Simple Arduino Audio Player and Amplifier with LM386

Published  June 26, 2017   118
Aswinth Raj
Simple Arduino Audio Player and Amplifier with LM386

Adding sounds or music to our project will always make it looks cool and sounds much more attractive. Especially if you are using an Arduino and you have lots of pins free, you can easily add sound effects to your project by just investing in an extra SD card module and a normal speaker. In this article I will show you how easy it is to Play music/add sound effects using your Arduino Board.  Thanks to the Arduino community who have developed some libraries to build this in a fast and easy way. We have also used IC LM386 here for amplification and noise cancelation purpose.

In this project, we will play the .wav music files stores in an SD card. We will program the Arduino to read these .wav files and play the audio on a speak through an LM386 Audio amplifier. Now, since this code could only read .wav files, technically this project cannot be called as an Arduino Mp3 Player, but hey you will still be able to hear songs with it. If you are looking for simple alternatives like an Arduio music player without SD card, you should check out the Arduino melody player which we have built earlier.  

Hardware Required:

  1. Arduino UNO
  2. SD Card Reader module
  3. SD card
  4. LM386 Audio Amplifier
  5. 10uf Capacitor (2 Nos)
  6. 100uf Capacitor (2 Nos)
  7. 1K,10K Resistor
  8. Push buttons (2 Nos)
  9. Breadboard
  10. Connecting Wires


Getting ready with your WAV audio files:

For playing sounds from SD Card using Arduino, we need audio files in .wav format because Arduino Board can play an audio file in a specific format that is wav format. To make an arduino mp3 player, there are a lot of mp3 shields are available which you can use with arduino. Or else to play mp3 files in arduino, there are websites which you can be used to convert any audio file on your computer into that specific WAV file.


So to convert any audio file into wav format, follow the below steps:


Step 1: Click on “Online Wav Converter” to enter into the website.


Step 2: Arduino can play a wav file in the following format. You can toy around with the settings later, but these settings were experiment to be the best in quality.


Bit Resolution

8 Bit

Sampling Rate

16000 Hz

Audio Channel


PCM format

PCM unsigned 8-bit


Step 3: In the website click on “choose file” and select the file you want to convert. Then feed in the above settings. Once done it should look something like this in the below image

converting audio files into wav format for playing using Arduino


Step 4:  Now, click on “Convert File” and your Audio file will be converter to .Wav file format. It will also be downloaded once the conversion is done.


Step 5: Finally format your SD card and save your .wav audio file into it. Make sure you format it before you add this file. Also remember the name of your audio file. Similarly you can select any of your four audios and save them with names 1, 2, 3 and 4(Names should not be changed). I have converted four songs and have saved them as 1.wav, 2.wav, 3.wav and 4.wav like shown below.

songs in wav format for playing using Arduino


Circuit and Hardware:

Circuit Diagram for this Arduino Audio File Player is simple. The complete circuit diagram is shown in the Image below.

Simple Arduino Audio Player with LM386 amplifier circuit diagram

As we know our audio files are saved into the SD card, hence we interface a SD card reader module with our Arduino. The Arduino and SD card communicate using the SPI communication protocol. Hence the Module is interfaced with the SPI pins of the Arduino as shown above in the diagram. It is further listed in the table below.


SD card module





Pin 12

MISO (Master In Slave out)

Pin 11

MOSI (Master Out Slave In)

Pin 13

SCK (Synchronous Clock)

Pin 4

CS (Chip Select)


Now the Arduino will be able to read the music file from the SD card and play it on the pin number 9. But the audio signals produced by the Arduino on pin 9 will not be audible much. Hence we amplify it by using the LM386 Low voltage Audio amplifier IC.

The amplifier shown above is designed for a Gain of 200 and the Vdd (pin 6) is powered by the 5V pin of the Arduino. If you want to increase/decrease the sound you can increase/decrease the voltage provided to this pin. It can withstand a maximum of 15V. Learn more about this 200 gain amplification configuration for LM386 here.

We also have two push buttons connected to the pin 2 and 3 of the Arduino. These switches are used to play the next track of the song and play/pause the music respectively. I have used these buttons just to demonstrate its abilities; you can play the song whenever required. Check the Demo Video at the end.


