Link to PrettyPins PDF on GitHub.


There are two ways you can power the Feather ESP32-S3, as well as other related pins.

  • USB-C port - This is used for both powering and programming the board. You can power it with any USB C cable. When USB is plugged in it will charge the Lipoly battery.
  • LiPoly connector/charger - You can plug in any 250mAh or larger 3.7/4.2V Lipoly battery into this JST 2-PH port to both power your Feather and charge the battery. The battery will charge from the USB power when USB is plugged in. If the battery is plugged in and USB is plugged in, the Feather will power itself from USB and it will charge the battery up.
  • CHG LED - When the battery is charging, the yellow CHG LED will be lit. When charging is complete, the LED will turn off. If there's no battery plugged in, the CHD LED may blink rapidly - this is expected!
  • GND - This is the common ground for all power and logic.
  • BAT - This is the positive voltage to/from the 2-pin JST jack for the optional Lipoly battery.
  • USB - This is the positive voltage to/from the USB C jack, if USB is connected.
  • EN - This is the 3.3V regulator's enable pin. It's pulled up, so connect to ground to disable the 3.3V regulator.
  • 3.3V - These pins are the output from the 3.3V regulator, they can supply 500mA peak.

ESP32-S3 WiFi Module

This is the ESP32-S3 module.

The ESP32-S3 is a highly-integrated, low-power, 2.4 GHz Wi-Fi System-on-Chip (SoC) solution that now has built-in native USB as well as some other interesting new technologies like Time of Flight distance measurements. With its state-of-the-art power and RF performance, this SoC is an ideal choice for a wide variety of application scenarios relating to the Internet of Things (IoT), wearable electronics, and smart homes.

The Feather ESP32-S3 has a dual-core 240 MHz chip, so it is comparable to
ESP32's dual-core. However, there is no Bluetooth Classic support, only
Bluetooth LE. We are super excited about the ESP32-S3's native USB which unlocks a lot of capabilities for advanced interfacing! This module comes with 8 MB flash and no PSRAM.

The 8 MB of flash is inside the module and is used for both program firmware and filesystem storage. For example, in CircuitPython, we have 4 MB set aside for program firmware (this includes two OTA option spots as well) and an approximately 3.8MB section for CircuitPython scripts and files.

BME280 Temperature, Humidity and Pressure Sensor

The Feather ESP32-S3 currently comes with only a FOOTPRINT for the BME280 sensor. It does NOT come with the actual sensor on the board.
The highlighted space is the footprint where a BME280 would go.

The Feather ESP32-S3 comes with the footprint for a BME280 Temperature, Humidity and Barometric Pressure Sensor. When populated, it is connected over I2C (at address 0x77), and provides immediate ambient weather sensing. It is rated for measuring humidity with ±3% accuracy, barometric pressure with ±1 hPa absolute accuraccy, and temperature with ±1.0°C accuracy. Because pressure changes with altitude, and the pressure measurements are so good, you can also use it as an altimeter with  ±1 meter or better accuracy!

The BME280 sensor's physical proximity to the ESP32-S3 module can cause the sensor's temperature to increase when powered on for extended periods of time.

Logic Pins

These are the logic pins that can be used to connect FeatherWings, sensors, servos, LEDs and more!

No pins are shared, and no pins are 'special' bootstrapping pins, so you can use any of them for input, or output, will pullups or pulldowns, without worry.

ESP32 chips allow for 'multiplexing' of almost all signals so it isn't like some pins can do PWM and others can. You can connect any of the available PWM channels, I2S channels, UART, I2C or SPI ports to any pin. There are some exceptions....

There are six analog pins.

  • A0 thru A5 can also be analog inputs. A0 thru A4 are on ADC2, and A5 is on ADC1.

The SPI pins are on the ESP32-S3 high-speed peripheral. You can set any pins to be the low-speed peripheral but you won't get the speedy interface!

  • SCK - This is the SPI clock pin.
  • MOSI - This is the SPI Microcontroller Out / Sensor In pin.
  • MISO - This is the SPI Microcontroller In / Sensor Out pin.

The UART interface.

  • RX - This is the UART receive pin. Connect to TX (transmit) pin on your sensor or breakout.
  • TX - This is the UART transmit pin. Connect to RX (receive) pin on your sensor or breakout.

The I2C interface. This is shared by the STEMMA QT connector.

  • SCL - This is the I2C clock pin. There is a 5k pullup on this pin.
  • SDA - This is the I2C data pin. There is a 5k pullup on this pin.
  • There is an I2C power pin for the STEMMA QT connector (and the BME280, if present), which is on by default. It is available in CircuitPython as I2C_POWER, and in Arduino as PIN_I2C_POWER. To turn it off for low power usage, set the pin to output, and set it LOW to disable.

The digital pins.

  • D5-D6, D9-D13 - These are digital pins. D5, D6, D9 and D10 are on ADC1. D11-D13 are on ADC2.

Check the ESP32-S3 datasheet or the PrettyPins diagram above for the ADC channel names for each pin if you need em!

NeoPixel and Red LED

There are two LEDs you can control in code.

  • NeoPixel LED - This addressable RGB NeoPixel LED, labeled Neo on the board, works both as a status LED (in CircuitPython and the bootloader), and can be controlled with code. It is available in CircuitPython as board.NEOPIXEL, and in Arduino as PIN_NEOPIXEL.
  • There is a NeoPixel power pin that is on by default. To disable it for low power usage, it must be pulled LOW. It is available in CircuitPython and Arduino as NEOPIXEL_POWER.
  • Red LED - This little red LED, labeled #13 on the board, is on or blinks during certain operations (such as pulsing when in the bootloader), and is controllable in code. It is available in CircuitPython as board.LED, and in Arduino as LED_BUILTIN or 13.


This JST SH 4-pin STEMMA QT connector breaks out I2C (SCL, SDA, 3.3V, GND). It allows you to connect to various breakouts and sensors with STEMMA QT connectors or to other things using assorted associated accessories. It works great with any STEMMA QT or Qwiic sensor/device. You can also use it with Grove I2C devices thanks to this handy cable.

There is an I2C power pin for the STEMMA QT connector, which is on by default. It is available in CircuitPython as I2C_POWER, and in Arduino as PIN_I2C_POWER. You can manually cut power to the QT port completely by setting GPIO 7 to an output and LOW. This will disable power to the pullup resistors and connector, for low power usage.


There are two buttons on the Feather ESP32-S3.

  • Reset button - This button restarts the board and helps enter the bootloader. You can click it once to reset the board without unplugging the USB cable or battery. Tap once, and then tap again while the NeoPixel status LED is purple to enter the UF2 bootloader (needed to load CircuitPython).
  • The RST pin is can be used to reset the board. Tie to ground manually to reset the board.
  • Boot button - This button can be read as an input in code. It is available as board.BUTTON in CircuitPython, and pin 0 in Arduino. Simply set it to be an input with a pullup. This button can also be used to put the board into ROM bootloader mode. To enter ROM bootloader mode, hold down DFU button while clicking reset button mentioned above. When in the ROM bootloader, you can upload code and query the chip using esptool.


This is the Debug TX (DB) pin. This is the hardware UART debug pin. You can connect this to a USB console cable in order to read the debug output from the ESP32 IDF. This is useful if you are writing software and need to see the low level debug output.

This is not where default Serial.print() or CircuitPython print() outputs go, because those will go through the USB port instead!

This guide was first published on Apr 20, 2022. It was last updated on 2022-04-20 14:41:15 -0400.

This page (Pinouts) was last updated on May 24, 2022.

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