Thanks to Morfeo Matrixx who made two great videos for the UU  

UU    Arduino UNO Upgrade using the Atmega 1284P

Arduino UNO Upgrade


A drop-in replacement for the
Atmega328P (DIP).
An easy upgrade for the UNO



Atmega1284P features:

  • Flash Memory: 128 K x 8
  • RAM: 16 K x 8
  • EEPROM: 4 K x 8
  • Two hardware UARTs.

UU Features:

  • Drop-in replacement for the Atmega328P in DIP package, not SMD
  • Built-in 16 MHz crystal.
  • Custom made male headers won't ruin the DIP socket on your UNO
  • I2C signals and analog inputs combined on A4-A5
  • 16 MHz optibootloader, supported by the newest core developed by Maniacbug, Jack Christensen and Mark Pendrith
    https://github.com/JChristensen/mighty-1284p/tree/v1.6.3, select Sleeping Beauty board
  • Assembled. No need to hand solder male headers
  • Component underside mounting eliminates hand soldering labor and reduces assembling labor cost
  • Machine soldering offers better and consistent quality than hand soldering, also the board will be washed clean.
  • Open source, license free if you make and sell it commercially.

Schematic and BOM


1) Drop-in replacement for the Atmega328P on a UNO (DIP package only), an easy upgrade
2) I2C signals available on the pins A4-A5,  no modifications required for UNO sketches
3) Custom made male headers fit a regular DIP socket without ruining it

Since I2C signals are combined with the A4 and A5 via two isolation resistors, the A4 and A5 cannot be used as digital outputs when I2C operation is enabled on the 1284P.  The A4 and A5 default to input after reset, so you don't need to initialize the A4 and A5 when I2C is enabled.

Operational Instructions:

1)  Following the installation instructions for the newest core at https://github.com/JChristensen/mighty-1284p/tree/v1.6.3,
2)  The new ArduinoIDE 1.6.8 is not tested, so use the fully tested older ArduinoIDE 1.6.3 or 1.6.5 instead if you have a problem with the 1.6.8.
3)  Invoke the IDE, in the tools menu, click the Board, then select the Sleeping Beauty 16MHz using OptiBoot.
4)  Select the correct port for ArduinoUno

5)  Now you can compile and upload your sketch.

Big thanks to Jack and Mark. This will not be possible without their contributions. 

MSRP: $14.90
We offer a 30 day money back guarantee, no questions asked.



 Drop-in replacement for the 328P
The upgrade cannot be any simpler!


Bottom View


Driving a SPI based 2.2" TFT


Driving an I2C based LCD



With Roger's sketch we tested the UU's SPI and I2C using jumper wires.
Both SPI and I2C worked flawlessly.



Arduino UNO is a registered trademark of Arduino, LLC.

UU is a trademark of EVBplus LLC