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Sensor Projects
Learn analog and digital sensing on ESP32 — distance, environmental, and signal processing project guides.
What this category covers
Analog, digital, ultrasonic, environmental, and threshold-based sensing projects for ESP32. A practical first build is ESP32 Distance Monitoring System.
Start here: Start with a single sensor reading in Serial Monitor, then add a display or alert once values make sense.
Skills you practice
- ADC readings
- voltage-divider awareness
- digital sensors
- threshold testing
Related guides
Related categories
Learning progression
- Read analog valuesStart with ADC limits, input range, and why raw numbers need context.
- Use real sensorsPractice calibration and smoothing before building a finished monitor.
- Measure distanceUse HC-SR04-style sensing with echo-voltage caution.
- Build environment projectsMove into BME280, DHT22, or other sensors once reading patterns are understood.
Choose the right project
- Soil sensingChoose this for ADC calibration, wet/dry testing, and threshold behaviour.
- Distance sensingChoose this for timing-based sensing and echo wiring checks.
- Gesture inputChoose this for I2C events and controlled sensor placement.
- Weather sensingChoose this for BME280-style temperature, pressure, humidity, and networking.
Technical reality and troubleshooting
Limits to understand
- ESP32 sensor work begins with voltage compatibility and pin capability, not code.
- GPIO34, GPIO35, GPIO36, and GPIO39 are input-only and are useful for readings, not outputs.
- ADC sensors, I2C sensors, and pulse-timing sensors fail in different ways, so troubleshooting must match the interface.
Common failure checks
- ADC readings are noisy: check input voltage range, ground, wire length, sampling interval, and whether averaging hides real changes.
- I2C sensor missing: scan the bus, check SDA/SCL, and verify the module voltage and address.
- Digital sensor never changes: check pull-up/pull-down behaviour and confirm the pin is configured as input.
Privacy boundary
ESP32 Distance Monitoring System
Build an ESP32 HC-SR04 distance monitor with TRIG GPIO5, ECHO GPIO18 through a 10 kOhm / 20 kOhm di…
Build an APDS-9960 Gesture Control Demo
Build a technically honest ESP32 gesture demo with APDS-9960 I2C wiring, interrupt handling, LED ou…
Build a Local NEO-6M GPS Reader
Build an ESP32 NEO-6M GPS reader with UART wiring, TinyGPS++ parsing, no-fix handling, sky-view gui…
ESP32 Soil Moisture Monitor
A plant monitor that reads a capacitive soil sensor, converts raw ADC values into a moisture percen…