Fernando
I understand that if using the PCF8575, it creates 16 additional IO port, which you then declare as P0 - P15
- this is straight forward and your code is easy to understand/follow..
What I don't yet understand is where pins 80 - 87 (used for timers, and other functions) are coming from?
(defined in setup.ino)
At first I figured pins 80 - 87 are linked to Analogue pins A0 - A14, but then I realised it cant be as this would then conflict to the functions already assigned to these pins (such as dosing pumps)- and I checked the logic to determine if pins 80-87 refer to physical pins on the Mega, but this too seems ilogical.
not sure if this is related to the other users post: viewtopic.php?f=8&t=411#p3134
..from this post it would seem that these are temporary pins that need to be assigned to "free" pins as needed?
been a long day, maybe I have it all wrong, and you can give simple explanation?