Dear Arduino Community,
First of all I am sorry in advance to post this message on this topicon but for some reasons I cannot post any topic on the Audio section of the forum…
I have started an MP3 project with a DFPlayer Mini linked to a ultrasonic sensor.
So far everything works fine but in my "void loop", I tried to set up a volume fade in with a for loop into myDFPlayer.volume() , but unfortunately nothing works correctly (nothing happends), this is why I had to make this messy synthax changing the volume bite by bite…
Does anyone ever struggled with that probleme, there might be something wrong in my code 
?
All the best,
B.
#include "SoftwareSerial.h"
#include "DFRobotDFPlayerMini.h"
#include <PCM.h>
SoftwareSerial mySoftwareSerial(10, 11); // RX, TX
DFRobotDFPlayerMini myDFPlayer;
const int trigPin = 13;
const int echoPin = 12;
// defining variables for sensor
long duration;
int distance;
// defining buttons for mp3 player
int buttonNext = 2;
int buttonPause = 3;
int buttonPrevious = 4;
boolean isPlaying = false;
void setup() {
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
pinMode(buttonPause, INPUT);
digitalWrite(buttonPause, HIGH);
pinMode(buttonNext, INPUT);
digitalWrite(buttonNext, HIGH);
pinMode(buttonPrevious, INPUT);
digitalWrite(buttonPrevious, HIGH);
mySoftwareSerial.begin(9600);
Serial.begin(9600);
delay(1000);
Serial.println();
Serial.println("DFPlayer Mini Demo");
Serial.println("Initializing DFPlayer...");
if (!myDFPlayer.begin(mySoftwareSerial)) {
Serial.println("Unable to begin:");
Serial.println("1.Please recheck the connection!");
Serial.println("2.Please insert the SD card!");
while (true);
}
Serial.println(F("DFPlayer Mini online."));
myDFPlayer.setTimeOut(500);
//----Set volume----
myDFPlayer.volume(0); //Set volume value (0~30).
//myDFPlayer.volumeUp(); //Volume Up
//myDFPlayer.volumeDown(); //Volume Down
//----Set different EQ----
myDFPlayer.EQ(DFPLAYER_EQ_NORMAL);
// myDFPlayer.EQ(DFPLAYER_EQ_POP);
// myDFPlayer.EQ(DFPLAYER_EQ_ROCK);
// myDFPlayer.EQ(DFPLAYER_EQ_JAZZ);
// myDFPlayer.EQ(DFPLAYER_EQ_CLASSIC);
// myDFPlayer.EQ(DFPLAYER_EQ_BASS);
myDFPlayer.outputDevice(DFPLAYER_DEVICE_SD);
myDFPlayer.play(1); //Play the first song
isPlaying = true;
Serial.println("Playing..");
}
void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculating the distance
distance= duration*0.034/2;
// Prints the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.println(distance);
if (distance > 20 ){
myDFPlayer.pause();
}
if ( distance < 20 and distance > 0){
myDFPlayer.randomAll();
for (int i=0; i <= 30; i++){
myDFPlayer.volume(i);}
/* myDFPlayer.volume(5);
myDFPlayer.volume(6);
myDFPlayer.volume(7);
myDFPlayer.volume(8);
myDFPlayer.volume(9);
myDFPlayer.volume(10);
myDFPlayer.volume(11);
myDFPlayer.volume(12);
myDFPlayer.volume(13);
myDFPlayer.volume(14);
myDFPlayer.volume(15);
myDFPlayer.volume(16);
myDFPlayer.volume(17);
myDFPlayer.volume(18);
myDFPlayer.volume(19);
myDFPlayer.volume(20);
myDFPlayer.volume(21);
myDFPlayer.volume(22);
myDFPlayer.volume(23);
myDFPlayer.volume(24);
myDFPlayer.volume(25);
myDFPlayer.volume(26);
myDFPlayer.volume(27);
myDFPlayer.volume(28); */
delay(20000);
myDFPlayer.volume(28);
myDFPlayer.volume(27);
myDFPlayer.volume(26);
myDFPlayer.volume(25);
myDFPlayer.volume(24);
myDFPlayer.volume(23);
myDFPlayer.volume(22);
myDFPlayer.volume(21);
myDFPlayer.volume(20);
myDFPlayer.volume(19);
myDFPlayer.volume(18);
myDFPlayer.volume(17);
myDFPlayer.volume(16);
myDFPlayer.volume(15);
myDFPlayer.volume(14);
myDFPlayer.volume(13);
myDFPlayer.volume(12);
myDFPlayer.volume(11);
myDFPlayer.volume(10);
myDFPlayer.volume(9);
myDFPlayer.volume(8);
myDFPlayer.volume(7);
myDFPlayer.volume(6);
myDFPlayer.volume(5);
myDFPlayer.volume(4);
myDFPlayer.volume(3);
myDFPlayer.volume(2);
myDFPlayer.volume(1);
}
if (digitalRead(buttonPause) == LOW) {
if (isPlaying) {
myDFPlayer.pause();
isPlaying = false;
Serial.println("Paused..");
} else {
isPlaying = true;
myDFPlayer.start();
Serial.println("Playing..");
}
}
}