It is aimed to run OPC UA server on ESP32 board (xtensa toolchain). The information model is handled under models.c/h file. It contains a temperature sensor(DHT22) read port 4, a callback method to call ESP32-WROOM on board LED and 2 relays, which can be controlled as OPCUA objects.

On Board LED : GPIO 2
DHT22 Sensor : GPIO 4
RELAY 0      : GPIO 32
RELAY 1      : GPIO 33

It is tested by UAExpert and also Matrikon Mobile IOS OPC UA Client. So if you face any problems with other clients please let me know.


Getting Started

A more detailed information can be found here: Selftronics

It is required to have locally configured ESP-IDF.

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 want to dive into OPC UA part, it is advised to 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. You can follow this long but useful thread to gain more knowledge about open62541's FreeRTOS compatibility.
  • More about OPC UA stack: Open62541


Type of connection, Wi-Fi SSID, Wi-fi password and static ip configuration can be set through esp-idf's menuconfig tool. Beware that static ip is only supported for ethernet connection for now. To set these configurations navigate to "Connection configuration" in the configuration menu. To launch the configuration menu run the command. menuconfig