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
"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...
Anything that helps in your home lab, from custom lighting, access system, storage management etc. to measurement tools and their additions, power supplies, loads, DMM accessories, useful cabling etc.
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...
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...
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.
Currently there are many MCUs and boards supporing Bluetooth including very cheap boards. It would be nice to projects featuring this low-distance communication use cases in some projects.