Uno - error during uploading with library

Question

I'm writing the code in VS Code on IO Platform. Yesterday i finished my code and uploaded it to the Arduino Uno. It works fine. Next day i launched the VS Code and i changed the code a bit, then i uploaded it and i got the error.

Error:

Tone.cpp.o (symbol from plugin): In function `timer0_pin_port':
(.text+0x0): multiple definition of `__vector_7'
NewPing.cpp.o (symbol from plugin):(.text+0x0): first defined here
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\uno\firmware.elf] Error 1

I am using the libary NewPing.h. The code should does this: If is distance more than 20cm, the the buzz makes the sound and turns on the red led. If distance is less than 20cm, the blue led turns on

The code:

#include <Arduino.h>  //It has to be there, because the arduino ide in VS Code will not work.

#include <NewPing.h>

#define echo_pin 3
#define trig_pin 4
#define max_range 450

#define red_led_pin 7
#define blue_led_pin 9
#define buzz_pin 10

int distance = 0;

NewPing sonar(trig_pin, echo_pin, max_range);






void setup(){
  Serial.begin(9600);
  pinMode(red_led_pin, OUTPUT);
  pinMode(blue_led_pin, OUTPUT);

  pinMode(buzz_pin, OUTPUT);
}



void loop() {

  distance = sonar.ping_cm();
  delay(50);

  if (distance > 0) {
          distance = 0;

    for (int i=0; i<5; i++) {
      distance += sonar.ping_cm();
      delay(50);
    }
    distance /= 4;

    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println("cm");

    if (distance > 20) {

      digitalWrite(blue_led_pin, LOW);
      digitalWrite(red_led_pin, HIGH);
      tone(buzz_pin, 1500);
      tone(buzz_pin, 800);
    }

    else {

      digitalWrite(red_led_pin, LOW);
      digitalWrite(blue_led_pin, HIGH);
    }
  }
}

I don't undersand, what has changed. I tried to import again the libary https://www.arduino.cc/en/guide/libraries by importing the *.zip file, also installing in IDE.

Answer 1

You have a conflict of interrupts. Both the internal tone() command and the NewPing.h use Timer 2 by default, which makes them mutually exclusive.

However you can change NewPing to not use a timer by editing the src/NewPing.h file and setting TIMER_ENABLED to be false:

    #define TIMER_ENABLED true      // Set to "false" to disable the timer ISR (if getting "__vector_7" compile errors set this to false). Default=true