Penxzyl: Arduino 3-axis Brush Plotter

Made by Guiye / Art / Robotics / Upcycling

About the project

A pen plotter adapted with a brush to paint in oil.

Project info

Difficulty: Moderate

Platforms: Adafruit, Apple, Arduino

Estimated time: 1 day

License: GNU General Public License, version 3 or later (GPL3+)

Items used in this project

Hardware components

	Wire Strippers	x 1
	MINI STEPPING MOTOR BOARD	x 2
	MINI BREADBOARD MIXED COLOURS	x 4
	BRUSHED RACK PANEL 1U	x 1
	9g micro servo (1.6kg)	x 1
	Motor Shield V2.0	x 1
	Bluno MEGA 2560	x 1

Software apps and online services

	The Processing Foundation Processing
	Inkscape
	Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

x 1

Story

PENXZYL is an artistic-electronic project. It is a plotter that paints in oil. It is an improved version of my previous 2-axis pen plotter: https://vimeo.com/124412245.

Among other improvements, I added the Z axis and instead of using a fiber, I use a brush and oil containers. It is manufactured with two motors of recycled DVD recorders, a servo, an Arduino Mega 2560, and an Adafruit Motor Shield. From a computer, the drawing data is sent in G-code, which is interpreted by the boards, moving the motors according to the coordinates and generating the drawings.

;

1 / 4

Schematics, diagrams and documents

PENXZYL

Code

PENXZYL_Brush_Plotter.ino

/* 
 Mini CNC Brush Plotter firmware, based in TinyCNC https://github.com/MakerBlock/TinyCNC-Sketches
 Send GCODE to this Sketch using gctrl.pde https://github.com/damellis/gctrl
 Convert SVG to GCODE with MakerBot Unicorn plugin for Inkscape available here https://github.com/martymcguire/inkscape-unicorn
 More information about the Mini CNC Plotter here (german, sorry): http://www.makerblog.at/2015/02/projekt-mini-cnc-plotter-aus-alten-cddvd-laufwerken/
  */

#include <Servo.h>
#include <AFMotor.h>

#define LINE_BUFFER_LENGTH 512


char STEP = MICROSTEP ;


// Servo position for Up and Down 
const int penZUp = 15;
const int penZDown = 120;

// Servo on PWM pin 10
const int penServoPin = 10;

// Should be right for DVD steppers, but is not too important here
const int stepsPerRevolution = 20; 

// create servo object to control a servo 
Servo penServo;  

// Initialize steppers for X- and Y-axis using this Arduino pins for the L293D H-bridge
AF_Stepper myStepperY(stepsPerRevolution,1);            
AF_Stepper myStepperX(stepsPerRevolution,2);  

/* Structures, global variables    */
struct point { 
  float x; 
  float y; 
  float z; 
};

// Current position of plothead
struct point actuatorPos;

//  Drawing settings, should be OK
float StepInc = 0;
int StepDelay = 1;  // 
int LineDelay = 1;  //
int penDelay = 50;  //

// Motor steps to go 1 millimeter.
// Use test sketch to go 100 steps. Measure the length of line. 
// Calculate steps per mm. Enter here.
float StepsPerMillimeterX = 100.0; //
float StepsPerMillimeterY = 100.0; //

// Drawing robot limits, in mm
// OK to start with. Could go up to 50 mm if calibrated well. 
float Xmin = 0;
float Xmax = 40; 
float Ymin = 0;
float Ymax = 40; 
float Zmin = 0;
float Zmax = 1;

float Xpos = Xmin;
float Ypos = Ymin;
float Zpos = Zmax; 

// Set to true to get debug output.
boolean verbose = false;

//  Needs to interpret 
//  G1 for moving
//  G4 P300 (wait 150ms)
//  M300 S30 (pen down)
//  M300 S50 (pen up)
//  Discard anything with a (
//  Discard any other command!

/**********************
 * void setup() - Initialisations
 ***********************/
void setup() {
  //  Setup
  
  Serial.begin( 9600 );
  
  penServo.attach(penServoPin);
  penServo.write(penZUp);
  delay(100);

  // Decrease if necessary
  myStepperX.setSpeed(500);  //

  myStepperY.setSpeed(500);  //
  

  //  Set & move to initial default position
  // TBD

  //  Notifications!!!
  Serial.println("Mini CNC Plotter alive and kicking!");
  Serial.print("X range is from "); 
  Serial.print(Xmin); 
  Serial.print(" to "); 
  Serial.print(Xmax); 
  Serial.println(" mm."); 
  Serial.print("Y range is from "); 
  Serial.print(Ymin); 
  Serial.print(" to "); 
  Serial.print(Ymax); 
  Serial.println(" mm."); 
}