You can assemble this circuit completely over a Breadboard as shown in the picture below

Simple Arduino music Player fritzing breadboard image


Programming your Arduino:

Once we are ready with the Hardware and the SD card, we are just one step away playing those songs. Insert the card into your SD card module and follow the steps below.

Step 1: As said earlier we will be using a library to make this project work. The link for the library is given below. Click on it and select “Clone or download” and choose download as ZIP.


Step 2: Add this Zip file into your Arduino IDE by selecting Sketch->Include Library -> Add .ZIP Library as shown below and select the ZIP file that we just downloaded.

installing library for playing audio files using Arduino


Step 3: The complete program of the arduino music player project is given at the end of this article, simply copy it and paste it in the Arduino Program. Now, click on Upload and get ready to play your audio files.


The program is self explanatory since they have the comment lines. But, I have also explained the ability of the TMRpcm library below.


Playing an audio file:

You can play any audio that is stored in Wav format inside the SD card module by using the line below."3.wav");
//object (“FileName.wav”);

You can use this line at places where you want to trigger the Audio


Pause an audio File:

To pause an Audio file, you can simply call the line below.



Forwarding/Rewinding an Audio: 

There are not direct ways to forward or rewind an Audio file, but you can use the line below to play a song at a particular time. This can be used to forward/rewind with some additional programming."2.wav",33); //Plays the song from 33rd second
//“Filename.wav”,time in second);


Setting the quality of the audio:

The library gives us two qualities to play the music, one is to play as normal mode the other to play with 2X oversampling.

music.quality(0); //Normal Mode
music.quality(1); //2X over sampling mode


Setting the Volume of the audio:

Yes, you can control the volume of the audio through software. You can simply set the volume by using the line below. Higher music volumes tend to affect the quality of the audio, hence use hardware control when possible.

music.setVolume(5);        //Plays the song at volume 5
//objectname.setVolume(Volume level);


Working of this Arduino Music Player:

After programming your Arduino simply press the button connected to pin 2 and your Arduino will play the first song (saved as 1.wav) for you.  Now you can press the button again to change your track to the next song that is to play 2.wav. Likewise you can navigate to all four songs.

You can also play/Pause the song by pressing the button connected to pin 3. Press it once to pause the song and press it again to play it from where it stopped.  Watch the video below for complete working (or maybe to relax yourself with some songs).

playing songs from SD card using Arduino

Hope you enjoyed the project. Now it is up to your creativity to use them in your projects. You can make a speaking clock, voice assistant, talking robot, voice alert security system and much more. Let me know how you are planning to use it through the comment section and also if you have any problems in getting this thing work you can reach me through the forums or the comment section below.


Arduino Based Music Player

 This example shows how to play three songs from SD card by pressing a push button

 The circuit:
 * Push Button on pin 2 and 3
 * Audio Out - pin 9
 * SD card attached to SPI bus as follows:
 ** MOSI - pin 11
 ** MISO - pin 12
 ** CLK - pin 13
 ** CS - pin 4 

 created  25 Jun 2017
 by Aswinth Raj

 This example code was created for

#include "SD.h" //Lib to read SD card
#include "TMRpcm.h" //Lib to play auido
#include "SPI.h" //SPI lib for SD card

#define SD_ChipSelectPin 4 //Chip select is pin number 4
TMRpcm music; //Lib object is named "music"

int song_number=0;
boolean debounce1=true;
boolean debounce2=true;
boolean play_pause;

void setup(){
music.speakerPin = 9; //Auido out on pin 9
Serial.begin(9600); //Serial Com for debugging 
if (!SD.begin(SD_ChipSelectPin)) {
Serial.println("SD fail");

pinMode(2, INPUT_PULLUP); //Button 1 with internal pull up to chage track
pinMode(3, INPUT_PULLUP); //Button 2 with internal pull up to play/pause
pinMode(3, INPUT_PULLUP); //Button 2 with internal pull up to fast forward

music.setVolume(5);    //   0 to 7. Set volume level
music.quality(1);        //  Set 1 for 2x oversampling Set 0 for normal
//music.volume(0);        //   1(up) or 0(down) to control volume
//"filename",30); plays a file starting at 30 seconds into the track    

void loop()

