Build a simple web server on an ESP8266 module to show a temperature reading on a local web page, with a technical note on voltage compatibility between Arduino and the module.
Two ways to measure voltage with Arduino: direct measurement up to 5V, and a voltage divider for higher voltages, with the full calculation formulas.
A practical guide to wiring the MQ-2 gas sensor to Arduino for detecting flammable gases and smoke, with a safety note about the sensor heating up during operation.
Build an electronic radar project with Arduino using the HC-SR04 ultrasonic sensor and a servo motor, visualizing the results on your computer with Processing.