The program reads binary 0's & 1s stored in a word array in row/column fashion & then controls the motors accordingly. You can change what it prints by changing the data in the "image" array. It's pretty basic & shouldn't be too hard to understand or change to fit your wants better.
I included the schematic I followed for wiring the H-Bridge Motor Drivers (SN754410NE). I apologize for not having a complete schematic I have not found an easy way to make them. I used an LM317 5V regulator for each H-bridge, but honestly since I used a computer power supply to give me 5V you shouldn't even need the LM317's. You could just take the 5v from the power supply & wire it to each H-Bridge. In my case I built the control board before choosing a power supply.
Part List Quantity Cost Total
H-Bridge Motor Driver 1A (SN754410NE) 3 $2.35 $29.25
Voltage Regulator (LM317) 3 ~$1.95
10uF/25V Capacitor 3 ~$0.45
Used CD-ROM 3 ~$5.00
Arduino Duemilanove/UNO (This indestructible assumes that you already have one) ;)
If you don't already have an Arduino the total cost will be closer to $60.00.
In case you don't want to download the zip file, the code is below:
//Beginning
#include <Stepper.h>
// change this to the number of steps on your motor
#define STEPS 200
// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
Stepper stepperX(STEPS, 6, 7, 8, 9); //x (top) platform
Stepper stepperY(STEPS, 2, 3, 4, 5); //y (bottom) platform
Stepper stepperZ(STEPS, 10, 11, 12, 13); //z pen
int x_inc = 0;
int y_inc = 0;
int z_pos = 0;
word image[16] = {
0b0000001110000000,
0b0010011111000100,
0b0010001110000100,
0b0010000100000100,
0b0011111111111100,
0b0000011111000000,
0b0000011111000000,
0b0000001110000000,
0b0000011111000000,
0b0000011111000000,
0b0000110001100000,
0b0001100000110000,
0b0001100000110000,
0b0011100000111000,
0b0011100000111000,
0b1111111111111111
};
void setup()
{
// set the speed of the motors to 60 RPMs
stepperX.setSpeed(60); //bottom (60rpm)
stepperY.setSpeed(60); //top (60rpm)
stepperZ.setSpeed(60); //Pen (60rpm);
delay(2000);
}
void loop()
{
for(int row = 0; row < 16; row++) {
penUp();
stepperX.step(-x_inc);
x_inc = 0;
for(int column = 0; column < 16; column++){
boolean pixel = bitRead(image[row],column);
if(pixel == 1){
penDown();
//move X-Axis forward 5 steps for each bit in the array
stepperX.step(10);
x_inc = x_inc + 10;
delay(15);
}
else{
penUp();
//move X-Axis forward 5 steps for each bit in the array
stepperX.step(10);
x_inc = x_inc + 10;
delay(15);
}
}
penUp();
//Position Y-Axis for next row
stepperY.step(10);
y_inc = y_inc + 10;
delay(15);
}
penUp();
//Return X/Y-Axis back to home position
stepperX.step(-x_inc);
stepperY.step(-y_inc);
//Endless Loop
while(1){
}
}
void penDown()
{
//if the pen is raised
if (z_pos == 0){
//move the pen to the paper
stepperZ.step(83);
delay(15);
z_pos = 83;
}
}
void penUp()
{
//if the pen against the paper
if(z_pos == 83){
//move pen away from paper
stepperZ.step(-83);
delay(15);
z_pos = 0;
}
}
//END
//Beginning
#include <Stepper.h>
// change this to the number of steps on your motor
#define STEPS 200
// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to
Stepper stepperX(STEPS, 6, 7, 8, 9); //x (top) platform
Stepper stepperY(STEPS, 2, 3, 4, 5); //y (bottom) platform
Stepper stepperZ(STEPS, 10, 11, 12, 13); //z pen
int x_inc = 0;
int y_inc = 0;
int z_pos = 0;
word image[16] = {
0b0000001110000000,
0b0010011111000100,
0b0010001110000100,
0b0010000100000100,
0b0011111111111100,
0b0000011111000000,
0b0000011111000000,
0b0000001110000000,
0b0000011111000000,
0b0000011111000000,
0b0000110001100000,
0b0001100000110000,
0b0001100000110000,
0b0011100000111000,
0b0011100000111000,
0b1111111111111111
};
void setup()
{
// set the speed of the motors to 60 RPMs
stepperX.setSpeed(60); //bottom (60rpm)
stepperY.setSpeed(60); //top (60rpm)
stepperZ.setSpeed(60); //Pen (60rpm);
delay(2000);
}
void loop()
{
for(int row = 0; row < 16; row++) {
penUp();
stepperX.step(-x_inc);
x_inc = 0;
for(int column = 0; column < 16; column++){
boolean pixel = bitRead(image[row],column);
if(pixel == 1){
penDown();
//move X-Axis forward 5 steps for each bit in the array
stepperX.step(10);
x_inc = x_inc + 10;
delay(15);
}
else{
penUp();
//move X-Axis forward 5 steps for each bit in the array
stepperX.step(10);
x_inc = x_inc + 10;
delay(15);
}
}
penUp();
//Position Y-Axis for next row
stepperY.step(10);
y_inc = y_inc + 10;
delay(15);
}
penUp();
//Return X/Y-Axis back to home position
stepperX.step(-x_inc);
stepperY.step(-y_inc);
//Endless Loop
while(1){
}
}
void penDown()
{
//if the pen is raised
if (z_pos == 0){
//move the pen to the paper
stepperZ.step(83);
delay(15);
z_pos = 83;
}
}
void penUp()
{
//if the pen against the paper
if(z_pos == 83){
//move pen away from paper
stepperZ.step(-83);
delay(15);
z_pos = 0;
}
}
//END
Source:http://www.instructables.com/id/Cheap-Arduino-Controlled-3-Axis-Pen-Plotter/
