Thank you very much floresta !
It works very well.
For RPM i just wrote :
int RPM=rpm;
lcd.setCursor(10,2);
lcd.print(RPM);
if ( RPM < 1000) lcd.print(' ');
and for the PWM pulse i wrote :
lcd.setCursor(0,0);
lcd.print(potValue);
if ( potValue < 100 ) lcd.print(' ');
Thank you !