ESP32-S3 Pinout Quick Reference

ESP32-S3 Pin Tips

• GPIO 0 is the boot mode pin — avoid using it for general I/O if you want reliable flashing.
• GPIO 26-32 are typically connected to the internal SPI flash/PSRAM on modules with octal PSRAM — do not use them.
• All GPIOs support PWM output via the LEDC peripheral (up to 8 channels).
• ADC2 channels cannot be used while Wi-Fi is active. Use ADC1 channels (GPIO 1-10) for analog reads during Wi-Fi.
• Any GPIO can be configured as I2C or UART via the GPIO matrix — the defaults shown are conventions, not hardware limits.
• For the ProjectOSAI watch build, we use I2S for audio, SPI for the display, and I2C for the IMU and RTC.