The Diode Clock is the first large-scale test of DDL, a universal digital logic family using only 1N4148 and 1N4007 diodes as switching elements. While simple AND/OR gates have long been constructed using diodes, I believe DDL represents the first diode-only logic circuits able to perform arbitrary logic functions. The clock is built using (46) DDL01 Hex NOR boards, comprising over 8,000 discrete components. It is the latest step in a 30 year quest to construct a computer using only diodes.
DDL has evolved over several generations to the point where complex digital logic systems are possible. In this project, I’ll explain the idea behind DDL logic and release open-source designs for the circuits and PCBs suitable for building your own clock (or a diode-only computer), as well as a simple demo circuit you can quickly build to experiment with this idea.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.