New wrinkle. Today I got a white screen in the middle of a drain.
Could you try making a simple test program that accesses the display but never actually starts any pumps? Then start and restart and restart it many times until you either see a white screen or are confident the issue isn't happening. If the latter, now change the program to start one of the pumps and do the repeating test, see if it occurs.
I can run it without the 24volts energized. But I have a simulator built that has everything but the pumps and it has never given me a white screen.
Is the 5V a totally separate supply, or is it running from a regulator off the 24V source?
I have 2 different industrial power supplies from PULS one is 24vdc and the other is 5vdc.
Also, I'm curious if this white screen is happening because the Arduino is resetting, or if it's happening in the middle of program execution. If you have a spare pin on the Arduino, could you set up an LED that's enabled at the very start of the sketch, and then gets turned off once the main loop is underway? That might help diagnose if it's a full glitch/restart or something else.
Negative. When the white screen happens the pumps keep running. I can even push the abort or mode buttons on the screen even though I can not see them and they respond appropriately. . Also there is a separate safety relay that energizes the relay card during setup as the relay card is active low.
So I think it is something else.
Finally...if the second test program described above (run screen and one pump) runs without incident, but the full program has this issue sometimes, I'd start to suspect the program is running out of RAM.
Well only one pump runs at any given time, but I could do something of this nature, however the mid cycle whiteout has me scratching my head.