My problem is the float value "Voltage is coming on screen but when the delay time works and new reading comes the value displayed is over lapping .... i dont know to refresh the screen and display the new reading from the analog pin (voltage).
It caused by fonts design - it are transparent and do not have a background.
So if you want to display the new value in the place - you should clean it before/ The simplest method for it - to draw rectange with background color, covering the letters that you want to delete.