DIY Projects

Beautifully minimal LED Advent wreath circuit and device

Beautifully minimal LED Advent wreath circuit and device

An “Advent wreath” is a horizontal wreath, traditionally with four candles which are lit successively to mark each of the four weeks of Advent in the liturgical calendar of some western-tradition Christian churches. Alexander Weber has produced a beautiful little electronic version which uses 4 LEDs, a coin cell, a coin cell holder, a paperclip, and an 8-bit microcontroller chip. It is light-responsive, and uses one of the LEDs in “reverse” mode as a photodiode to detect darkness. The LEDs flicker, and the number of LEDs lit at any point is cycled by briefly cutting the power. Awesome design.

Holding round-head screws for trimming

Holding round-head screws for trimming

Neil sent me this link to a cool trick for holding round-head screws while you cut the threads shorter. Cut a thin slit in a correspondingly-threaded nut, through one of the points. A rotary tool with an abrasive disk is probably a good tool for this. Then you can thread the screw in and grip the nut across the flats with pliers or a vise. Compression across the width of the slit will hold the screw firmly in place, and you can use the flat side of the nut to guide the saw.