Can ignition connect to microcomputer like STM32 and Raspberry Pi?

[nminchin]

You can run node red on a rpi and talk to the gpio ports, and node red can communicate these to Ignition.

Node-RED Module

As kevin pointed out Node-Red does have a OPC Server node. There is a stripped down version of the server but the above gives you more features to expand later on and it has more examples for you to follow. You could also use MQTT I've used both methods, For what you are doing, its down to which road you think will be easier. I think MQTT may need a little bit more set up in ignition, Vs telling ignition what IP address to discover the OPC server. This is assuming your node red device …

This post has the links to the Ignition nodes doco

And here is the ignition module

GitHub - IgnitionModuleDevelopmentCommunity/IgnitionNode-RED: Adds support for Node-RED