A simple library that turns an Arduino and a couple of motors into a 2D plotter. The microcontroller uses two stepper motors to set the horizontal position of the end effector and uses a servo to move it closer and further away from the surface.

• main class representing the plotter

• stepper motor controlling movement along X axis

• stepper motor controlling movement along Y axis

• servo for lifting of the end effector

• EEPROM address for storing X position of the end effector
• default value: 0

• EEPROM address for storing Y position of the end effector
• default value: 2

• size of the character in stepper motor moves (same for both axes)

• actual line where the end effector works (starts from 0)

• actual character (position in line) where the end effector works (starts from 0)

• number of lines on the page

• number of chars in the line

• saves current EE position (in stepper motor moves from start of the page) to the EEPROM

• loads saved EE position from the EEPROM (loaded values are divided by the size of the char)

• moves EE to the surface

• lifts EE from the surface

• moves EE for one stepper motor move upwards (along the Y axis)

• moves EE for one stepper motor move upwards to the right

• moves EE for one stepper motor move to the right (along the X axis)

• moves EE for one stepper motor move downwards to the right

• moves EE for one stepper motor move downwards (along the Y axis)

• moves EE for one stepper motor move downwards to the left

• moves EE for one stepper motor move to the left (along the X axis)

• moves EE for one stepper motor move upwards to the left

• writes letter A

• writes letter B

• writes letter C

• writes letter D

• writes letter E

• writes letter F

• writes letter G

• writes letter H

• writes letter I

• writes letter J

• writes letter K

• writes letter L

• writes letter M

• writes letter N

• writes letter O

• writes letter P

• writes letter Q

• writes letter R

• writes letter S

• writes letter T

• writes letter U

• writes letter V

• writes letter W

• writes letter X

• writes letter Y

• writes letter Z

• writes space sign

• writes dot sign

• writes dash sign

• writes slash sign

• writes plus sign

• initializes attributes sets maximal number of lines and chars (depends on char size)
• arguments:
  • StepperMotor* motorX - see private attributes
  • StepperMotor* motorY - see private attributes
  • Servo* servo - see private attributes
  • uint16_t charSize - see private attributes
  • bool loadPositionOnStart - indicates, if the position of the EE should be loaded from EEPROM

• changes the size of the char
• arguments:
  • uint16_t newSize - new value of the charSize

• moves EE to the start of the page (line 0, char 0)

• moves EE to the start of the next line

• draws test picture

• Writes given string. If the number of characters exceeds the line length, EE is moved to the next line. If the entire page is used, the remaining characters are discarded.
• arguments:
  • String* text - string to be written

The library was tested with Arduino Nano, two 28BYJ-48 stepper motors and SG90 servo.

• EEPROM
• Servo
• Stepper Motor

Contributions are welcome!

The library is licensed under the MIT license.