how to use monitor serial to wiev my data in only a line .

I would like to see my data from serial monitor that change not during scrolling but in a line thank you for help I am in a first experience .

Perhaps you need to use Serial.print() rather than Serial.println()

...R

Or, more likely, you need to use a program that understands VT100 control codes, and you need to send them, to allow overwriting the one line. The Serial Monitor app does not support overwriting the same line.