I am getting a message in the logs of my development environment that OctoPrint has detected an external heat up. How does OctoPrint do this? Should a firmware begin sending it's temp status before OctoPrint asks for it? I've noticed that if I don't then OctoPrint sends the M115 anyways.
If OctoPrint gets a temperature report without having asked for it (no ok prefixed) and also without autoreporting being enabled, it will print that out.
The reason is that if you trigger a blocking heatup from the printer controller or through an SD print this is exactly what will happen. And communication during a blocking heatup is... blocked. So OctoPrint has to detect that in order to not run into timeouts.
Could you provide a serial.log of your development environment? I might be able to tell you then what's happening and what needs to be adjusted/changed to not run into this just for temperature reports.
Ok, so don't send temp reports unless I get M105. And wait for OctoPrint to send M155 before I start auto reporting.
Or do all that but disable automatic heatup detection in OctoPrint's settings.