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OPC UA Server on ESP32

OPC UA server runnning on ESP32 board with a minimal information model to control on-board relays of ESP32-EVB development board from Olimex. Also with a temperature node reading over GPIO 4 from a DHT-22 sensor.

DHT22 Sensor : GPIO 4
RELAY 0      : GPIO 32
RELAY 1      : GPIO 33

It is tested with UAExpert and Matrikon Mobile IOS OPC UA Client. If you see any problems with other clients please open an issue.


Getting Started

Blog post with more information: Selftronics

It is required to have ESP-IDF and configured in local.

git clone --recursive <your-esp-idf-root-path>
cd <your-esp-idf-root-path>
cd <your-esp-idf-root-path>/examples/
git clone opcua-esp32
cd opcua-esp32 build

Open62541.c and open62541.h are amalgamated OPC UA C stack files. If you are interested more on the OPC UA stack, please check Open62541 project.

If you want to build open62541.c/.h/.lib from source, be sure to apply the changes in here to make it compatible with FreeRTOS and xtensa-toolchain.

  • I haven't analyzed these modifications in open62541.c/.h files, these are just a result of trial and error process, but open62541 project is still being developed to make it easier. I would suggest to follow this long but full of practical information thread to overcome the problems about compiling open62541's with FreeRTOS.

  • OPC UA stack: Open62541


Type of connection, Wi-Fi SSID, password and static ip configuration can be set through esp-idf's menuconfig tool. Connection can be configured from under "Connection configuration" on configuration menu run by executing the command: menuconfig


This project is licensed under the Mozilla Public License Version 2.0 which is inherited from Open62541 project - see the file for details.


Please do not use this project in production or in unattended systems. Users are accoutable in case of any damage.


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