https://codecircuits.com/tags/esp32/Recent content in ESP32 on Code CircuitsHugo -- gohugo.ioencontact@codecircuits.com (Luan Pham)contact@codecircuits.com (Luan Pham)Copyright © 2019–2026, CodeCircuitsThu, 10 Sep 2026 00:00:00 +0000https://codecircuits.com/post/esp32-temperature-moisture-mqtt/Thu, 10 Sep 2026 00:00:00 +0000contact@codecircuits.com (Luan Pham)https://codecircuits.com/post/esp32-temperature-moisture-mqtt/<p>An ESP32, a few sensors, and MQTT are enough to build a useful monitoring device for a home, greenhouse, or small IoT system. In this project, the ESP32 reads temperature, air humidity, and soil moisture, then publishes the measurements to an MQTT broker over Wi-Fi.</p> <p>The same architecture can later be extended with dashboards, alerts, data storage, or automatic irrigation.</p> <h2 id="what-we-will-build">What we will build</h2> <p>The device will:</p> <ul> <li>Connect to a Wi-Fi network</li> <li>Read temperature and air humidity from a DHT22 sensor</li> <li>Read soil moisture from an analog capacitive sensor</li> <li>Publish measurements as a JSON message over MQTT</li> <li>Reconnect automatically when Wi-Fi or MQTT is temporarily unavailable</li> </ul> <p>The data will be published to:</p>