28Pins AVR Microcontroller Board Pro

28Pins is an open-source electronics platform based on easy-to-understand hardware and software. This board is inexpensive and completely open-source thus empowering users to build incredible devices satisfying their particular needs.
Volume price table
Quantity 1 - 9 10 - 99 100 - 999 1000+
Unit price* 37 EUR 35 EUR 27 EUR 22 EUR

* For orders exceeding 1 000 units, or customized configuration quotes, please submit your request.

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28Pins AVR Microcontroller Board Pro is compatible with Arduino UNO Rev. 3, including several useful improvements:

• Both RESET pins (328P and 16U2) are driven through an open drain buffer. This adds an option to debug the microcontrollers through dWire interface.

• ATMEGA16U2 can be used as a universal AVRISP MKII programmer. Once the firmware is changed, it can load and debug firmware of the on-board ATMEGA328P or any other MCU.

Possible switching between 5V or 3.3V pin voltage by simple change of the JP4 jumper link.

• dWire debugger (if correct firmware is used, 16U2 can work as dWire debugger)

• Micro USB (any mobile phone or tablet charger is suitable to power the board)

• User Button added

• DFU Disable jumper

• ATMEGA328P can be programmed from ATMEGA16U2

• SPI programming support

• dWire debugging support

• on board +3.3V / 1.5A regulator

• power input: micro USB or soldered wires

• power voltage: +3V3 / +5V IO voltage configuration

• e-Fuses preprogrammed

• dimensions: 68.6 x 53.4 mm

• -20°C to +85°C Extended temperature range

• Lead free / RoHS compliant

• FLASH: 32kB


• RAM: 2kB

• clock: 16MHz (for +5V) / 10MHz (for +3.3V)

• up to 20 input / output pins from which:
     • 20x digital input/output
     • 6x PWM output
     • 6x analog input (10-bit AD)
     • Serial port
     • SPI
     • I2C
     • user LED
     • user button
     • reset button

• FLASH: 16kB

• EEPROM: 512B

• RAM: 512B

• clock: 16MHz (for +5V) / 8MHz (for +3.3V)

• 4x digital input / output

• 2x user LED



• Serial port (shared with 328P)

• DFU programming support

• AVRISP MKII firmware available

This product was discontinued on December 31, 2021.

Contact the sales department if interested to order discontinued product.

For the documentation, flashing procedures, firmware compilation, and latest updates, please visit:

• Voipac Downloads
• 28pins Website

Personal and commercial use of the 28Pins project documentation is completely free, just follow the Creative Commons Attribution-ShareAlike 3.0 Unported license.