Displaying Power Expander Voltage on LCD

We are trying to figure out how to display battery voltages on our LCD screen using EasyCv5. We have made it display primary and back_up voltages. We would like to program it as follows:
Line 1 display primary voltage
line 2 display power expander voltage
line 2 display back_up battery voltage when button 1 is depressed.

The power expander is connected to the cortex in analog port 1. Using the print screen function it displays a reading in the terminal window. We even know to divide that value by 70 to get a fairly accurate voltage. What do we need to do to get the secondary voltage displayed on the LCD line 2? And how do we get Button 1 to change the display to back_up battery voltage?

Thank you in advance for our help!

I’m no EasyC expert, but in general, if you have a loop like this and want to switch the view using a button, you need to keep some kind of inner state - a variable. You’d then pick what to display based on that state:

  if (otherDisplay) {
    SetLCDText(1, 2, "9V=%d", NineV);
  } else {
    SetLCDText(1, 2, "Extra=%d", Back_up);

You’d then also need to switch based on the button:

  if (Button1Pressed /* I don't know how to read LCD buttons in EasyC */ ) {
    otherDisplay = !otherDisplay;
    /* add some kind of debounce, otherwise the display will keep toggling
         between the two at the speed of your control loop while you're holding the button */