We built a 2d xy plotter machine which can efficiently print letters and words and control it through bluetooth using an android app. There are two stepper motors-one which controlled the movement along y direction which moved the whole central limb(having a metal plate ,servo motor and pen and the second stepper motor) .The second stepper controlled the movement along x direction by moving the pen holding plate.
Components Used
- 2 stepper motors
- Servo motor
- 2 L298N motor drivers
- Arduino uno
- Bluetooth module HC05,
- Gears and belts
- Metal rods
- Some basic hardware made from wood
Solidworks Base model of our Design
Stepper Motors – L298N Motor Driver
Stepper motors are DC motors that move in discrete steps. They have multiple coils that are organized in groups called “phases”. By energizing each phase in sequence, the motor will rotate, one step at a time. With a computer controlled stepping you can achieve very precise positioning and/or speed control.
WORKING– stepper motors consists of coils and depending upon which coil is energised it rotates . It consists of stator (electromagnet) and rotor(permanent magnet) and depending upon which coil is energised the rotor rotates in steps.
WHY ARE WE USING STEPPER INSTEAD OF simple motors?
As the stepper motors rotates in steps so we can precisely control its movement which we require to print letters and depending upon step angle which is 1.8 deg in nema 23 stepper motors which we are using we can measure the distance till which it will run and can have precise stepping to print letters which is not possible using simple dc motors.
Software – Arduino Programming
At first we tried to run the stepper motors using a normal motor driver L293D but we were not able to run the motors as its output current was only 1 amp and the stepper motors which we were using NEMA 23 STEPPER MOTOR whose current specification was above 2 amp so we decided to use L298N motor driver. It consists of two output ports, one each for the two coils in the stepper motors and four input pins connected to the Arduino Uno pins based on which the motor runs. And there is one power port consisting of 12V, Ground and 5V to power the motors.
By controlling the stepper motors in x and y direction and controlling the servo motor for pen up-down mechanism we can write different letters
By using the built-in libraries for stepper motors and servos, we can create (X and Y) stepper motor objects and a (Z) servo motor object. We utilize the attach(pinNumber) function to connect the control pin of the servo motor to a specific pin on the Arduino board. The write(position) function allows us to turn the servo motor to a specified angle as defined in the parameters; both of these functions are part of the servo library.
To control the stepper motors, we can use the setSpeed(10) function, where the speed is set to 10 RPM. Additionally, the step(100) function commands the stepper motor to rotate 100 steps. These functions are included in the stepper library.
By providing instructions to the X and Y stepper motors using the step() function, we can write code to print different letters.
Arduino Code to write the letter ‘E’
Arduino Code – Serial Communication
After writing the codes for different letters we decided to write words which we will send to the arduino via bluetooth module hc05 through an android app created by us using mit app inventer (click on mit app inventer for more information) . We did this by using serial communication in arduino
Team
- SHREYANSH NANAWATI (MECHANICAL)
- DHEERAJ BOGHISHETTY (MECHANICAL)
- VEDANT PANSE (MECHANICAL)
- SRINIVAS (MECHANICAL)
Mentors
- PRANAY POURKAR
- TUSHAR UMREDKAR