Index
Introduction
The ESP32-C3 SMARS Robot is a compact, 3D-printed robot platform.
It is powered by the ESP32-C3 Super Mini with Expansion Board.
An ultrasonic sonar sensor helps the robot detect and avoid obstacles.
Dual N20 3V metal gear motors are driven by a Mini Dual DC Motor Driver for smooth motion.
A push button with a 10K resistor provides manual control and reset functionality.
Required Components
- ESP32-C3 Super mini with Expension Board
- Sonar Sensor
- Push Button with 10K Ohm Resistor
- Mini Dual DC Motor Driver
- N20 DC 3V Metal Gear Motor
- Zero PCB
3D Parts
Circuit Diagram
- HC-SR04
- VCC β ESP32-C3 5V
- GND β ESP32-C3 GND
- TRIG β ESP32-C3 10
- ECHO β ESP32-C3 5
- Motor Driver
- IN1 β ESP32-C3 6 (motor A control pin 1)
- IN2 β ESP32-C3 7 (motor A control pin 2)
- IN3 β ESP32-C3 8 (motor B control pin 1)
- IN4 β ESP32-C3 9 (motor B control pin 2)
- Motors
- Motor A outputs β Driver Motor A output pins
- Motor B outputs β Driver Motor B output pins
- Push Button
- One Side of Push Button β ESP32-C3 5V with 10k Ohm Resistor (For pullup)
- One Side of Push Buttonβ ESP32-C3 GND
- One Side of Push Button β ESP32-C3 4
Code
#define TRIG_PIN 10
#define ECHO_PIN 5
#define IN1 6
#define IN2 7
#define IN3 8
#define IN4 9
long duration;
int distance;
void setup() {
Serial.begin(115200);
pinMode(TRIG_PIN, OUTPUT);
pinMode(ECHO_PIN, INPUT);
pinMode(IN1, OUTPUT);
pinMode(IN2, OUTPUT);
pinMode(IN3, OUTPUT);
pinMode(IN4, OUTPUT);
}
void loop() {
// Measure distance
digitalWrite(TRIG_PIN, LOW);
delayMicroseconds(2);
digitalWrite(TRIG_PIN, HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN, LOW);
duration = pulseIn(ECHO_PIN, HIGH);
distance = duration * 0.034 / 2;
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");
if (distance < 15) {
// Obstacle: go backward
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
delay(500);
// Turn right
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
delay(500);
} else {
// Move forward
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, LOW);
}
delay(100);
}
