Passing VAL(0-179) to OLED

Question

I´m using Spark Fun Micro Pro board 5V: https://learn.sparkfun.com/tutorials/pro-micro--fio-v3-hookup-guide/hardware-overview-pro-micro

and to that i´ve hooked a true color OLED from digole: http://www.digole.com/index.php?productID=859

I manage to get my VAL from my potentiometer on screen. But when I exceeds val "10", and then go back to lets say "9", the zero from "10" is still there. It looks like: "90" instead of "9". The problem is of course that the second (and third) number don't go away.. Im sure there is a simple way of doing this but I can't get my head around it.. I´ve tried using clearScreen but that function makes the OLED blink in a unpleasant way every time it clears... Hope you get my question, english isn't my native language, as u maybe can tell =) Thanks

void loop() 
{ 
  val = analogRead(potpin);        // reads the value of the     potentiometer (value between 0 and 1023) 
  val = map(val, 0, 1023, 0, 179);  // scale it to use it with the servo (value between 0 and 180) 
  myservo.write(val)  sets the servo position according to the scaled     value 
  mydisp.clearScreen();
  mydisp.setPrintPos(9, 6);
  mydisp.print(val);

  delay(200);  // waits for the servo to get there 
 // mydisp.clearScreen();

}

Answer 1

Instead of printing "10" or "9" etc, print "10 " or "9 ". Add an extra space at the end of what you print which overwrites the character that was there before.

mydisp.print(val);
mydisp.print("  ");

I used 2 spaces there, in case you go from 3 digits straight to 1.

Another method is to "format" the number using sprintf:

char temp[4];
sprintf(temp, "%3d", val);
mydisp.print(temp);