I'm almost too embarrassed to reply, but, I was using a float which had a value assigned by a calculation which had an unsigned int as part of the equation. For some reason the Arduino Nano just dealt with this, but the ESP32 didn't. Anyway, I've cast the unsigned int to a float in the calculation a...

What is the range of a floating point value on the ESP32, using the Arduino IDE?

I get an overflow if I have a value below zero, which I do not get if I compile the same code for a Nano for example.