EDIT: This Instructable has won Second prize in the 2013 Radio Shack Microcontroller Contest. Thank You to all who voted!
EDIT2: Our "Open Enigma Project" Kickstarter https://www.kickstarter.com/projects/438986934/the-open-enigma-project?ref=search is now over. Please visit www.stgeotronics.com if interested. THANK YOU for your support!
This is our very first Instructable and this step by step guide will show you how to build a fully functional electronic replica of the world famous German Enigma machine. This Arduino based Open Source project is able to encrypt & decrypt any Enigma M4 encoded message.
This first ever fully functional Open Source Enigma "exact " Replica was inspired by the Kid's Game to Arduino Enigma Machine by sketchsk3tch.
Using Charlie-plexing Multiplexing for the LEDs, this circuit with 115 light emitting diodes uses only 38 pins and the 36 push buttons use only 4 pins total thanks to properly placed resistors (and the P-Channel MOSFETs) in the keyboard loop. These 4 16-Segment displays & an LED for each keyboard button would add up quickly the total number of pins required and even the Arduino Mega would have ran out of pins without the 2 methods mentioned above....
In response to the overwhelming demand, we designed the PCB and made it available through www.stgeotronics.com. Skip to Step 10 & beyond for more info. We also offer it as a complete electronics kit & an assembled & tested complete product.