March 25th is Arduino Day 2023! What Should We Do for Our Annual Arduino Project Competition?

The Arduino "thing" is "ease of implementing a controller solution".

Arduino day should celebrate the best thing about Arduinos - ease of implementation.

When did you whip up a neat solution that took almost no work. That is the quintessential beauty of Arduino.

Any simple Arduino project to "make me smile".

Still on the "Green thing", what about a project - something, anything - just that the power for the Arduino must come from solar or wind or water... The power source must be a renewable one . (and safe - just to be clear) .

does a moldy cheese project count as a going green thing ? 

that depends if one can make Arduino work while in contact with that cheese...

And maybe reverse of "intentional overkill"? In time when "your next 8-bit MCU could be 32-bit", throwing more hardware at the problem instead of optimizing  and running script interpreters on MCU so one can then program them in LUA or something (not than I am against LUA language in general, but programming MCU with it seems unusual)., maybe project focused on building something usable with as little resources as possible (but using Arduino software - to not give assembly programmers among us unfair advantage) could be fun?

This sounds great! Last time we had Design for a cause. Which had many great applications of Arduino.

Going green with Arduino could be something for the environment and sustainability.. Examples-

Automatic plant watering system for garden,

Plant health monitoring

Weather station

Solar powered devices

How about "Tips and Tricks: Getting more out of Arduino" or something similar?

For instance, people could create Arduino Libraries for interesting sensors or any functionality they have not seen in a library form, and that may be helpful to others looking to create their own Arduino libraries.

Or, people could share how they handle doing multiple things with Arduino, like handling button input while simultaneously playing music or whatever.

Another example tip/trick could be how to make an Arduino sleep between button-presses to perform energy saving.

How to code or how to troubleshoot quicker could make for interesting tips/tricks project/blog.

Some of these are more software-focussed than hardware-focussed, but could be demonstrated or tied to actual projects.

Arduino projects can be everywhere. I did use Arduino projects to save my dog's life at home for almost 2.5 years. It was a true story. In another word, Arduino projects can be fun, either be practical.

tariq.ahmad  How about making Arduino think/predict/learn (ML/AI)? Arduino sure does have a lineup of hardware for that (Nano 33 BLE Sense, Nicla).

Get Started With Machine Learning on Arduino | Arduino Documentation | Arduino Documentation

Hardware - Nicla family (arduino.cc)