL Serial chip.
- Additional Serial: The Uno 4u provides two additional hardware serial ports on pins 12 (TX) and 13 (RX), 20 (TX) and 21 (RX).
- External Interrupts: Every pin 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: A0, A1, A2, A3, A4, A5, 2, 3, 4, 5, 6, 7, and 11. Provide 16-bit PWM output with the analogWrite() function.
- Two hardware SPI: SPI0 (7 (SS), 4 (MOSI), 5 (MISO), 6 (SCK)); SPI1 (10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK)). These pins support SPI communication using the SPI library. Note: SPI.swap(0x80) is necessary to swap the SPI0 and SPI1 ports.
- 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 Uno 4u has 10 analog inputs, labeled A0 through A5, also pins 8, 9, 20 and 21 provide analog input. Each of which provides 12 bits of resolution (i.e. 4096 different values).
- TWI: pin 2 or SDA pin and pin 3 or SCL pin. Support TWI communication using the Wire library. There are a couple of other pins on the board:
- 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.
The Produino Uno 4u has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The AVR128DA28 provides UART TTL (5V) serial communication, which is available on digital pins 0 (RX) and 1 (TX). An CH340 on the board channels this serial communication over USB and appears as a virtual com port to software on the computer. The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the Produino board. The RX/TX LED 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).
The AVR128DA28 also supports I2C (TWI) and SPI communication. The Arduino software includes a Wire library to simplify the use of the I2C bus; For SPI communication, use the SPI library.
The Produino Uno 4u can be programmed with the Arduino software (download). Select "Produino Uno 4u from the Tools > Board menu (according to the microcontroller on your board.
Instructions for adding the Produino Uno 4u to the Arduino IDE is located here.
The AVR128DA28 on the Produino Uno 4u comes burned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer.
You can also bypass the bootloader and program the microcontroller through the UPDI (Universal Program and Debug Interface) header using the onboard CH340 USB-to-serial chip or a board that provides UPDI output.
You can force UPDI output by selecting the UPDI mode on the board.
Instructions for selecting the communication modes for the board is located here.
Rather than requiring a physical press of the reset button before an upload, the Produino Uno 4u is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the CH340 is connected to the reset line of the AVR128DA28 via a 100 nano-farad capacitor. When this line 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.
This setup has other implications. When the Uno 4u is connected to either a computer running Mac OS X or Linux, it resets each time a connection is made to it from software (via USB). For the following half-second or so, the bootloader is running on the Uno 4u. 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, makes sure that the software with which it communicates waits for a second after opening the connection and before sending this data.
The Produino Uno 4u has a resettable poly fuse that protects your computer's USB ports from shorts and overcurrent. Although most computers provide their own internal protection, the fuse provides an extra layer of protection. If more than 500 mA is applied to the USB port, the fuse will automatically break the connection until the short or overload is removed.
The maximum length and width of the Uno 4u PCB are 2.7 and 2.1 inches respectively, with the USB connector and power jack extending beyond the former dimension. Four 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 spacing of the other pins.
- Official Produino Uno 4u
Note: USB cable not included.
FAQ
CAN I USE HARDWARE COMPATIBLE WITH THE ARDUINO UNO R3 WITH THE PRODUINO UNO 4u?
Yes, the Produino UNO 4u was specifically designed to ensure compatibility with previous shields and compatible hardware developed for the Arduino UNO R3. The UNO 4u maintains the same mechanical and electrical compatibility, allowing you to seamlessly use your existing shields and hardware with the new board. This makes it easy to upgrade to the UNO 4u without the need for significant changes or adaptations to your projects.
CAN I USE MY SKETCH DEVELOPED FOR THE UNO R3 IN THE UNO 4u?
Yes, if your sketch was developed using the Arduino API.
ARE ALL LIBRARIES COMPATIBLE WITH THE UNO R3 ALSO COMPATIBLE WITH THE UNO 4u?
No, UNO R3 libraries need to be adapted to use the AVR128DA28 ports and timers, however the libraries based on the Arduino API will work.