AArduino ATmega328p extra mini board.

A smallest version of arduino minimal board.

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Many other boards are huge.
Here is a very tiny arduino board.
After you'r polished the project enough, time to pack it.
Only 12.5mm X 25.5mm in size!
Can be flashed with arduino bootloader before or after soldering.

All pins are exposed on the back-board.
22 pads plus serial and additional power via 1.27mm pin header.

Version 0.9 is a complete version for now.
Unlit bug being found.
Free for privet use.


complete for jlpcb

7-Zip - 14.49 kB - 07/16/2023 at 21:09


complete for pcbway tested.

x-zip-compressed - 26.86 kB - 07/16/2023 at 21:09


  • 1 × ATmega328p-au, TQFP
  • 1 × 16mHz quartz, 5.0x3.2mm.
  • 1 × Programming pin header, 5 pins, P1.27.
  • 11 × Some Rs, Cs and LEDs, 0805. About 11 PCs. See schematic.

Enjoy this project?



Matt wrote 07/17/2023 at 16:16 point

Looks cool and I can think of a few ways I'd use this. The pin labels on the back or ambiguous though--not obvious which label belongs to which pad.

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Sziklai wrote 07/18/2023 at 21:43 point

Sad to hear and thank you for feedback!!!

Ive added the last photo. Please take a look, that's why labels are looking strange.

When someone solder a pin header he'll see only half of labels.

There is another way to remember:

Clockwise from six while bottom view -> PWR, D2->D13, A0->A7, GND. That's all. Should be quite simple.

(Answer why board is so overloaded with routes and vias. lol that's why).

Thank you.

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