Hi! I'm scratching my head over a DFplayer mini which I can't seem to get working properly. The weird thing about it is that it works perfectly when i power my arduino uno with USB. The dfplayer is connected to its 5v pin. There's three triggers in my setup and every one of them should set off a specific mp3 on the SD card. I want the system to be powered through a 12v plug and i'm using a step down buck to send 7 volts into the VIN pin. I also tried sending 5v into the 5v pin. Now I have tried everything i could think of: Replace the arduino uno replace the DFplayer replace every single cable in the setup I do have a resistor in between the dfplayers RX pin I'm using softwareserial to do the communication. I will provide my code here, it is part of a puzzle i'm making. So there is additional non relevant code in it as well. The main focus is to figure out why this setup is working when powered thourh USB on my computer, but not with the external power source. if by some change someone spots the faulty part in my rfid tag, please let me know. that is an issue I want to resolve after this one :wink: (it reads A rfid tag, doesn't have to be secured, then open the relay pin. It works once, then it won't read it again) Thanks in advance if someone knows the answer to this! I have had no luck with googling this problem, as I have no idea what the source of the problem is. #include #include "Arduino.h" #include #include #include #define SS_PIN 10 #define RST_PIN 5 #define RELAY_PIN 8 // the Arduino pin connects to relay //setup voor dfplayer const int startknop = 6; const int key = 4; int startknopstaat; int currentkeystate; int lastkeystate; SoftwareSerial mySoftwareSerial (3, 9); // RX, TX DFRobotDFPlayerMini myDFPlayer; void printDetail(uint8_t type, int value); //setup voor RFID puzzel MFRC522 rfid(SS_PIN, RST_PIN); byte authorizedUID[4] = {0xFF, 0xFF, 0xFF, 0xFF}; //setup voor potmeter puzzel const int potmeter = A0; const int relais = 7; int potvalue; void setup() { delay(1000); //setup voor dfplayer pinMode(startknop, INPUT_PULLUP); pinMode(key, INPUT_PULLUP); 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!")); while (true); } Serial.println(F("DFPlayer Mini online.")); myDFPlayer.setTimeOut(3000); // setup voor RFID puzzel SPI.begin(); // init SPI bus rfid.PCD_Init(); // init MFRC522 pinMode(RELAY_PIN, OUTPUT); // initialize pin as an output. digitalWrite(RELAY_PIN, LOW); // deactivate the relay Serial.println("Tap RFID/NFC Tag on reader"); // setup voor potmeter puzzel pinMode(relais, OUTPUT); potvalue = analogRead(potmeter); delay(1000); } void loop() { //loop voor dfplayer startknopstaat = digitalRead(startknop); lastkeystate = currentkeystate; currentkeystate = digitalRead(key); if (startknopstaat == LOW) { myDFPlayer.volume(20); myDFPlayer.play(1); Serial.println("play 1"); delay(500); } if (lastkeystate == HIGH && currentkeystate == LOW) { myDFPlayer.volume(20); myDFPlayer.play(3); Serial.println("play 3"); delay(500); } //loop voor RFID puzzel if (! rfid.PICC_IsNewCardPresent()) { return; } else { Serial.println("hello world"); digitalWrite(RELAY_PIN, HIGH); delay(2000); digitalWrite(RELAY_PIN, LOW); myDFPlayer.volume(20); myDFPlayer.play(2); Serial.println("play 2"); delay(500); rfid.PICC_HaltA(); rfid.PCD_StopCrypto1(); } //loop voor potmeter puzzel potvalue = analogRead(potmeter); if (potvalue > 500) { digitalWrite(relais, HIGH); delay(100); } if (potvalue < 500) { digitalWrite(relais, LOW); delay(100); } }

[image] steven19111992: The main focus is to figure out why this setup is working when powered thourh USB on my computer, but not with the external power source. Please post a schematic. Include all components, their part numbers and/or values and all power supplies. Hand drawn, photographed and posted is fine if you have no CAD program. if you want to get started with a simple CAD program look here: [image] How to make a schematic you can post. Tutorials When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th… Also, please post the specifications of the external power supply(s). Output voltage and current capability, especially.

Hi thanks for your response, I tried to draw it, but that's not within my skill set. I took a picture and wrote down how it's connected. Hope you can use this! I'm using the next components: Arduino UNO R3 met ATmega328P-AU funduino mfrc522 rfid dfplayer mini 1K resistor on the DF's Rx line 12v powersupply is a Quintezz AC>DC with output 12V 3A LM317 DC-DC step-down DC converter and a keyswitch and arcadebutton to control the mp3 module. This is my connection: From DF player: VCC > 5V RX > resistor > 9~ TX > 3~ GND > GND SPK1 & SPK2 > speaker Startknop > 6 key > 4 From RFID MFRC522: 3.3V > 3.3V RST > 5 GND > GND NC > not connected MISO > 12 MOSI > 11~ SCK > 13 SDA > 10~ Relay1 > 8 Potmeter > A0 Relay2 = 7 [IMG_20220626_102444] EDIT I forgot to mention the exact fault. When plugged into the 12v power the DF player starts playing random mp3's. like it's being triggered very inconsistently. Sometimes every second, then 5 seconds, up to even 30 seconds of stability and then to be triggered again. And sometimes the triggers are so fast after each other that you don't even hear the mp3 playing, but you see the light blinking on the dfplayer. MOSTLY it is mp3 #3 that is playing, which should be triggered by the keyswitch. But it also tends to play something else, or even change the volume settings. EDIT 2 When I use USB power, but with a powerbank instead of my computer it also works perfectly.

Could you look at that photo and get to the heart of the matter? [image] steven19111992: I tried to draw it, but that's not within my skill set. What's so hard about rectangles and lines? What's needed is dismantling the whole business and then getting the Arduino running with the buck/SMPS. Once that is solid you can go on adding thus and sundry.

It may be a power issue. If its working fine on USB power with no issues- let's look at whatever a "Quintezz 12v power supply" is. Is it a REGULATED power supply? If not- then I would assume that would be your problem. Also my standard answer of :Did you buy an ACTUAL DFMini Mp3 player from DigiKey or DFRobot, or one of the knockoffs from Amazon, Ebay or AliExpress? For sure the knockoffs have some wonky power issues.

Hi halloweenrick, As far as I know it's a real DFRobot dfplayer. I swapped it with another one, as have I swapped the 'funduino' with a real arduino uno R3. But the problem stayed. Now I have done some testing and troubleshooting the last few days and I have come very close to the problem. If in my code I grey out the part where it looks at the keystate and plays mp3 #3, the problems gone. Also, when the code IS there, but I disconnect the wire from pin 4 (also the key switch) the problem is gone. So now i tried just connecting a wire to pin 4, not connecting the other end to anything and the problem is back again. If i put the other end to the 5v pin it's stable again. So now what I did: The key switch in OFF position connected to 5v, the keyswitch in ON position connected to GND. This makes it very very stable, the problem only occured once now. EDIT While typing this, my smartphone was on the table. When I received a message on it the mp3 began playing... WHAT? is there some sort of antenna error in this setup? EDIT 2 I just got a new 12v adapter and now it's working.

Issue with DFPlayer / external power supply

Other Hardware Audio

groundFungus June 25, 2022, 5:27pm 2

Please post a schematic. Include all components, their part numbers and/or values and all power supplies. Hand drawn, photographed and posted is fine if you have no CAD program. if you want to get started with a simple CAD program look here:

Also, please post the specifications of the external power supply(s). Output voltage and current capability, especially.

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Issue with DFPlayer / external power supply

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