What I want to do is to hack into the camera's WiFi with an ESP8266, i.e. have it masquerade as the phone app, but I'm utterly clueless about where to start and I just hope somebody else has already done it.
There is obviously nothing sacred about the WiFi per se. I can see it in the phone's settings but that is about as far as I can get. The camera can establish connection using a QR diagram on its screen but it isn't a prerequisite. I understand the QR code has the network name and password. I have read it but it looks like gobblydegook and it is pretty clear that Olympus is going to resist me all the way.
I don't expect any joy from the phone app. It won't do anything until it is connect to a "registered camera".
I am in the process of making an intervalometer using a Arduino ProMini and a DS3231, with cable-connect to the cameras. It already has an ESP-01 but this is only used to check the RTC against the Internet during Setup, and I would rather it was better employed.
I hope somebody has already been down this road.....