This is what I have come up with, so far.
1. When the Mega board operated with RR alone (no power on, no automode on) everything seems normal. I can ground various pins, see them changing state, reported (first the one that is grounded) and then and all 48 are reported every time there is a single change, end of case.
2. When I give "power on" (fake as it runs on virtual cs) it will run one or two times with the following messages on screen
02:57:37 Output 15 a (mm) on
02:57:19 Output 15 a (mm) off
02:56:38 Output 15 a (mm) on
02:56:38 sensor 1:28 state=1
Communication with Mega will stop after that...
You may notice that the sensor which is grounded is 28, I really do not know why it also outputs the messages like this :Output 15 a (mm) on
3. When I start both auto mode and power on, with the first try on any sensor, it will turn the power off on the rail off and the usb port communication with Mega is blocked.
In both 2 and 3 the further sensor change states are kept in buffer because if I unplug the Mega Board and re-plug it in, all previous missed reports (after the stop) are send back to the RR.
So this is the situation up to know, any clues, ideas on what to try? Can I try the sketch on a UNO with some modification? The number of digital pins is irrelevant for the moment as long we can see if this is also happens on UNO as well...