2.2COMPONENTS

The circuit ofaDIYdrawingrobotusingArduinoUnoinvolvesconnectingvariouscomponents, such as stepper motors, sensors, and power supply, to the Arduino Uno board. Here are some detailsofthecircuitcomponentsandtheirconnections:

1. ARDUINOUNOBOARD

Arduino Uno is a microcontroller board based ontheATmega328Pmicrocontrollerchip. The Arduino Uno board is the main controlleroftheroboticsystem,anditisresponsible for sending signals to the various components. The board has several input and output pins, including analog and digital pins, which are used to connect to the other components. The board is powered by a voltage source, such as a USBcableorapower supply, and it communicates with a computer or other devices using a serial communicationprotocol.

TechnicalSpecifications:

1. Microcontroller:ATmega328P

2. OperatingVoltage:5V

3. InputVoltage(recommended):7-12V

4. InputVoltage(limits):6-20V

5. DigitalI/OPins:14(ofwhich6providePWMoutput)

6. PWMDigitalI/OPins:6

7. AnalogInputPins:6

8. DCCurrentperI/OPin:20mA

9. DCCurrentfor3.3VPin:50mA

10.FlashMemory:32KB(ATmega328P)ofwhich0.5KBusedbybootloader

11. SRAM:2KB(ATmega328P)

12.EEPROM:1KB(ATmega328P)

13.ClockSpeed:16MHz

2. ARDUINOSENSORSHIELD

An Arduino sensor shield is a board that isdesignedtobemountedontopofanArduino microcontroller board to provide additional sensor capabilities. The shield typically contains a variety of sensors such as temperature, humidity, light, sound, motion, and many others, as well as additional circuitry to interface the sensors with the Arduino board.

The shield allows the Arduino to read data from the sensors and use that data to control other devices or perform various actions. Arduino sensor shields are available in a wide variety of configurations, with different sensors and features depending on the specific needsoftheproject.

3. MOTORS(Stepper28BYJ-48andServo)

The robot requires at least two stepper motors and one servo motor to control the movement of the pen. These motors will need to be connected to motor drivers that can convert the signals from the Arduino into appropriatepoweranddirectionsignalsforthe motors.

Stepper motors are used to move the robot's arms and pen to draw on a surface. The 28BYJ-48 is a small 5V stepper motor commonly used in hobbyist and DIY electronics projects. It is a 4-phase, 8-step motor that is capable of very precise control using an appropriatecontroller.Herearesomekeyspecifications:

Voltage:5VDC

Current:250mA

Resistance:20ohmsperwinding

Stepangle:5.625degrees/64stepsperrevolution

Holdingtorque:34.3mN.m(approx.48oz.in)

The motor can be controlled using a variety of stepper motor driver boards, such as the popular ULN2003 driver board, which provides four Darlington transistor pairs to drive the motor coils. The motor can be wired in various configurations depending on the driverboardusedandthedesireddirectionandspeedofrotation.

Featuresofmotordriver:

1. Minimum-Maximumoperatingvoltage:8-35V

2. Continuouscurrentperphase:1Amp

3. Maximumcurrentperphase:2Amp

4. Minimum-Maximumlogicvoltage:3-5.5V

5. Microstepresolutions:Full,1/2,1/4,1/8,and1/16

6. Reversevoltageprotection?No

The 28BYJ-48 is often used in small robotics projects, such as for controlling the movementofsmallrobotarmsorforprecisecontrolofsmallCNCmachines.

Servo motors are used to move the pen up and down to allow for different drawing heights. A servo motor is a type of rotary actuatorthatiscommonlyusedinroboticsand other applications where precise control of position and velocity is required. Itworksby rotatinganoutputshafttoaspecificanglebasedonacontrolsignal.

Sometechnicalspecificationsofatypicalservomotorinclude:

Torque: This is the rotational force that the servo motor can produce. It is usually measuredinunitssuchasNewton-meters(Nm)orounce-inches(oz-in).

Speed:Thisisthemaximumrotationalspeedoftheservomotor.Itisusuallymeasuredin unitssuchasrevolutionsperminute(RPM)ordegreespersecond(°/s).

Operating Voltage: This is the voltage range over which the servomotorcanoperate.It isusuallymeasuredinvolts(V).

Control Signal: This is the type of signal used to control the servo motor The most common type is a pulse-widthmodulation(PWM)signal,whichisusedtosetthedesired positionoftheoutputshaft.

It's important to choose a servo motor with specifications that matchtherequirementsof your project. Some other factors to consider include the durability and reliability of the motor,aswellastheavailabilityofcompatiblecontrolsystemsandaccessories.

4. MICROSDCARD

A micro SD card can be usedinaDIYdrawingrobotusingArduinotostoreandretrieve drawings or other data related to the robot. Here are some ways a micro SD card canbe usedinthistypeofproject:

1. Storing drawing instructions: One way to use amicroSDcardistostoredrawing instructions or commands that are sent to the Arduino microcontroller. This allows for more complex drawings to be created without overloading the microcontroller's memory. The microcontroller can read the drawing instructions fromtheSDcardandexecutethemtocreatethedrawing.

2. Saving and retrieving drawings: Another use for the micro SD card is to store completed drawings, so they can be retrieved and displayed later. This can be usefulforcreatingaportfolioofdrawingsorsharingdrawingswithothers.

3. Calibration data: The micro SD card can also be usedtostorecalibrationdatafor the robot's motors and sensors. This data can be used to ensure accurate movementsandprecisedrawingplacement.

To use a micro SD card in a DIY drawing robot using Arduino, an SD card module can be connected to the Arduino board. The module provides asimplewaytoreadandwrite data to the SD card. The Arduino code can be programmed to read and write datatothe SD card using the appropriate libraries and functions. With the SD card module and appropriate programming, the DIY drawing robot can store and retrieve drawings, instructions,andcalibrationdatafromthemicroSDcard.

5. PENHOLDER,BELTSANDPULLEYS

A pen holder is used toholdthepenormarkerthatisusedfordrawing.Beltsandpulleys areusedtotransmitthemotionofthesteppermotorstotherobot'sarmsandpen.

6. POWERSUPPLY

An additional 9V power supply is required to power the motors and other electronic componentsoftherobot.