105 lines
3.5 KiB
C++
105 lines
3.5 KiB
C++
#include <ESP32Servo.h>
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Servo myservo; // create servo object to control a servo
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int servo_angle = 0; // variable to store the servo position
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#define SERVOPIN 16 // Recommended PWM GPIO pins on the ESP32 include 2,4,12-19,21-23,25-27,32-33
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#define SERVO_LEFT 45
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#define SERVO_RIGHT 135
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#define SERVO_FORWARD 90
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#define US_TRIG 12
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#define US_ECHO 14
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#define US_STOP_DISTANCE 10
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long distance_forward_cm,distance_left_cm,distance_right_cm;
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void setup() {
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//Serial port
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Serial.begin(115200);
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//Ultra sonic pins
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pinMode(US_TRIG, OUTPUT);
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pinMode(US_ECHO, INPUT);
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//servo init
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myservo.attach(SERVOPIN); // attaches the servo on pin 18 to the servo object
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// using default min/max of 1000us and 2000us
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// different servos may require different min/max settings
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// for an accurate 0 to 180 sweep
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delay(1000);
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myservo.write(SERVO_FORWARD); // start looking forward
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delay(2000);
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myservo.write(SERVO_LEFT); // start looking forward
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delay(2000);
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myservo.write(SERVO_FORWARD); // start looking forward
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delay(2000);
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myservo.write(SERVO_RIGHT); // start looking forward
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delay(2000);
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myservo.write(SERVO_FORWARD); // start looking forward
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}
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void loop() {
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distance_forward_cm = measure_distance_cm(); // measure the distance in front of us
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if(distance_forward_cm<US_STOP_DISTANCE){
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//there is something in front of us
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myservo.write(SERVO_LEFT); // look the left and meaasure distance
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delay(1000); // wait 1s
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distance_left_cm = measure_distance_cm(); // measure the distance in left of us
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delay(1000); // wait 1s
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myservo.write(SERVO_RIGHT); // look the left and meaasure distance
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delay(1000); // wait 1s
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distance_right_cm = measure_distance_cm(); // measure the distance in left of us
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delay(1000); // wait 1s
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if(distance_left_cm > distance_right_cm){
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// goto to the left
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for(int pos = SERVO_FORWARD;pos>SERVO_LEFT;pos--){
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myservo.write(pos);
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delay(15);
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}
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}
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else{
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// goto to the right
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for(int pos = SERVO_FORWARD;pos<SERVO_RIGHT;pos++){
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myservo.write(pos);
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delay(15);
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}
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}
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delay(1000);
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myservo.write(SERVO_FORWARD);
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delay(1000);
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}
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delay(250);//ms
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}
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long measure_distance_cm(){
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long distance_cm,echo_duration;
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// start measurment by a short high pulse of 10 microseconds length at the trig pin ...
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digitalWrite(US_TRIG,LOW);
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delayMicroseconds(2);
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digitalWrite(US_TRIG,HIGH);
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delayMicroseconds(10);
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digitalWrite(US_TRIG,LOW);
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// measure the duration in microseconds of the echo pin HIGH - this is the time the echo needs to be back at the sensor
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pinMode(US_ECHO,INPUT);
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echo_duration = pulseIn(US_ECHO,HIGH);
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// convert into cm ... 344m/sec is the speed of noise - thus 34400cm/sec ... or 34,400cm/milisec ... or 0,0344cm/microsec
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// the echo has to go the distance twice - forth and back - so the duration has to be the half of the measured one
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// distance_cm = echo_duration/2 * 0,0344 or distance_cm = echo_duration/2 / 29,1
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distance_cm = (echo_duration/2) / 29.1;
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//print this result at the screen
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Serial.print("Distance in cm: ");
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Serial.println(distance_cm);
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return(distance_cm);
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}
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