This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

ESP32-S2

Overview

ESP32-S2 is a highly integrated, low-power, single-core Wi-Fi Microcontroller SoC, designed to be secure and cost-effective, with a high performance and a rich set of IO capabilities. 1

The features include the following:

  • RSA-3072-based secure boot

  • AES-XTS-256-based flash encryption

  • Protected private key and device secrets from software access

  • Cryptographic accelerators for enhanced performance

  • Protection against physical fault injection attacks

  • Various peripherals:

    • 43x programmable GPIOs

    • 14x configurable capacitive touch GPIOs

    • USB OTG

    • LCD interface

    • camera interface

    • SPI

    • I2S

    • UART

    • ADC

    • DAC

    • LED PWM with up to 8 channels

System requirements

Prerequisites

Espressif HAL requires WiFi and Bluetooth binary blobs in order work. Run the command below to retrieve those files.

west blobs fetch hal_espressif

Note

It is recommended running the command above after west update.

Building & Flashing

Build and flash applications as usual (see Building an Application and Run an Application for more details).

# From the root of the zephyr repository
west build -b esp32s2_saola samples/hello_world

The usual flash target will work with the esp32s2_saola board configuration. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b esp32s2_saola samples/hello_world
west flash

Open the serial monitor using the following command:

west espressif monitor

After the board has automatically reset and booted, you should see the following message in the monitor:

***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
Hello World! esp32s2_saola

Debugging

As with much custom hardware, the ESP32 modules require patches to OpenOCD that are not upstreamed yet. Espressif maintains their own fork of the project. The custom OpenOCD can be obtained at OpenOCD ESP32

The Zephyr SDK uses a bundled version of OpenOCD by default. You can overwrite that behavior by adding the -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts> parameter when building.

Here is an example for building the Hello World application.

# From the root of the zephyr repository
west build -b esp32s2_saola samples/hello_world -- -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>
west flash

You can debug an application in the usual way. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b esp32s2_saola samples/hello_world
west debug

References

1

https://www.espressif.com/en/products/socs/esp32-s2