A PIR motion sensor and a string of inverters and RC delay lines light up LEDs that are inserted into some small plastic pumpkins. The string will be off as the default stage and turn on all pumpkins with a nice delay. Small movement will trigger a pseudo-random pattern, and a more constant movement will turn on the full string.
Mounted on the walkway to the front door, the unsuspecting trick-or-treater will be surprised by
This build was inspired by an article on Hack-A-Day about [Jeri's] Barbot dress in 2011. I just changed the series resistors from 2K Ohm as described in the video to 100K Ohm a get a more noticable delay and used 74AHC1G14 inverters.
I started my layout for the tiny PCBs on a paper grid similar to the perfboard/stripboard drawing paper project on Hackaday projects. I just filled a lot of cells on an Excel sheet with lowercase o's and adjusted the cell size to a square. Printing a page gave the pattern to start drawing the parts before starting to solder.
PIR Motion Sensor
From a regular Pumpkin lights chain
White LED 5mm Viewing angle 110 degree
Single Gate Schmitt Trigger Inverter