// the find
cmbahadir/opcua-server
Simple, portable and maybe the cheapest OPC UA server
An OPC UA server running on an ESP32 microcontroller, built on top of the open62541 library. Targets hobbyists and industrial IoT tinkerers who want a cheap (~$10 hardware) OPC UA endpoint for connecting sensors or PLCs to SCADA systems without buying a commercial gateway.
Runs on commodity ESP32 hardware with Ethernet (the EVB board), making it genuinely the cheapest OPC UA server you can build. Uses open62541, a well-tested and spec-compliant OPC UA stack, so the protocol implementation isn't home-rolled. The Python ServerConfigurator handles provisioning over BLE/Wi-Fi using protobuf, which is a reasonable choice for embedded config. Pre-built firmware binaries mean you can flash and evaluate without setting up the full esp-idf toolchain.
Dead since December 2020 — no commits, no issues addressed, 5 stars. The hardcoded provisioning password 'abcd1234' is documented in the README and not overridable at runtime, which is a real problem for anything beyond a desk demo. Static IP is only supported over Ethernet; Wi-Fi is DHCP-only, which is awkward for anything that needs a stable address. The README itself says not to use this in production, which tells you exactly where the ceiling is.