ATmega328 symbol doesn't match

Schematic
1

I’m trying to replicate the Arduino schematic on KiCAD for practice but the symbol in KiCAD for ATMega328 doesn’t match the one on the Arduino schematic. The pins are all in different places and there is no pin 6 at all.

How can I get the symbol to match exactly?

Thanks

2

If you want it to match exactly then you will need to create your own symbol.

The symbol that the designers used for the Arduino might have been custom. What package was it created with? Can you post a link to the schematic you are trying to replicate?

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Thanks for your kind reply, here is the schematic from the Arduino site

Thanks

4

replicate the Arduino schematic on KiCAD for practice

Not exactly the required help, but as a advice I would recommend to work through the kicad tutorial first. Albeit it seems “too simple” at first glance it covers the most basic function principles of kicad. The creation of selfdefined (or starting with “self modified”) symbols is also covered in the tutorial.

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5

That schematic has a date in 2014 on it. Probably made with eagle back then. It has a creative commons license (but I’m not even sure if such drawings are copy rightable), and if the “arduino community” was nice you could find the original eagle project and convert it to KiCad. But your goal is to practice with KiCad, and the arduino is just a vehicle for that.

You can:

  1. Take a standard ATMEGA328 from KiCad’s libraries (beware QFP has different pinout from S-DIP)
  2. Place it on your schematic.
  3. Hover the mouse cursor over it (or select it, either should work) and press [Ctrl + e] to load it in the Symbol Editor
  4. In the symbol editor you can move pins around, change the size, etc.
  5. When finished, just close the symbol editor. It will prompt you whether you want to update your schematic with the modified symbol.

The “missing” pin 6 is likely due to “pin stacking”. This means that some pins (often GND and Power) are made invisible, and placed on top of other pins with the same function. It is a practice I dislike, so for my own projects, I make these pins visible again in the symbol editor.

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Symbols have a number of “options” when being created:

  1. The ATMega328 is available in different packages. Not all packages have the same pins.
  2. The location of the “connections” on a symbol is completely arbitrary. Some folks like to have the pins 1,2,3…last. Other folks like to group the pins functionally like PortA, Port B, power, gnd etc.

You will either have to create your on symbol (or modify one and save it to your personal library). Or find one that represents the package used in the Nano