Halloween Pumpkin Flames

Pumpkin with simulated flames

A simple and small Halloween project to simulate some flames for a pumpkin display using an Arduino Pro Mini and five LED:s with five resistors.

The aim was to make a fairly realistic flame appearance to cast some light within a plastic pumpkin for Halloween. The components are soldered straight onto the Arduino Pro Mini board and then glued at the top of the pumpkin using a glue gun.

The code was written using PlatformIO for an Arduino Pro Mini, but you can easily adjust it for probably any Arduino or similar processor.

This design is only drawing around 5-10mA per LED so it should not put any current strain on the microprocessor ports. The black electric tape is used to cover the bright led power led on the board as I did not want to remove it.

Here is the Pumpkin Flames rev 1.0 schematics (pdf) for this construction.

You can find the Arduino firmware on GitHub if you would like to build your own or make something else with simulated flames. If you build something inspired by my code I would appreciate if you write about it in the comments below.

Features

Brightness of five LED:s are independently controlled randomly in order to create a flickering effect similar to an open fire or candle flame.

Components used for this project

• 1 pcs Arduino Pro Mini board
• 3 pcs 5mm yellow LEDs (or any colour combination you like)
• 2 pcs 5mm red LEDs (or any colour combination you like)
• 3 pcs 330ohm 0.25W resistors (adjust resistances depending on actual LEDs used)
• 2 pcs 680ohm 0.25W resistors (adjust resistances depending on actual LEDs used)
• 1 pcs diode (for polarity protection)
• 1 pcs cable with 2 wires to connect to DC power
• 1 pcs 6-12V DC battery or power adaptor