Circuit cookbook

Start with a complete example, inspect its connections, then change one part or wire at a time. Every source below is in the repository. Open the gallery for the larger diagrams.

1. 01

   Button-controlled LED

   A switch completes a 5 V path through a 330 Ω resistor and LED.

   Ruby sourceGenerated diagram

2. 02

   NE555 LED blinker

   Timing resistors and capacitors surround a 555 timer and resistor-limited LED.

   Ruby sourceGenerated diagram

3. 03

   Arduino Uno output

   An offboard Uno drives an LED through a current-limiting resistor.

   Ruby sourceGenerated diagram

4. 04

   Four LED branches

   A Ruby loop repeats four independent resistor and LED paths.

   Ruby sourceGenerated diagram

5. 05

   RP2040 fermentation logger

   A full breadboard connects an RP2040 module, OLED, two SHT31 sensors, switches, and infrared modules in separate wire layers.

   Ruby sourceLayered diagram

6. 06

   Declarative LED in YAML

   A mini-board LED circuit with supply, nets, wire, and connection expectations expressed as data.

   YAML sourceCode and net output

7. 07

   The same LED circuit in TOML

   The YAML circuit above written with TOML tables, with the same board and connections.

   TOML sourceCompare the YAML output

8. 08

   74HC595 LED sequencer

   An Uno feeds a shift register; four outputs each drive a resistor and LED.

   Ruby sourceGenerated diagram

9. 09

   Light-activated buzzer

   A photoresistor and adjustable threshold drive a transistor-switched active buzzer.

   Ruby sourceGenerated diagram

10. 10

    Two-button AND gate

    Two button inputs and pull-down resistors feed a 74HC08 gate and LED.

    Ruby sourceGenerated diagram