Get Started

This document is intended to help users set up the software environment for developement of applications using hardware based on the Espressif ESP32. Through a simple example we would like to illustrate how to use ESP-IDF (Espressif IoT Development Framework), including the menu based configuration, compiling the ESP-IDF and firmware download to ESP32 boards.

Introduction

ESP32 integrates Wi-Fi (2.4 GHz band) and Bluetooth 4.2 solutions on a single chip, along with dual high performance cores, Ultra Low Power co-processor and several peripherals. Powered by 40 nm technology, ESP32 provides a robust, highly integrated platform to meet the continuous demands for efficient power usage, compact design, security, high performance, and reliability.

Espressif provides the basic hardware and software resources that help application developers to build their ideas around the ESP32 series hardware. The software development framework by Espressif is intended for rapidly developing Internet-of-Things (IoT) applications, with Wi-Fi, Bluetooth, power management and several other system features.

What You Need

To develop applications for ESP32 you need:

  • PC loaded with either Windows, Linux or Mac operating system
  • Toolchain to build the Application for ESP32
  • ESP-IDF that essentially contains API for ESP32 and scripts to operate the Toolchain
  • A text editor to write programs (Projects) in C, e.g. Eclipse
  • The ESP32 board itself and a USB cable to connect it to the PC
Development of applications for ESP32

Development of applications for ESP32

Preparation of development environment consists of three steps:

  1. Setup of Toolchain
  2. Getting of ESP-IDF from GitHub
  3. Installation and configuration of Eclipse

You may skip the last step, if you prefer to use different editor.

Having environment set up, you are ready to start the most interesting part - the application development. This process may be summarized in four steps:

  1. Configuration of a Project and writing the code
  2. Compilation of the Project and linking it to build an Application
  3. Flashing (uploading) of the Application to ESP32
  4. Monitoring / debugging of the Application

See instructions below that will walk you through these steps.

Guides

If you have one of ESP32 development boards listed below, click on provided links to get you up and running.

If you have different board, move to sections below.

Setup Toolchain

Depending on your experience and preferences, you may follow standard installation process or customize your environment. Instructions immediately below are for standard installation. To set up the system your own way go to section Customized Setup of Toolchain.

Standard Setup of Toolchain

The quickest way to start development with ESP32 is by installing prebuild toolchain. Pick up your O/S below and follow provided instructions.

windows-logo linux-logo macos-logo
Windows Linux Mac OS

Note

We are using ~/esp directory to install prebuild toolchain, ESP-IDF and sample applications. You can use different directory, but need to adjust respective commands.

Once you are done with setting up the toolchain then go to section Get ESP-IDF.

Customized Setup of Toolchain

Instead of downloading binary toolchain from Espressif website (Standard Setup of Toolchain above) you may build the toolchain yourself.

If you can’t think of a reason why you need to build it yourself, then probably it’s better to stick with the binary version. However, here are some of the reasons why you might want to compile it from source:

  • if you want to customize toolchain build configuration
  • if you want to use a different GCC version (such as 4.8.5)
  • if you want to hack gcc or newlib or libstdc++
  • if you are curious and/or have time to spare
  • if you don’t trust binaries downloaded from the Internet

In any case, here are the instructions to compile the toolchain yourself.

Get ESP-IDF

Once you have the toolchain (that contains programs to compile and build the application) installed, you also need ESP32 specific API / libraries. They are provided by Espressif in ESP-IDF repository. To get it, open terminal, navigate to the directory you want to put ESP-IDF, and clone it using git clone command:

cd ~/esp
git clone --recursive https://github.com/espressif/esp-idf.git

ESP-IDF will be downloaded into ~/esp/esp-idf.

Note

Do not miss the --recursive option. If you have already cloned ESP-IDF without this option, run another command to get all the submodules:

cd ~/esp/esp-idf
git submodule update --init

Note

While cloning submodules on Windows platform, the git clone command may print some output starting ': not a valid identifier.... This is a known issue but the git clone still succeeds without any problems.

