Behind its geometric planter shell, murCO uses an ESP32-based controller and SCD40 sensor to send local CO₂, temperature, and humidity readings to Home Assistant. LEDs, optional speech, and Bluetooth proxy features make ventilation information useful without depending on a dashboard. The open-source repository and project documentation provide implementation details.
Read the build on openelab.io: A 3D-Printed Planter That Monitors Indoor CO₂
Tiny points of colored light can feel surprisingly alive when they move, fade, and sparkle independently. This project pairs an ESP32-based Adafruit board with addressable LEDs and CircuitPython, giving makers a hands-on way to build an animated display, then adjust its colors, timing, brightness, and physical form.
Read the build on cdn-learn.adafruit.com: Build an ESP32 Sparkle Motion Light
At 2.02 volts, a battery pack exposed the gap between firmware’s “protected” message and real electrical safety. This ESP-NOW RC car pairs an ESP32 controller with an ESP8266 vehicle board, then adds packet checks, acknowledgements, failsafes, pairing, and hard-won debugging lessons from actual hardware faults.
Read the build on learniot.in: Reliable ESP-NOW RC Car With ESP32 and ESP8266
Pressure-cooker whistles are easy to miss when the kitchen gets busy. This ESP32 project uses a MAX4466 microphone to count sound events, then sends a WhatsApp message through CircuitDigest Cloud when the selected count is reached. It needs careful calibration, reliable Wi-Fi, and continued supervision around the cooker.
Read the build on circuitdigest.com: Build an ESP32 Cooker Whistle Counter
On a desk or wall, SonosESP turns a 4-inch or 7-inch touchscreen and ESP32-P4 into a dedicated music remote. It browses libraries, controls speakers across rooms, shows album art and lyrics, displays weather and clocks, and receives firmware updates without being removed from its mounting.
Read the build on github.com: ESP32 Touchscreen Sonos Wall Panel