The Electronics category covers practical hardware work: building circuits, wiring sensors and actuators to microcontrollers, and the small design choices that decide whether a project fits on the board you have.
Topics include:
- Microcontrollers: Arduino, ESP32, and the firmware that runs on them.
- Analog tricks: Voltage dividers, ADC sampling, and ways to read more inputs with fewer pins.
- Digital I/O: Multiplexing, shift registers, I2C and SPI peripherals.
- Power and signal: Pull-up/pull-down resistors, debouncing, decoupling caps, and the small details that separate a working circuit from a flaky one.
May 2026
May 4, 2026
4 Buttons on 1 Analog Pin: The Voltage Divider Trick for Arduino
Wire four push buttons to a single analog pin using a binary-weighted resistor ladder. Each button (and combination) produces a unique voltage the microcontroller can map back to the right key. Includes the schematic, the math, and the Arduino sketch.
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