I've been using the image code generated from Github to print a picture, but there are some errors when i'm trying to upload the code.
I've changed the code text and added some comments in it.
I'm new to this environment 
Thanks everyone for helping me out 
we accidently broke our switch during soldering , so we uses pushbutton to pause
// main code
#include "pen.h"
#include "image.h"
#define imageX 392
#define imageY 504
#define Switch 7
#define pushButton 3
#define led2 5
#define led1 4
int on1 = 0;
int on2 = 0;
int dir = 0;
long pixelNum = 0;
void setup () {
pinMode (Switch, INPUT);
pinMode (pushButton, INPUT);
pinMode (led1, OUTPUT);
pinMode (led2, OUTPUT);
//Serial.begin (115200);
}
void loop () {
Pen pen;
on2 = 0;
// pause until pushbutton is pushed
while (on2 == 0)
{
// blink blue led while pausing
on2 = digitalRead (pushButton);
delay (100);
digitalWrite (led2, LOW);
delay (100);
digitalWrite (led2, HIGH);
}
for (int i=0; i<3; i++)
{
// blink green led before starting
digitalWrite (led1, HIGH);
delay (100);
digitalWrite (led1, LOW);
delay (100);
}
delay (100);
for(int i=0; i<imageY; i++)
{
for(int j=0; j<imageX; j++)
{
on2 = digitalRead (pushButton);
// if pushbutton is pressed during printing
if (on2 == 1)
{
// blink Geen and Blue leds
on2 = digitalRead (pushButton);
digitalWrite (led2, HIGH);
digitalWrite (led1, HIGH);
delay (1000);
digitalWrite (led2, HIGH);
digitalWrite (led1, HIGH);
delay (500);
while (1) {
// the loop keeps on until the pushbutton is pushed again
// blink Blue led
digitalWrite (led2, HIGH);
delay (100);
digitalWrite (led2, LOW);
delay (100);
on1 = digitalRead (Switch);
on2 = digitalRead (pushButton);
// if slide switch is on, reset the printer
// move the cnc back
if (on1 == 0)
{
digitalWrite (led1, HIGH); // led Green on
pen.accelerate (i, 1, (dir+1)%2); // the X axis in opposite direction
delay (1000);
pen.accelerate (j, 0, (dir+1)%2); // the Y axis in opposite direction
delay (500);
goto Finished;
}
// if pushbutton is pushed again
// continue to print
if (on2 == 1)
{
// blink Blue and Green leds
digitalWrite (led2, HIGH);
digitalWrite (led1, HIGH);
delay (1000);
digitalWrite (led2, LOW);
digitalWrite (led1, LOW);
delay (500);
break; // break the loop
}
}
}
digitalWrite (led2, HIGH);
// check the pixel
// if the binary is 0, dot
if(!pen.checkPixel(pixelNum)){
pen.dot ();
delay(500);
}
pen.movePixel (1, dir); // move a pixel
pixelNum++;
}
pen.accelerate (imageX, 1, (dir+1)%2); // move the X axis back
delay(500);
}
// finished
// move the cnc back to orgin spot
delay (1000);
pen.accelerate (imageX, 1, (dir+1)%2); // the X axis in opposite direction
delay (1000);
pen.accelerate (imageY, 0, (dir+1)%2); // the Y axis in opposite direction
Finished:
delay (100);
}
// pen.h
#include <Servo.h>
#include "image.h"
Servo penMotor;
// define a pen Libary for stepper motor and Servos
class Pen{
private:
//array of pins
const int motorStep[2] = {12, 10};
const int motorDir[2] = {11, 9};
//Servo penMotor;
const int ServoPin = 8;
//distance, high, low
const int high = 10; // default height
const int drop = 45; // default depth
//original: 10, 20
const int steps [2] = {10, 10};
//original 5000, 5000
const int delaytime [2] = {5000, 5000};
const int minDelay [2] = {5000, 5000};
public:
void movePixel (int, int); // moving in pixels
void accelerate (int, int, int); // moving backwards faster
void dot (); // dot functopn
int checkPixel (long); // checking if it's 0 or 1 (print or not)
// for testing
void down ();
void up ();
// initialize constructor
Pen (){
for (int i=0; i<2; i++)
{
pinMode (motorStep [i], OUTPUT);
pinMode (motorDir [i], OUTPUT);
}
penMotor.attach (ServoPin);
penMotor.write (high);
}
};
void Pen::movePixel (int motor, int dir){
for (int i=0; i<steps[motor]; i++)
{
digitalWrite (motorDir[motor], dir);
digitalWrite (motorStep[motor], LOW);
digitalWrite (motorStep[motor], HIGH);
delayMicroseconds (delaytime[motor]);
digitalWrite (motorStep[motor], LOW);
}
}
void Pen::accelerate (int Step, int motor, int dir) {
for (int i=0; i<Step*steps[motor]; i++)
{
digitalWrite (motorDir[motor], dir);
digitalWrite (motorStep[motor], LOW);
digitalWrite (motorStep[motor], HIGH);
delayMicroseconds (minDelay[motor]);
digitalWrite (motorStep[motor], LOW);
}
}
void Pen::up () {
penMotor.write (high);
}
void Pen::down () {
penMotor.write (drop);
}
void Pen::dot (){
penMotor.write (drop);
delay (100);
penMotor.write (high);
delay (100);
}
int Pen::checkPixel (long pixel) {
unsigned long byteNum = pixel / 8; //Take the actual pixel number and divide it by 8 to get the Byte location in the Char array
int remainder = pixel % 8; //Take the modulus of the pixel number by 8 to get the bit inside of the byte location
unsigned char bufferByte = pgm_read_byte(&bmp[byteNum]); //Use the byte location to save the byte into a Buffer to read the bits
int activePixel = bitRead(bufferByte, 7 - remainder); //We need the bits from left to right so the remained is subtracted by 7 to get the proper bit
return activePixel; //Return the 1 or 0 in the bit location
}
const unsigned char bmp [] PROGMEM = {elements in hex}
the error message
"redefinition of 'const unsigned char bmp []'"
