Espressif IoT Development Framework

ESP-IDF is the official development framework for the ESP32 chip.

Developing With the ESP-IDF

Setting Up ESP-IDF

See setup guides for detailed instructions to set up the ESP-IDF:

• Windows Setup Guide
• Mac OS Setup Guide
• Linux Setup Guide

Finding a Project

As well as the esp-idf-template project mentioned in the setup guide, ESP-IDF comes with some example projects in the examples directory.

Once you've found the project you want to work with, change to its directory and you can configure and build it.

Configuring the Project

idf.py menuconfig

• Opens a text-based configuration menu for the project.
• Use up & down arrow keys to navigate the menu.
• Use Enter key to go into a submenu, Escape key to go out or to exit.
• Type ? to see a help screen. Enter key exits the help screen.
• Use Space key, or Y and N keys to enable (Yes) and disable (No) configuration items with checkboxes "[*]"
• Pressing ? while highlighting a configuration item displays help about that item.
• Type / to search the configuration items.

Once done configuring, press Escape multiple times to exit and say "Yes" to save the new configuration when prompted.

Compiling the Project

idf.py build

... will compile app, bootloader and generate a partition table based on the config.

Flashing the Project

When the build finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this automatically by running:

idf.py flash

This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with idf.py menuconfig.

You don't need to run idf.py build before running idf.py flash, idf.py flash will automatically rebuild anything which needs it.

Viewing Serial Output

The idf.py monitor target uses the idf_monitor tool to display serial output from the ESP32. idf_monitor also has a range of features to decode crash output and interact with the device. Check the documentation page for details.

Exit the monitor by typing Ctrl-].

To flash and monitor output in one pass, you can run:

idf.py flash monitor

Compiling & Flashing Just the App

After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:

• idf.py app - build just the app.
• idf.py app-flash - flash just the app.

idf.py app-flash will automatically rebuild the app if it needs it.

(In normal development there's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)

The Partition Table

Once you've compiled your project, the "build" directory will contain a binary file with a name like "my_app.bin". This is an ESP32 image binary that can be loaded by the bootloader.

A single ESP32's flash can contain multiple apps, as well as many different kinds of data (calibration data, filesystems, parameter storage, etc). For this reason a partition table is flashed to offset 0x8000 in the flash.

Each entry in the partition table has a name (label), type (app, data, or something else), subtype and the offset in flash where the partition is loaded.

The simplest way to use the partition table is to idf.py menuconfig and choose one of the simple predefined partition tables:

• "Single factory app, no OTA"
• "Factory app, two OTA definitions"

In both cases the factory app is flashed at offset 0x10000. If you idf.py partition_table then it will print a summary of the partition table.

For more details about partition tables and how to create custom variations, view the docs/en/api-guides/partition-tables.rst file.

Erasing Flash

The idf.py flash target does not erase the entire flash contents. However it is sometimes useful to set the device back to a totally erased state, particularly when making partition table changes or OTA app updates. To erase the entire flash, run idf.py erase_flash.

This can be combined with other targets, ie idf.py erase_flash flash will erase everything and then re-flash the new app, bootloader and partition table.

Resources

• Documentation for the latest version: https://esp-idf.readthedocs.io/. This documentation is built from the docs directory of this repository.

• The esp32.com forum is a place to ask questions and find community resources.

• Check the Issues section on github if you find a bug or have a feature request. Please check existing Issues before opening a new one.

• If you're interested in contributing to ESP-IDF, please check the Contributions Guide.