Lamp.ino

#include <NewPing.h>
#define ECHO_PIN DD5
#define TRIG_PIN DD4
#define RELAY_PIN LED_BUILTIN
#define SENSOR_MIN_DISTANCE 10  // cm
#define DEBUG

class UltrasonicSensor {
   private:
    uint8_t trig_pin;
    uint8_t echo_pin;
    unsigned long _duration;

   public:
    UltrasonicSensor(uint8_t trig_pin, uint8_t echo_pin) {
        this->trig_pin = trig_pin;
        this->echo_pin = echo_pin;
        pinMode(trig_pin, OUTPUT);
        pinMode(echo_pin, INPUT);
        digitalWrite(trig_pin, LOW);
    }

    static double durationToCentimeters(unsigned long duration) {
        return duration * 0.017;
    }

    double getCentimetersDistance() {
        digitalWrite(TRIG_PIN, LOW);
        delayMicroseconds(2);
        digitalWrite(TRIG_PIN, HIGH);
        delayMicroseconds(10);
        digitalWrite(TRIG_PIN, LOW);
        // Microseconds
        _duration = pulseIn(ECHO_PIN, HIGH);
        // Centimeters
        return _duration * 0.017;
    }

    unsigned long lastDuration() const { return _duration; }
};

void setup() {
    pinMode(RELAY_PIN, OUTPUT);
#ifdef DEBUG
    Serial.begin(9600);
#endif
}

void loop() {
    static NewPing sonar(TRIG_PIN, ECHO_PIN, SENSOR_MIN_DISTANCE + 30);
    static unsigned long previous_turn = millis();
    unsigned long distance;
    if (millis() - previous_turn > 1000 &&
        (distance = sonar.convert_cm(sonar.ping_median())) <
            SENSOR_MIN_DISTANCE &&
        distance > 0) {
        digitalWrite(RELAY_PIN, digitalRead(RELAY_PIN) == HIGH ? LOW : HIGH);
        previous_turn = millis();
#ifdef DEBUG
        Serial.println("-------------------\nDistance = " + String(distance) +
                       " см");
#endif
    }
#ifdef DEBUG
    Serial.println("Distance = " + String(distance) + " см");
#endif
}