50 years ago the world's first scientific pocket calculator was launched in Feb 1972 e.g. the HP-35. Celebrate 50 years of pocket calculators with homemade calculator or implementing a useful everyday formula on a small handheld device
How about a Project 14 theme of resurrecting a project that was started but never completed. That should provide a head start on the project.
Something with a microcontroller - just to narrow it down a bit.
Project featuring all chips in SOT-23 packages. Chips with different packages are prohibited or penalized. Non-chip parts (connectors, wires, breadboard, resistors, capacitors, coils, LEDs, ...) are allowed in any package. Allowed are all chips in SOT...
"Homebrew electronic instruments" is always a popular Project14 topic so it is time for another go at it.
Things like an RGB LED tester, or a unique live wire detection and indication device, or a custom inductor winder, or a remote controlled power...
Thermal printers are used for years. Most of them support RS-232 communication so it would be nice to see some project featuring these printers driven by Arduino or some other board.
Any project featuring some analog volt/ampere/other meter .
Photo source: https://uk.farnell.com/hobut/f3pam602-15v/battery-charge-meter-0-15v/dp/1015951
It could be interesting to create a low power challenge - build a circuit with a simple specific functionality, trying to achieve as low operating and sleep power as possible.
For example a push to switch on and push to switch of circuit with an LED...