Which ESP32 pins are input-only?

Pins GPIO 34, 35, 36 (VP) and 39 (VN) are input-only. They have no internal pull-up or pull-down resistors and cannot be used as outputs.

Which pins should I avoid on ESP32?

Avoid GPIO 6–11 (connected to internal SPI flash). GPIO 0, 2, 12, and 15 have boot-mode functions and must be in specific states during reset. Use them with caution.

How many ADC channels does the ESP32 have?

The ESP32 has two ADC units: ADC1 (GPIOs 32–39, usable while WiFi is active) and ADC2 (GPIOs 0,2,4,12–15,25–27, cannot be used while WiFi is active).

ESP32 Pinout Reference

Complete ESP32 WROOM-32 pinout with GPIO, ADC, SPI, I2C, UART pins.

PowerGPIOAnalog/ADCSpecial/ReservedGND

ESP32 WROOM-32 / DevKitC — 38-pin layout reference. Click any pin for details.

ESP32 pin reference at your fingertips

Find the right pin for I2C, SPI, UART, ADC, DAC, or touch sensing. Filter by type or search by function name. Click any pin for full alternate function details.

Frequently asked questions

Which ESP32 pins are input-only?: Pins GPIO 34, 35, 36 (VP) and 39 (VN) are input-only. They have no internal pull-up or pull-down resistors and cannot be used as outputs.
Which pins should I avoid on ESP32?: Avoid GPIO 6–11 (connected to internal SPI flash). GPIO 0, 2, 12, and 15 have boot-mode functions and must be in specific states during reset. Use them with caution.
How many ADC channels does the ESP32 have?: The ESP32 has two ADC units: ADC1 (GPIOs 32–39, usable while WiFi is active) and ADC2 (GPIOs 0,2,4,12–15,25–27, cannot be used while WiFi is active).

ESP32 pin reference at your fingertips

Frequently asked questions

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