original idea for this project came from David Bakker at draailampje.nl ("draailampje" means "flip light" in Dutch) via Make: - I've modified it slightly. My kids both like to solder, so I wanted a project which my youngest could do mostly by herself.
- Batteries: http://amzn.to/2gQYk9P
- Battery holders: http://amzn.to/2enJDbT
- Switches: http://amzn.to/2gWmzpN
- 10mm LEDs: http://amzn.to/2g0AOoY
- 1.5 oz jars: http://amzn.to/2gDZjME
This assembly is mounted into the lid of a small hexagonal glass jar with hot glue. We built 20 of them in assembly-line fashion, with me acting as safety observer and occasionally suggesting that she re-solder some joints.
Operation is dumb simple; flip the light over to turn it on, back again to turn it off.
The CR2032 battery drives the LED directly - no current-limiting resistor is needed. You have to make a choice about orientation - David Bakker's original design is to have the light on when the lid is up.
The end result was really nice - she tossed a few on the mantle, put some on the dining room table, and gave a few away as gifts.
The most expensive parts of the project were the glass jars. You can get them for about $1 each if you buy a box of 24. Parts list above.