ESP32: measure ambient light with the BH1750 lux sensor
Wire a BH1750 to an ESP32 over I2C and get real lux readings instead of a raw ADC number. The light sensor that works out of the box.
Make it. Wire it. Ship it.
Hands-on tutorials for ESP32, Arduino, Raspberry Pi, and Pico. The kind where you finish with a working project, not a pile of half-wired parts and a vague sense of guilt.
ESP32
Wi-Fi, BLE, dual cores. The microcontroller that ate the hobby.
Arduino
The classic. Still the right call when you just need a chip to read a sensor.
Raspberry Pi
When you want a full Linux box with GPIO. Good for dashboards, MQTT, vision.
Pico / RP2040
The cheap one. MicroPython or C. PIO is genuinely fun once you stop fighting it.
Latest tutorials
ESP32: add precision analog inputs with the ADS1115
The ESP32 ADC is noisy and 12-bit. The ADS1115 gives you 16-bit, 4-channel, differential readings over I2C for $4.
ESP32: environmental sensing with the BME680
The BME680 reads temperature, humidity, pressure, AND volatile organic compounds (VOC) from air quality, over one I2C bus.
ESP32: build a digital scale with a load cell and HX711
Turn a $8 load cell into a working digital scale with the HX711 amp and an ESP32. Calibration, tare, and the wiring that gets 1g resolution.
ESP32: push notifications with ntfy.sh, self-hosted
Send push notifications from an ESP32 to your phone with ntfy.sh. One HTTP POST, no cloud account, and the server can live on your own Raspberry Pi.
ESP32: send email alerts over SMTP, no cloud service
Send email straight from an ESP32 over SMTP with STARTTLS. Works with your own mail server or any provider, no third-party IoT API.
Arduino: build a line-following robot
A 2WD robot that follows a black electrical-tape line using three IR reflectance sensors. Bang-bang control done honestly, PID optional.
ESP32-CAM: take and send a photo on motion via ntfy
PIR sensor triggers the ESP32-CAM, which captures a JPEG and pushes it to your phone over ntfy. Self-hosted security camera, no cloud.
Arduino: a full traffic light with pedestrian button
Build a traffic light with a pedestrian crossing button using a proper state machine. The project that teaches event timing without delay().