I built a control system to manage a gas valve for a smokehouse. I am using a 3.5" Nextion display, an Arduino Mega and it has been a blessing using the Nextion. It has been a long process but I have learned a lot about MCUs and Nextion. (Thank you Patrick)
My process is running fantastic. My design updates the Nextion global variables every 3 seconds. The Nextion status screen has a timer to display the status of the Arduino controller every second. I could change it to 3 seconds to match the Arduino code but have not.
The process runs fine for maybe 10 minutes. It turns the valve off and one perfectly. All my logging information is captured on a micro SD card so I can see what is going on when the debug mode is on. There are no surprises or runaway loops.
It is running perfect when all of a sudden the Nextion goes back to the home screen. I am testing my process with a little 5V battery. The 5V battery is run through the Arduino and the 5V is brought into a little board to power some things including the Nextion.
My gut is telling me the Nextion is going back to the home screen because of some power issue. I have swapped out my Arduino mega, relays, etc .... I have the same results.
I have 2 questions.
Is there any way to log the input voltage to the Nextion?
Does anyone have input as to why the Nextion goes back to the home screen? When this happens, the Arduino appears to be frozen while you can still click through the Nextion screens.