ESP-MODBUS is the official Modbus library for Espressif SoCs.


# ESP-Modbus Library ## Overview An Espressif ESP-Modbus Library (esp-modbus) is a library to support Modbus communication in the networks based on RS485, WiFi, Ethernet interfaces. The Modbus is a data communications protocol originally published by Modicon (now Schneider Electric) in 1979 for use with its programmable logic controllers (PLCs). * [ESP-Modbus component on GitHub]( This library is to be used with Espressif’s IoT Development Framework, [ESP_IDF]( The packages from this repository are uploaded to Espressif’s component repository. * [esp-modbus component in component repository]( You can add the component to your project via ` add-dependency`. More information about idf-component-manager can be found in [Espressif API guide]( or [PyPi registry]( The ESP-Modbus library can be used with ESP-IDF v4.1 and later. ESP-IDF v4.x releases include an earlier version of ESP-Modbus library inside freemodbus component. To use ESP-Modbus with these releases, users need to exclude the built-in freemodbus component from the build process, and update application components to depend on esp-modbus component instead. To exclude freemodbus component from compilation, add the following line to the project CMakeLists.txt file: ``` set(EXCLUDE_COMPONENTS freemodbus) ``` ESP-IDF v5.x and later releases do not include freemodbus component, so no extra steps are necessary when adding esp-modbus component. ## Documentation The documentation can be found on the link below: * [ESP-Modbus documentation (English)]( ## Application Examples The examples below demonstrate the ESP-Modbus library of serial, TCP ports for slave and master implementations accordingly. - [Modbus serial slave example]( - [Modbus serial master example]( - [Modbus TCP master example]( - [Modbus TCP slave example]( Please refer to the specific example for details. ## Protocol References - [Modbus Organization with protocol specifications]( ## Contributing We welcome contributions to this project in the form of bug reports, feature requests and pull requests. Issue reports and feature requests can be submitted using Github Issues: Please check if the issue has already been reported before opening a new one. Contributions in the form of pull requests should follow ESP-IDF project's [contribution guidelines]( We kindly ask developers to start a discussion on an issue before proposing large changes to the project. ## Licence ESP-Modbus project is based on [FreeMODBUS library](, Copyright (c) 2006 Christian Walter and licensed under the BSD 3-clause license. Modbus Master related code is Copyright (c) 2013 Armink and licensed under BSD 3-clause license. All original code in this repository is Copyright (c) 2016-2022 Espressif Systems (Shanghai) Co. Ltd. The project is distributed under Apache 2.0 license. See the accompanying [LICENSE file]( for a copy.


Supports all targets

License: Apache-2.0

To add this component to your project, run: add-dependency "espressif/esp-modbus^1.0.11"

or download archive


  • ESP-IDF >=4.3
  • Stats

    • Downloaded in total
      Downloaded in total 188.4k times
    • Downloaded this version
      This version: 41.2k times


    espressif/esp-modbus version: 1.0.11 |