/**********************
 * void loop() - Main loop
 ***********************/
void loop() 
{
  
  delay(50); 
  char line[ LINE_BUFFER_LENGTH ];
  char c;
  int lineIndex;
  bool lineIsComment, lineSemiColon;

  lineIndex = 0;
  lineSemiColon = false;
  lineIsComment = false;

  while (1) {

    // Serial reception - Mostly from Grbl, added semicolon support
    while ( Serial.available()>0 ) {
      c = Serial.read();
      if (( c == '\n') || (c == '\r') ) {             // End of line reached
        if ( lineIndex > 0 ) {                        // Line is complete. Then execute!
          line[ lineIndex ] = '\0';                   // Terminate string
          if (verbose) { 
            Serial.print( "Received : "); 
            Serial.println( line ); 
          }
          processIncomingLine( line, lineIndex );
          lineIndex = 0;
        } 
        else { 
          // Empty or comment line. Skip block.
        }
        lineIsComment = false;
        lineSemiColon = false;
        Serial.println("ok");    
      } 
      else {
        if ( (lineIsComment) || (lineSemiColon) ) {   // Throw away all comment characters
          if ( c == ')' )  lineIsComment = false;     // End of comment. Resume line.
        } 
        else {
          if ( c <= ' ' ) {                           // Throw away whitepace and control characters
          } 
          else if ( c == '/' ) {                    // Block delete not supported. Ignore character.
          } 
          else if ( c == '(' ) {                    // Enable comments flag and ignore all characters until ')' or EOL.
            lineIsComment = true;
          } 
          else if ( c == ';' ) {
            lineSemiColon = true;
          } 
          else if ( lineIndex >= LINE_BUFFER_LENGTH-1 ) {
            Serial.println( "ERROR - lineBuffer overflow" );
            lineIsComment = false;
            lineSemiColon = false;
          } 
          else if ( c >= 'a' && c <= 'z' ) {        // Upcase lowercase
            line[ lineIndex++ ] = c-'a'+'A';
          } 
          else {
            line[ lineIndex++ ] = c;
          }
        }
      }
    }
  }
}

void processIncomingLine( char* line, int charNB ) {
  int currentIndex = 0;
  char buffer[ 64 ];                                 // Hope that 64 is enough for 1 parameter
  struct point newPos;

  newPos.x = 0.0;
  newPos.y = 0.0;

  //  Needs to interpret 
  //  G1 for moving
  //  G4 P300 (wait 150ms)
  //  G1 X60 Y30
  //  G1 X30 Y50
  //  M300 S30 (pen down)
  //  M300 S50 (pen up)
  //  Discard anything with a (
  //  Discard any other command!

  while( currentIndex < charNB ) {
    switch ( line[ currentIndex++ ] ) {              // Select command, if any
    case 'U':
      penUp(); 
      break;
    case 'D':
      penDown(); 
      break;
    case 'G':
      buffer[0] = line[ currentIndex++ ];          // /!\ Dirty - Only works with 2 digit commands
      //      buffer[1] = line[ currentIndex++ ];
      //      buffer[2] = '\0';
      buffer[1] = '\0';

      switch ( atoi( buffer ) ){                   // Select G command
      case 0:                                   // G00 & G01 - Movement or fast movement. Same here
      case 1:
        // /!\ Dirty - Suppose that X is before Y
        char* indexX = strchr( line+currentIndex, 'X' );  // Get X/Y position in the string (if any)
        char* indexY = strchr( line+currentIndex, 'Y' );
        if ( indexY <= 0 ) {
          newPos.x = atof( indexX + 1); 
          newPos.y = actuatorPos.y;
        } 
        else if ( indexX <= 0 ) {
          newPos.y = atof( indexY + 1);
          newPos.x = actuatorPos.x;
        } 
        else {
          newPos.y = atof( indexY + 1);
          indexY = '\0';
          newPos.x = atof( indexX + 1);
        }
        drawLine(newPos.x, newPos.y );
        //        Serial.println("ok");
        actuatorPos.x = newPos.x;
        actuatorPos.y = newPos.y;
        break;
      }
      break;
    case 'M':
      buffer[0] = line[ currentIndex++ ];        // /!\ Dirty - Only works with 3 digit commands
      buffer[1] = line[ currentIndex++ ];
      buffer[2] = line[ currentIndex++ ];
      buffer[3] = '\0';
      switch ( atoi( buffer ) ){
      case 300:
        {
          char* indexS = strchr( line+currentIndex, 'S' );
          float Spos = atof( indexS + 1);
          //         Serial.println("ok");
          if (Spos == 120) { 
            penDown(); 
          }
          if (Spos == 15) { 
            penUp(); 
          }
          break;
        }
      case 114:                                // M114 - Repport position
        Serial.print( "Absolute position : X = " );
        Serial.print( actuatorPos.x );
        Serial.print( "  -  Y = " );
        Serial.println( actuatorPos.y );
        break;
      default:
        Serial.print( "Command not recognized : M");
        Serial.println( buffer );
      }
    }
  }



