Electronics projects you can build online

Build a complete watch: OLED screen, DS3231 real-time clock, navigation buttons, then the printed board that goes with it.

A lamp controlled from a virtual phone: the ESP32 serves a page, receives commands and drives the output.

A Bluetooth Low Energy beacon broadcasting its identity and a reading to nearby devices.

The finish line of a 10-project display series: from a single pixel to a colour panel driven over SPI.

A full radio link on the PMR446 band: modulation, channel, noise, demodulation and quality measurement.

Understand how a phone attaches to a cell: OFDM modulation, mobility, echoes and useful throughput.

A telemetry link with a low-Earth-orbit satellite: very long distance, low power and Doppler shift.

A standalone sensor sending a few bytes very far, very rarely, on a tiny power budget.

A light that turns itself on when the room gets dark, using a light-dependent resistor.

Three LEDs, a realistic cycle, and a clean introduction to state machines.

Drive an SG90 servo by angle, understand the signal that controls it and its current budget.

Build a simple processor from transistors and gates, to see what is really inside a chip.

Run several tasks on one board, with priorities, a message queue and a mutex.

React instantly to an external event without polling the pin in a loop.