Setup Path to ESP-IDF

The toolchain programs access ESP-IDF using IDF_PATH environment variable. This variable should be set up on your PC, otherwise projects will not build. Setting may be done manually, each time PC is restarted. Another option is to set up it permanently by defining IDF_PATH in user profile. To do so, follow instructions specific to Windows , Linux and MacOS in section Add IDF_PATH to User Profile.

Start a Project

Now you are ready to prepare your application for ESP32. To start off quickly, we will use get-started/hello_world project from examples directory in IDF.

Copy get-started/hello_world to ~/esp directory:

cd ~/esp
cp -r $IDF_PATH/examples/get-started/hello_world .

You can also find a range of example projects under the examples directory in ESP-IDF. These example project directories can be copied in the same way as presented above, to begin your own projects.

Important

The esp-idf build system does not support spaces in paths to esp-idf or to projects.

Connect

You are almost there. To be able to proceed further, connect ESP32 board to PC, check under what serial port the board is visible and verify if serial communication works. If you are not sure how to do it, check instructions in section Establish Serial Connection with ESP32. Note the port number, as it will be required in the next step.

Configure

Being in terminal window, go to directory of hello_world application by typing cd ~/esp/hello_world. Then start project configuration utility menuconfig:

cd ~/esp/hello_world
make menuconfig

If previous steps have been done correctly, the following menu will be displayed:

Project configuration - Home window

Project configuration - Home window

In the menu, navigate to Serial flasher config > Default serial port to configure the serial port, where project will be loaded to. Confirm selection by pressing enter, save configuration by selecting < Save > and then exit application by selecting < Exit >.

Note

On Windows, serial ports have names like COM1. On MacOS, they start with /dev/cu.. On Linux, they start with /dev/tty. (See Establish Serial Connection with ESP32 for full details.)

Here are couple of tips on navigation and use of menuconfig:

  • 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.

Note

If you are Arch Linux user, navigate to SDK tool configuration and change the name of Python 2 interpreter from python to python2.

Build and Flash

Now you can build and flash the application. Run:

make flash

This will compile the application and all the ESP-IDF components, generate bootloader, partition table, and application binaries, and flash these binaries to your ESP32 board.

esptool.py v2.0-beta2
Flashing binaries to serial port /dev/ttyUSB0 (app at offset 0x10000)...
esptool.py v2.0-beta2
Connecting........___
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
Attaching SPI flash...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0220
Compressed 11616 bytes to 6695...
Wrote 11616 bytes (6695 compressed) at 0x00001000 in 0.1 seconds (effective 920.5 kbit/s)...
Hash of data verified.
Compressed 408096 bytes to 171625...
Wrote 408096 bytes (171625 compressed) at 0x00010000 in 3.9 seconds (effective 847.3 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 82...
Wrote 3072 bytes (82 compressed) at 0x00008000 in 0.0 seconds (effective 8297.4 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting...

If there are no issues, at the end of build process, you should see messages describing progress of loading process. Finally, the end module will be reset and “hello_world” application will start.

If you’d like to use the Eclipse IDE instead of running make, check out the Eclipse guide.

Monitor

To see if “hello_world” application is indeed running, type make monitor. This command is launching IDF Monitor application:

$ make monitor
MONITOR
--- idf_monitor on /dev/ttyUSB0 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ets Jun  8 2016 00:22:57

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun  8 2016 00:22:57
...

Several lines below, after start up and diagnostic log, you should see “Hello world!” printed out by the application.

...
Hello world!
Restarting in 10 seconds...
I (211) cpu_start: Starting scheduler on APP CPU.
Restarting in 9 seconds...
Restarting in 8 seconds...
Restarting in 7 seconds...

To exit monitor use shortcut Ctrl+]. To execute make flash and make monitor in one shoot type make flash monitor. Check section IDF Monitor for handy shortcuts and more details on using this application.