Clearing the terminal screen?

Question

I'm reading data from 9 different sensors for my robot and I need to display them all steadily, in the same window so I can compare the values and see if any of the readings is off.

The problem I'm having with both Serial.print and lcd.print is that the values are constantly moving and I can't really have a good look at them while moving the robot.

I was thinking to call something like Serial.clear() before displaying anything else and that would just keep things steady and in one place, changing only the values.

From what I found so far, Serial.print(17,BYTE) for instance is no longer supported (Calling the ESC key).

So...for those with a bit more Arduino experience...what is the proper way to do this?

Answer 1

Another kick at the can:

void setup(){     /*123456789 123456789 123456789 123456789 123*/
  String newRow="\n|________________________________________";
  String scrSiz="\n|\n|\n|\n|\n|\n|\n|\n|\n|\t";
  Serial.begin(115200);  
       // this baudrate should not have flicker but it does as seen when
       // the persistence of vision threshold is insufficiently exceeded
       // 115200 baud should display ~10000 cps or a char every 0.1 msec
       // each 'for' loop iteration 'should' print 65 chars. in < 7 msec
       // Serial.print() artifact inefficiencies are the flicker culprit
       // unfortunately '\r' does not render in the IDE's Serial Monitor

  Serial.print( scrSiz+"\n|_____ size screen vertically to fit _____"  );
  for(int i=0;i<30;i++){
     delay(1000); 
     Serial.print((String)scrSiz +i +"\t" + (10*i) +newRow);}
}
void loop(){}

Answer 2

ESC is the character _2_7, not _1_7. You can also try decimal 12 (aka. FF, form feed).

Note that all these special characters are not handled by the Arduino but by the program on the receiving side. So a standard Unix terminal (xterm, gnome-terminal, kterm, ...) handles a different set of control sequences then say a Windows terminal program like HTerm.

Therefore you should specify what program you are using exactly for display. After that it is possible to tell you what control characters and control sequences are usable.

Answer 3

It's not possible to clear the Serial Monitor window based on incoming serial data.

I can think of a couple of options, the simplest (and cheatiest) is to use println() with a fixed width string that you've generated that contains your sensor data.

The Arduino IDE's Serial Monitor's Autoscroll checkbox means if you persistently send the fixed width string (with 500ms delay perhaps) this will give the impression that it's updating once it gets to the bottom and starts scrolling. You could also shrink the height of the window to make it look like it only has one line.

To accomplish a fixed width string that's suitable for serial println() you'll need functions to convert your sensor values to strings, as well as pad/trim them to a persistent size. Then concatenate the values together (including separators if it makes the data easier to read)

An output of something similar to this is what i'm hinting at:

| 1.0 | 1.1 | 1.2 | 1.3 | 1.4 | 1.5 | 1.6 | 1.7 | 1.8 |

All things considered, this isn't a great solution but it would get you a result.

A far smarter idea is to build another program outside of Arduino and it's IDE that listens to the com port for sensor values sent from the Arduino. Your Arduino program will need to send a message your external program can unambiguously interpret, something like 1=0.5; where 1 = sensor ID and 0.5 = sensor value. The external program would then keep these values (1 for each sensor). The external program can then display this information in whatever way you'd like, a nice console output would be relatively easy to achieve :-)

C# has .NET's serialport class which is a pleasure to use. (most of the time!)

Python has a module called pyserial, which is also easy great.

Either language will give you much greater control over console output, should you choose to proceed this way.

Answer 4

I have found that ASCII 12 make a Form feed, that is a new page. here is a wikipedia definition

"Form feed is a page-breaking ASCII control character. It forces the printer to eject the current page and to continue printing at the top of another"

The code is

Serial.write(12);

Arduino Terminate doesn't support the character but Putty a light open source telnet client can do it

An Example of the code

void setup() {
  Serial.begin(9600);//Initializase the serial transmiter speed

}

void loop() {
    //Code tested with Putty terminal

    Serial.write(12);//ASCII for a Form feed
    Serial.println("This is the title of a new page");// your code

    delay(500);//delay for visual
    }

Answer 5

The Arduino serial monitor isn't a regular terminal so its not possible to clear the screen using standard terminal commands. I suggest using an actual terminal emulator, like Putty.

The command for clearing a terminal screen is ESC[2J

To accomplish in Arduino code:

  Serial.write(27);       // ESC command
  Serial.print("[2J");    // clear screen command
  Serial.write(27);
  Serial.print("[H");     // cursor to home command

Source:
http://www.instructables.com/id/A-Wirelessly-Controlled-Arduino-Powered-Message-B/step6/Useful-Code-Explained-Clearing-a-Serial-Terminal/

Answer 6

I made this simple function to achieve this:

void clearscreen() { 
    for(int i=0;i<10;i++) {
        Serial.println(\n\n\n\n\n\n\n\n\n\n\n\n\n);
    }
}

It works well for me in the default terminal