DFPlayer & Adafruit Feather 32u4 Fona

Hello !

I'm using the Adafruit Feather Fona to send information through mobile network, and I would like to add an audio module to send sounds as responses to the user.
I use the DFPlayer mini module (DFPlayer Mini Mp3 Player - DFRobot Wiki) + one 1W speaker.
I did the wiring as explained on the website to try to make the getting started example works.
My wiring :

• the VCC pin on my 3.7V battery
• the two GND pins on the battery GND
• the 2 speaker's wires on both SPK_1 and SPK_2 (I tried to put on SPK_1 and GND and I had the same problem)

With this configuration, the module plays the 2 sounds on y SD Card when I put the IO_1 to the GND.

Then, I tried to plug it on my Feather Fona, with the Rx and Tx pins :

• Rx on the A4 pin with a 1K resistor.
• Tx on the A5 pin with a 1K resistor.

(I also tried to put Tx and Rx on different pins like 9 and 10, A3 and 10, A3 and A4).

I try to run the example program coming with the library. I setup mySerial like this :

// ...
SoftwareSerial mySoftwareSerial(A4, A5); // RX, TX
DFRobotDFPlayerMini myDFPlayer;
void printDetail(uint8_t type, int value);

void setup()
{
  mySoftwareSerial.begin(9600);
  Serial.begin(115200);
  
  Serial.println();
  Serial.println(F("DFRobot DFPlayer Mini Demo"));
  Serial.println(F("Initializing DFPlayer ... (May take 3~5 seconds)"));
  
  if (!myDFPlayer.begin(mySoftwareSerial)) {  //Use softwareSerial to communicate with mp3.
    Serial.println(F("Unable to begin:"));
    Serial.println(F("1.Please recheck the connection!"));
    Serial.println(F("2.Please insert the SD card!"));
    Serial.println(myDFPlayer.begin(mySoftwareSerial));
    while(true){
      delay(0); // Code to compatible with ESP8266 watch dog.
    }
  }
  Serial.println(F("DFPlayer Mini online."));
  
  myDFPlayer.volume(10);  //Set volume value. From 0 to 30
  myDFPlayer.play(1);  //Play the first mp3
}
// ...

When I run the example program, it fails at the beginning saying :
Unable to begin:
1.Please recheck the connection!
2.Please insert the SD card!

When i print the return of myDFPlayer.begin, I always get 0.

I don't think it's the SD Card because it works when i use the IO pin, and I checked the Rx and Tx wiring, by measuring. I don't know where to look at right now !

Thnaks in advance!

ok, after several tests, I realized that I had two problems :

1. The Ax pins does not work with this module, so i tried again on the 10 and 11 pins and it work, as well as the 6.
2. My SoftwareSerial config was wrong : I had to invert Rx and Tx pin number in the config. So : if you wire the Rx pin to the module to the pin 10, and you wire the Tx pin to the pin 11, your config should look like : SoftwareSerial mySoftwareSerial(11, 10);

With this in mind, I can have it working !

This thread was helpful to me while trying to combine the Feather 32u4 Bluefruit with an DFPlayer Mini. I spent a while trying to figure out why the serial connection wasn't working with this board as it was on an Uno running at 5v even though the DFPlayer Mini claims to run on 3.3 - 5v.

Determined that the Mini just does not run correctly on the 3.3v out from the Feather.

It was confusing because it sort of worked, some of the time.

Powering it from the 3.7v battery's voltage pin gave it enough juice to run properly and made all the difference. (VBAT in this diagram: Adafruit Learning System).

I read the original post many times in which the author mentions using the battery's voltage pin and blithely ignoring that detail before stumbling on the same solution, so repeating it here in hopes it helps someone else.

Cheers!