9. Case 06: An Obstacle-avoidance Car

9.1. Purpose

---

Make an obstacle-avoidance car with NezhaA Inventor’s Kit.

9.2. Purchse

---

NezhaA Inventor’s Kit

9.3. Materials Required

---

9.4. Assembly Steps

---

9.5. Hardware Connections

---

Connect two motors to M1, M2 port and the ultrasonic sound sensor to J1 port on Nezha-A master box.

9.6. Programming

---

9.6.1. Prepare the programming

Steps for preparation please refer to: Arduino 3 in 1 Breakout Board

Import the libraries and the subsidiary libraries of Nezha-A master box and then import the libraries of the ultrasonic sound sensor: PlanetXUltrasonic-main.zip Download and import the self-defined library connections for Nezha-A master box: RJPins-main.zip

9.6.2. Sample Projects:

// Language ArduinoC
#include <PlanetXUltrasonic.h>
#include <NezhaA.h>
#include <RJPins.h>

PlanetXUltrasonic ultrasonicJ1(J1);    //Create an instance of PlanetXUltrasonic category
NezhaA nezhaa;    //Create an instance of NezhaA category
int distance;    //Create a variable of int distance

void setup() {
  nezhaa.begin();    //Initiliaze the buzzer, motor, servo and light
}

void loop() {
  distance = (ultrasonicJ1.getDistance());    //Set the detected value from ultrasonic sound sensor as the variable distance 
  if (distance > 3 && distance < 20) {    //Judge if the variable is over 3 and below 20
    nezhaa.setMotorSpeed(M1, 15);    // Set the speed of the motor connecting to M1 at 15%
    nezhaa.setMotorSpeed(M2, -15);    //Set the speed of the motor connecting to M2 at -15%
    delay((1) * 1000);    //Pause 1000ms
  } else {
    nezhaa.setMotorSpeed(M1, 20);
    nezhaa.setMotorSpeed(M2, 20);
  }
}

9.6.3. Result

After powering on, the car moves forward and it turns autamatically if it detects any obstacles.