Try making a double led dice with 14 leds driven only by 4 available pins of an Atmel Attiny13a. I did it, and it worked: 14 leds can be driven by a technique called charlieplexing when not many microcontroller pins are available. This technique...

This DB25 F breakout board has been made to solve a simple problem. To connect different modules in a modular model railroad . The schematic for this d-subminiature female board is very simple: After making a printed circuit board design and...

This S88 decoder model railroad block occupancy detector can be used to automate your model railroad with software running on your computer. The schematic has been based on traditional S88 block detectors with a 4014B shift register with one major...

This tiny DCC decoder has been made to drive 8 leds. Instead of using a more expensive turnout decoder this may be a nice alternative. The DCC decoders brain is an Atmel Attiny24A microcontroller. The microcontroller samples the DCC track signal...