Hi PeterH,
I removed the datastring bit from the last sketch, that's properbly why you couldn't see it.
In this new version I changed the pgenPreviousMicros to static unsigned long as you suggested, but to no effect, apparently. pgen is still not working.
I also added a nowMicros instead of micros() to the function, please see if I did it correctly. About millis, if it doesn't change anything I think I'll leave it like it is.
I've also added a total burn (supply burn - return burn) to each set/engine.
I'm working on getting values displayed on a 128x64 GLCD, that seems to be a not so easy task with some difficult programming. I may just get one of those new fancy color TFT displays instead. Maybe they are easier to program...
Thanks for your support.