}


/*********************************
 * Draw a line from (x0;y0) to (x1;y1). 
 * Bresenham algo from https://www.marginallyclever.com/blog/2013/08/how-to-build-an-2-axis-arduino-cnc-gcode-interpreter/
 * int (x1;y1) : Starting coordinates
 * int (x2;y2) : Ending coordinates
 **********************************/
void drawLine(float x1, float y1) {

  if (verbose)
  {
    Serial.print("fx1, fy1: ");
    Serial.print(x1);
    Serial.print(",");
    Serial.print(y1);
    Serial.println("");
  }  

  //  Bring instructions within limits
  if (x1 >= Xmax) { 
    x1 = Xmax; 
  }
  if (x1 <= Xmin) { 
    x1 = Xmin; 
  }
  if (y1 >= Ymax) { 
    y1 = Ymax; 
  }
  if (y1 <= Ymin) { 
    y1 = Ymin; 
  }

  if (verbose)
  {
    Serial.print("Xpos, Ypos: ");
    Serial.print(Xpos);
    Serial.print(",");
    Serial.print(Ypos);
    Serial.println("");
  }

  if (verbose)
  {
    Serial.print("x1, y1: ");
    Serial.print(x1);
    Serial.print(",");
    Serial.print(y1);
    Serial.println("");
  }

  //  Convert coordinates to steps
  x1 = (int)(x1*StepsPerMillimeterX);
  y1 = (int)(y1*StepsPerMillimeterY);
  float x0 = Xpos;
  float y0 = Ypos;

  //  Let's find out the change for the coordinates
  long dx = abs(x1-x0);
  long dy = abs(y1-y0);
  int sx = x0<x1 ? StepInc : -StepInc;
  int sy = y0<y1 ? StepInc : -StepInc;

  long i;
  long over = 0;

  if (dx > dy) {
    for (i=0; i<dx; ++i) {
      myStepperX.onestep(sx,MICROSTEP);
      over+=dy;
      if (over>=dx) {
        over-=dx;
        myStepperY.onestep(sy,MICROSTEP);
      }
    delay(StepDelay);
    }
  }
  else {
    for (i=0; i<dy; ++i) {
      myStepperY.onestep(sy,MICROSTEP);
      over+=dx;
      if (over>=dy) {
        over-=dy;
        myStepperX.onestep(sx,MICROSTEP);
      }
      delay(StepDelay);
    }    
  }

  if (verbose)
  {
    Serial.print("dx, dy:");
    Serial.print(dx);
    Serial.print(",");
    Serial.print(dy);
    Serial.println("");
  }

  if (verbose)
  {
    Serial.print("Going to (");
    Serial.print(x0);
    Serial.print(",");
    Serial.print(y0);
    Serial.println(")");
  }

  //  Delay before any next lines are submitted
  delay(LineDelay);
  //  Update the positions
  Xpos = x1;
  Ypos = y1;
}

//  Raises pen
void penUp() { 
  penServo.write(penZUp); 
  delay(penDelay); 
  Zpos=Zmax; 
  digitalWrite(15, LOW);
    digitalWrite(16, HIGH);
  if (verbose) { 
    Serial.println("Pen up!"); 
    
  } 
}
//  Lowers pen
void penDown() { 
  penServo.write(penZDown); 
  delay(penDelay); 
  Zpos=Zmin; 
  digitalWrite(15, HIGH);
    digitalWrite(16, LOW);
  if (verbose) { 
    Serial.println("Pen down."); 
    
    
  } 
}

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Penxzyl: Arduino 3-axis Brush Plotter

About the project

Project info

Items used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics, diagrams and documents

PENXZYL

Code

PENXZYL_Brush_Plotter.ino

Credits

Guiye

Leave your feedback...

Shop

Project Hub

Video

Blog

Shop home

3D printing

Single Board Computers

Development kits

Sensors

Internet of things

Robotics

Accessories

Product of the Week

Electromaker Educator

The Electromaker Show

The Electromaker Podcast

Penxzyl: Arduino 3-axis Brush Plotter

About the project

Project info

Items used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics, diagrams and documents

PENXZYL

Code

PENXZYL_Brush_Plotter.ino

Credits

Guiye

Leave your feedback...

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