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.
Guide
ATtiny 0/1/2-Series Pinout
The complete pin reference for Microchip’s modern ATtiny 0/1/2-series: true USART, SPI and I2C peripherals, and single-wire UPDI programming instead of classic ISP.
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Reference
ESP32-S3 Zero / Super Mini Pinout
The real pin reference for the ESP32-S3-Zero-style board: a coin-sized ESP32-S3 devkit sold under names like "ESP32-S3 Zero" and "ESP32-S3 Super Mini" by Waveshare and several other sellers.
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Guide
Raspberry Pi 4 Pinout
The complete 40-pin GPIO reference for the Raspberry Pi 4 Model B: 26 general-purpose pins, I2C, SPI, UART, PWM, and the exact pins you can safely reuse.
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Reference
MCP23017 16-Bit I/O Expander – Complete Guide
Add 16 fully-configurable GPIO pins to a pin-limited board over a two-wire I²C bus, with per-pin pull-ups and interrupt-on-change built in. This guide covers the pinout, I²C address selection, register map, ESP-IDF/Arduino code, and how it compares to the simpler PCF8574.
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Reference
CD74HC4067 16-Channel Analog Multiplexer – Complete Guide
A 16-position analog switch controlled by just 4 GPIO pins, turning one ADC input into sixteen. This guide covers the pinout, channel-select truth table, ESP32 wiring, ESP-IDF/Arduino code, and how it compares to the 74HC4051 and the ADS1115.
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Reference
SHT40 / SHT41 Temperature and Humidity Sensor Complete Guide
Sensirion's fourth-generation SHT4x sensors trade the SHT3x series' heater-based self-test for an ultra-low idle power budget and a slightly tighter accuracy spec. This guide covers wiring an SHT40 or SHT41 to an ESP32, real I2C addressing, and which SHT generation actually makes sense for a new project.
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Reference
ADS1115 16-Bit ADC
A precision 16-bit I2C analog-to-digital converter for when the ESP32’s own noisy 12-bit ADC is not accurate enough. Covers single-ended and differential inputs, the programmable gain amplifier, and reading a signed conversion result correctly.
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