Guides
Pinouts. Tutorials. Answers.
Chip and board pinouts, plus sensor and module reference guides: real GPIO tables, real specifications, and working code for each one.
Reference
Seeed Studio XIAO nRF52840 Pinout
This site's first non-Espressif board: Nordic's nRF52840 Bluetooth Low Energy SoC on Seeed's thumbnail-sized XIAO carrier, with no Wi-Fi radio at all.
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Reference
HC-SR04 Ultrasonic Distance Sensor
A cheap trigger/echo distance sensor for parking aids, water-level monitors and obstacle-avoiding robots. Covers the 5V echo pin that can damage a 3.3V-only ESP32 GPIO, and the safe ways to level-shift it.
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Reference
BME280 Temperature, Humidity & Pressure Sensor
A combined environmental sensor that reads temperature, humidity and barometric pressure from one I2C chip. Covers the BME280 vs BMP280 mislabeling trap, the calibration/compensation maths, and estimating altitude from pressure.
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ESP32-S3-CAM-OVxxxx Pinout (Waveshare)
The complete pin reference for the Waveshare ESP32-S3-CAM-OVxxxx: camera, microSD, audio, display, I2C and UART connectors, the I/O expander and how to program it.
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Reference
ESP32-S3-DevKitC-1 Pinout (N8R2 and N16R8)
The real pin reference for the ESP32-S3-DevKitC-1 with 44 pins and two USB ports: what N8R2 and N16R8 mean, which pins you can't use, the strapping pins and how to program it.
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Reference
AI-C3 Pinout
The complete pin reference for the AI-C3: a compact ESP32-C3-MINI-1 board with two USB-C ports, an RGB LED and 15 GPIOs.
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Reference
The Complete Guide to the 1.28-Inch GC9A01 Round TFT Display Module
A 240x240 round IPS display driven by the GC9A01 controller over SPI, ideal for clocks, gauges and wearables. This guide covers the pinout, ESP32 wiring, and example code with both Adafruit_GC9A01A and TFT_eSPI.
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