  if (digitalRead(2)==LOW  && debounce1 == true) //Button 1 Pressed
  if (song_number==5)
  Serial.println("KEY PRESSED");

  if (song_number ==1)
  {"1.wav",10);} //Play song 1 from 10th second 

  if (song_number ==2)
  {"2.wav",33);} //Play song 2 from 33rd second 

  if (song_number ==3)
  {"3.wav");} //Play song 3 from start

  if (song_number ==4)
  {"4.wav",25);} //Play song 4 from 25th second 

  if (digitalRead(3)==LOW  && debounce2 == true) //Button 2 Pressed
  music.pause();  Serial.println("PLAY / PAUSE");

  if (digitalRead(2)==HIGH) //Avoid debounce

  if (digitalRead(3)==HIGH)//Avoid debounce




Submitted by Lorenzo on Sat, 09/02/2017 - 21:57


hey, I see in your fritzing pic you put the ground in the + line and the + in the ground line, but the speaker's black wire is connected to the breadbard's blue line (where is connected 5V) and the red wire to the red line (where is connected gnd). Where should I connect amplifier pins?

Hi Miles, The above problem is not because of the program but because of your PORT settings. As the error states "can't open device "COM1": No such file or directory" Meaning you have either not selected the correct COM port or have not connected Arduino to PC properly. Try uploading a Blink program to verify your settings before trying this program. Thanks!

Submitted by Luke Barker on Fri, 09/29/2017 - 02:53


Will this work without the LM386 and go direct to head phones?

Submitted by Noam on Mon, 10/09/2017 - 01:56



I was able to purchase pololu microSD card breakout board with a 3.3V regulator and level shifters and I am getting error (SD Fail)

Is it related to Module vendor ?

Best regards


So you have a 3.3V module with 5V level shifter right?

Make sure the level shifter is working by manually measuirng voltage. 

The can be either because of your connections or because of your module

Submitted by fitri hanun on Fri, 10/13/2017 - 05:07


Hi. i got this error /Users/milesrichie/Documents/Arduino/sketch_sep10a/sketch_sep10a.ino: In function 'void loop()':
/Users/fitrihanun/Documents/Arduino/sketch_sep10a/sketch_sep10a.ino:54:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
{"1.wav",10);} //Play song 1 from 10th second
/Users/fitrihanun/Documents/Arduino/sketch_sep10a/sketch_sep10a.ino:56:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
{"2.wav",33);} //Play song 2 from 33rd second
/Users/fitrihanun/Documents/Arduino/sketch_sep10a/sketch_sep10a.ino:58:22: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
{"3.wav");} //Play song 3 from start
/Users/fitrihanun/Documents/Arduino/sketch_sep10a/sketch_sep10a.ino:60:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
{"4.wav",25);} //Play song 4 from 25th second }

Submitted by ANAND on Sun, 10/15/2017 - 22:31


hI,can i use this library with atmega 8 mcu.I tried it but it shows some "exit status 1
Error compiling for board Arduino NG or older."

Submitted by jim on Mon, 10/23/2017 - 22:04


Mr Raj. it was a wonderful example. I am thinking to revise the code, but this time using only a single button to turn on and off the music. Here is what i want, im going to used a toggle switch ( on and off). When the button is closed(permanently closed) ,the music will play. When the button is press again the button will be open and the music will stop. However, i wanted to play the music from start again when the button is closed again. Can you help me on this. many thanks

Submitted by Kyle on Tue, 11/07/2017 - 17:18


Hi, I am looking to build something like this, but with an option to play one of four .wav files. Is it fairly simple to instead have four buttons to play an audio track, and another to stop. Pressing of any button halting any other .wav file and playing just the programmed .wav file?
Would appreciate any help as it is for a non-profit group that I help out

Submitted by Nagarajan on Tue, 11/21/2017 - 10:57


Sir, Will you please give me a sample coding for arduino program to play the audio files one by one at exact pre- scheduled time interval and switch off as the song ends.

