{"id":97,"date":"2025-11-02T14:42:26","date_gmt":"2025-11-02T19:42:26","guid":{"rendered":"https:\/\/wp.stgeorges.bc.ca\/deans\/?p=97"},"modified":"2025-11-04T16:48:25","modified_gmt":"2025-11-04T21:48:25","slug":"robotics-project","status":"publish","type":"post","link":"https:\/\/wp.stgeorges.bc.ca\/deans\/2025\/11\/02\/robotics-project\/","title":{"rendered":"ROBOTICS PROJECT"},"content":{"rendered":"\n

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INTRO<\/h2>\n\n\n\n

For this robotics assignment, I designed and built a motion-activated automatic door using Arduino Uno, PIR motion sensor, and servo motor. The goal of the project was to demonstrate core Arduino skills such as circuit building and coding, while creating a functional robotic device that reacts to human movement. I created and tested the circuit virtually using Tinkercad before attempting real life assembly.<\/p>\n\n\n\n

OVERVIEW<\/h2>\n\n\n\n

The project simulates an automatic door that opens when a person approaches. When the PIR sensor detects motion, it sends a signal to the Arduino, which then activates the servo motor to open the door. After a three-second delay, the servo returns to its original position, closing the door.<\/p>\n\n\n\n

CODE<\/strong><\/h2>\n\n\n\n
#include <Servo.h>\n\nServo doorServo;     \nint pirPin = 2;        \nint pirState = LOW;   \n\nvoid setup() {\n  doorServo.attach(9);   \n  pinMode(pirPin, INPUT); \n  doorServo.write(0);   \n}\n\nvoid loop() {\n  int motionDetected = digitalRead(pirPin);\n\n  if (motionDetected == HIGH && pirState == LOW) {\n    doorServo.write(90); \n    pirState = HIGH;\n    delay(3000);         \n    doorServo.write(0); \n    pirState = LOW;\n  }\n\n  delay(200); \n}\n<\/code><\/pre>\n\n\n\n
CODE BREAKDOWN<\/p>\n\n\n\n
#include <Servo.h>\n\nServo doorServo;       \nint pirPin = 2;        \nint pirState = LOW;    \n<\/code><\/pre>\n\n\n\n
This section includes the servo library, which allows the Arduino to control servo motors. It creates a servo object called doorServo<\/strong> for controlling the door. pirPin<\/strong> defines    which pin the PIR sensor is connected to, and pirState<\/strong> keeps track of whether motion has been detected, helping to prevent the door from repeatedly opening when motion is continuous.<\/p>\n\n\n\n
void setup() {\n  doorServo.attach(9);   \n  pinMode(pirPin, INPUT);\n  doorServo.write(0);    \n}<\/code><\/pre>\n\n\n\n
In the setup()<\/strong> function, the servo is attached to pin 9, which will control the door. The PIR sensor pin is set as an input so the Arduino can read motion detection signals. Finally, doorServo.write(0) <\/strong>ensures the door starts in the closed position when the program begins.<\/p>\n\n\n\n
void loop() {\n  int motionDetected = digitalRead(pirPin);\n\n  if (motionDetected == HIGH && pirState == LOW) {\n    doorServo.write(90);  \n    pirState = HIGH;\n    delay(3000);          \n    doorServo.write(0);   \n    pirState = LOW;\n  }\n\n  delay(200); \n}<\/code><\/pre>\n\n\n\n
The loop()<\/strong> function constantly reads the PIR sensor with digitalRead(pirPin)<\/strong>. If motion is detected (motionDetected == HIGH<\/strong>) and the door is not already open (pirState == LOW<\/strong>), the servo rotates to 90\u00b0 to open the door. The program waits for 3 seconds before closing the door by returning the servo to 0\u00b0. The pirState<\/strong> variable prevents repeated triggering while motion continues, and the delay(200)<\/strong> at the end prevents jitter from rapid sensor signals.<\/p>\n\n\n\n
BILL OF MATERIALS (BOM)<\/h2>\n\n\n\n
Component<\/th>Quantity<\/th>Function<\/th><\/tr><\/thead>
Arduino Uno<\/td>1<\/td>Microcontroller board<\/td><\/tr>
PIR Motion Sensor<\/td>1<\/td>Detects motion (input)<\/td><\/tr>
Servo Motor <\/td>1<\/td>Controls door movement (output)<\/td><\/tr>
Jumper Wires<\/td>6<\/td>Electrical connections<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
VIRTUAL PROTOTYPE<\/h2>\n\n\n\n
I used Tinkercad to build the first version of the circuit to ensure both the wiring and code worked properly before physical assembly.
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The circuit works as follows:<\/p>\n\n\n\n