ESP8266 A0

A0 / TOUT

Use with care - Fine for many uses, but check the warnings below first.

What A0 can do

ADC1 analog input (works while Wi-Fi is active)

Warnings for A0

Input only

This pin has no output driver or internal pull resistors. Use only as a digital/analog input.

ADC is 0 to 1.0 V

The ESP8266 analog input reads 0 to 1.0 V on the bare module, not 0 to 3.3 V. Feeding it 3.3 V directly damages it. Dev boards fit an onboard divider, so check your board before wiring anything to it.

Open the interactive ESP8266 pinout →

All ESP8266 pins

GPIO0 · GPIO1 · GPIO2 · GPIO3 · GPIO4 · GPIO5 · GPIO6 · GPIO7 · GPIO8 · GPIO9 · GPIO10 · GPIO11 · GPIO12 · GPIO13 · GPIO14 · GPIO15 · GPIO16 · A0

ESP32 Pinout Studio - free interactive pinout reference. Pin data generated from KiCad's own stock symbol and footprint libraries (Espressif publishes no ESP8266 KiCad data). esp32pin.com