Submitted by robert linder on Thu, 11/30/2017 - 02:07


hi i think ive wired everything correctly but no sound is coming out except an occasional tap? and my lm386 chip is getting really hot.
im trying to make it so that i can move the buttons off away from the breadboard if possible.

update the heating problem is fixed but no music is playing when i press the buttons only a tap. checked sd card is being read ok and files are found but still cant get music to play. any suggestions would be helpful

ok final update before my head explodes!
im getting a warning about the files when i compile which reads;
warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

repeats for other files
ive looked on the forums and responses just make me more confused as i dont know how to apply the changes they suggest out of the context theyre suggested in. (if that makes sense)
something along the lines of making the song files constants?
could this be why my files wont play?

I not sure how you ended up on his error. But was the code working for you properly the first time. I assume the Amplifier was heating mostly because of a wrong connection. When you rectified the correction the IC might have been completely burnt. So try replacing the IC, incase if you dont have one ignore the amplifier part they will still work just fine but sound will be low.  I tried compiling the same code given here, yet dint get the error you are speaking about

Submitted by SimK on Thu, 01/04/2018 - 02:20


How would you connect a speaker using bluetooth module HC06? I am unsure of how to do this.
Thanks :)

Submitted by Recai on Wed, 01/10/2018 - 11:19


Hi. How is it possible to for arduino to give smooth analog signal for music since it can only produce pwm? Can you answer me please. I am confused.

Submitted by jim on Sat, 01/13/2018 - 15:15


Hello Mr. Raj.
I was successful in doing the same. However, everytime i press the buttton to play the music i can a loud ticking sound in which i believed coming from the switch. Is there anyway i can eliminate this "click" sound.

Submitted by Anant Maind on Fri, 01/19/2018 - 16:34


Default test file provided in library plays well.But another file not playes properly even i have convered as per your suggestion like

1. into .wav
2.sample :1600Hz
3.Channel :Mono
4.Bits 8

Advance pcm format :PCM unsigned 8 bit

Submitted by Awan on Wed, 01/24/2018 - 09:22


hello sir my name is awan first sorry to interrupt your time, what kind a speaker when you use in this project because from this tutorial I can't rise up my volume and noise everywhere when I play the music

Submitted by Mr Manjunatha on Sat, 01/27/2018 - 00:34


SD fail
(in serial monitor)
the memory card is ok and formatted also.

I am getting this errors
please reply for me as soon as possible

Submitted by A.M.L on Thu, 02/01/2018 - 20:30


hey thanks, but i have a problem ....... when i push the push button first time , track 1 play but when i push it the second ,track 2 didn't play please tell me why and thank you

Submitted by henry on Tue, 02/06/2018 - 03:38


Can you specify where the error is in the fritzing diagram? I am trying to build this circuit based off the fritzing, but earlier comments make is seem like the fritzing is inaccurate.

Submitted by jun sarte on Mon, 02/12/2018 - 22:29


i have a problem when i am trying to change track it will not work when i press again the button

Submitted by SimK on Thu, 02/15/2018 - 05:05


How would you connect a speaker using bluetooth module HC06? I am unsure of how to do this.
Thanks :)

Submitted by Gian.Luke on Sun, 02/18/2018 - 16:33


Hi, thanks for posting this project. I have a question. What's the purpose of putting a 10k resistor in series with a 10uF capacitor to ground at the output? Usually a low resistance (10ohm) and low capacitance (0.05uF) are used in that manner to filter out high frequencies. I think that way you filter out also desired frequencies. Let me know please. Thank you.

Submitted by Henry on Tue, 02/20/2018 - 06:28


Can you please CLEARLY specify where the errors are in the breadboard diagram? I am having trouble building the circuit and would like to use the breadboard diagram instead of the schematic. Are there any errors in the schematic, or can I build safely off of that?

Submitted by Saddam Hossain on Tue, 02/20/2018 - 11:25


You have done a very good job. I am also doing a project like this. I want to add one more button for stopping the music. I tried with the "audio.stopPlayback(); " function . But is not working properly. Do have any idea how to fix this?
Say, in your current project if you add one more button then what will be the code for stopping the music?

Submitted by Vanshree Bapat on Thu, 03/01/2018 - 09:01


Hi. We are currently working on a project to convert ASL into normal speech using Arduino mega 2560. The code and the connections are exactly as given on various sites (CS pin 53 on mega), but at each time it is failing to initialise. Please help us if possible! Thank You

Submitted by Ranjeet on Fri, 03/02/2018 - 13:33


I connected everything and put code on arduino but it doesnt play the music. You can just hear some noise, buttons do nothing, Whats the problem?

