nano_esp32.md

Arduino Nano ESP32

Board

• FQBN: arduino:esp32:nano_nora
• MCU: ESP32-S3
• Operating voltage: 3.3V (all GPIO)

I2C

• SDA: A4 (default)
• SCL: A5 (default)
• Wire.begin() uses these by default
• All STEMMA QT sensors + OLED share this bus
• STEMMA QT breakouts have built-in 10K pull-ups — do NOT add external pull-ups

ADC (for MiCS5524)

• 12-bit resolution (0–4095 → 0–3.3V)
• ADC1 (A0–A7): Always available, even with WiFi
• ADC2: Unavailable when WiFi is active — avoid for sensors
• analogReadMilliVolts(pin) for calibrated mV readings

WiFi

• ESP32-S3 has built-in WiFi (802.11 b/g/n)
• Relevant for P2 dashboard feature
• Remember: ADC2 pins stop working when WiFi is on