Smart Stop 1.0

Note

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Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

Name	Includes Arduino board	PURCHASE LINK
Elite Explorer Kit	Arduino Uno R4 WiFi	BUY
3 in 1 Ultimate Starter Kit	Arduino Uno R4 Minima	BUY

Course Introduction

In this lesson, you’ll learn how to use an L9110 Motor Driver Module, an Ultrasonic Sensor Module, and a TT motor with the Arduino UNO R3 to create a Smart Stop 1.0 system.

As the obstacle gets closer to the Ultrasonic Sensor Module, the TT motor gradually slows down until it comes to a stop.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino UNO R3	1	BUY
2	USB Cable	1
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	L9110 Motor Driver Module	1
6	Ultrasonic Sensor Module	1	BUY
7	TT Motor	1

Wiring

Common Connections:

Ultrasonic Sensor Module
- Trig: Connect to 4 on the Arduino.
- Echo: Connect to 3 on the Arduino.
- GND: Connect to breadboard’s negative power bus.
- VCC: Connect to breadboard’s red power bus.
TT Motor
- Connect to MOTOR B on the L9110 Motor Driver Module.
L9110 Motor Driver Module
- GND: Connect to breadboard’s negative power bus.
- VCC: Connect to breadboard’s red power bus.
- B-1B: Connect to 9 on the Arduino.
- B-1A: Connect to 10 on the Arduino.

Writing the Code

Note

You can copy this code into Arduino IDE.
Don’t forget to select the board(Arduino UNO R3) and the correct port before clicking the Upload button.

// Define pins for ultrasonic sensor and motor
const int echoPin = 3;
const int trigPin = 4;
const int motorB_1A = 9;
const int motorB_2A = 10;

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud rate
  pinMode(echoPin, INPUT); // Set echo pin as input for receiving signals
  pinMode(trigPin, OUTPUT); // Set trig pin as output for sending signals
  pinMode(motorB_1A, OUTPUT); // Set motor control pin 1 as output
  pinMode(motorB_2A, OUTPUT); // Set motor control pin 2 as output
}

void loop() {
  float distance = readSensorData(); // Get distance from ultrasonic sensor using the new function name
  Serial.print("Distance: "); // Print distance for debugging
  Serial.print(distance);
  Serial.println(" cm");
  controlMotor(distance); // Control motor speed based on distance
  delay(100); // Delay to reduce sensor noise impact
}

float readSensorData() {
  digitalWrite(trigPin, LOW); // Ensure clean pulse
  delayMicroseconds(2); // Wait for 2 microseconds
  digitalWrite(trigPin, HIGH); // Send high pulse for 10 microseconds
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW); // Reset trig pin to low
  unsigned long duration = pulseIn(echoPin, HIGH); // Measure echo pulse width
  float distance = duration / 58.00; // Calculate distance in cm, simplifying the calculation
  return distance;
}

void controlMotor(float distance) {
  if (distance < 5) {
    analogWrite(motorB_1A, 0); // Stop motor if distance is less than 5 cm
    analogWrite(motorB_2A, 0);
  } else if (distance < 8) {
    analogWrite(motorB_1A, 85); // Set speed to 85 if distance is less than 8 cm
    analogWrite(motorB_2A, 0);
  } else if (distance < 11) {
    analogWrite(motorB_1A, 170); // Set speed to 170 if distance is less than 11 cm
    analogWrite(motorB_2A, 0);
  } else if (distance > 14) {
    analogWrite(motorB_1A, 255); // Set speed to maximum if distance is more than 14 cm
    analogWrite(motorB_2A, 0);
  }
}