Submitted by Divya on Sat, 03/03/2018 - 15:46


hlo, I have tried all the things u have mentioned in ur list. But v r unable to get the audio from the speaker. We hve used a 3ohm speaker. We are getting mgs on monitor screen as"KEY PRESSED
song_number=1". And no any sound is heard. Can u plz help us out wdt this issue.

Submitted by Siege on Wed, 03/28/2018 - 14:00


C:\Users\Acer\Documents\Arduino\sketch_mar21a\sketch_mar21a.ino: In function 'void loop()':

C:\Users\Acer\Documents\Arduino\sketch_mar21a\sketch_mar21a.ino:66:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

{"1.wav",10);} //Play song 1 from 10th second


C:\Users\Acer\Documents\Arduino\sketch_mar21a\sketch_mar21a.ino:69:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

{"2.wav",33);} //Play song 2 from 33rd second


C:\Users\Acer\Documents\Arduino\sketch_mar21a\sketch_mar21a.ino:72:22: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

{"3.wav");} //Play song 3 from start


C:\Users\Acer\Documents\Arduino\sketch_mar21a\sketch_mar21a.ino:75:25: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

{"4.wav",25);} //Play song 4 from 25th second


Submitted by Denny on Sat, 03/31/2018 - 00:03


Mr Raj, Thank you very much for this project. I found this is very useful and cost saving (no buying mp3 shield), I will build mini music player for my kids.
thank you :)

Submitted by Karl on Fri, 04/06/2018 - 11:18


Hey, there is something not clear in the circuit. Are pins 2 and 4 of the amplifier connected to the positive pin of the speaker? Because in the arduino picture it's not showing

Submitted by Karl on Thu, 04/12/2018 - 09:24


Hey, thanks a lot for the project! However, I am having trouble when the music starts playing, sometimes songs just start fast forwarding alone and skipping parts. Also the the code just stops sometimes when the skipping gets really bad. Is this a problem with the wires? or the sampling of my wav files?

Submitted by freakman on Wed, 04/25/2018 - 01:49


Hi! Can I use a PAM8403 to amplify the sound?

Submitted by lyramaranan on Wed, 04/25/2018 - 12:46


hello, i just want to us if it is possible to control the speed of the stepper motor using the music mp3 plays? and how if it is possible, i need that on our project, i just want to know if it is possible because our professor want our project music box to control the rotation of the balerina through the beat of music, for example the music is upbeat therefore the balerina rotates fast and if the music is slow, the balerina rotates slowly. Thank you.

Submitted by Kughaneshwaran on Fri, 04/27/2018 - 09:13


Does the capacitor have to be 25 V or any other voltage

Submitted by mohid on Sun, 05/13/2018 - 22:29


Hi, can you tell me how to increase the volume through hardware.can i do it either by changing capacitors or increase power to the circuit or any other ways you know? thanks!

Submitted by Haider Ali on Sun, 05/20/2018 - 16:03


The errors occurred in the code given above is due to function typecasting is required in this function"4.wav",25);
Corrected function argument is: *)"4.wav",25);

Not everyone (even the experienced)  gets a circuit to work in the first try. Learn to debug a circuit when you don't get an output, this is an important skill in electronics. So break the circuit into smaller parts and check where the output is messing up.

In this case bypass the amplifier section and connect the speaker directly to check if you are getting any audio

Not everyone (even the experienced)  gets a circuit to work in the first try. Learn to debug a circuit when you don't get an output, this is an important skill in electronics. So break the circuit into smaller parts and check where the output is messing up.

In this case bypass the amplifier section and connect the speaker directly to check if you are getting any audio

Not everyone (even the experienced)  gets a circuit to work in the first try. Learn to debug a circuit when you don't get an output, this is an important skill in electronics. So break the circuit into smaller parts and check where the output is messing up.

In this case bypass the amplifier section and connect the speaker directly to check if you are getting any audio

Submitted by Tim on Thu, 06/14/2018 - 20:24


Hi, its not entirely clear to me regarding the connections to the push buttons. Do both buttons have a connection to GND and then to the pins 2 and 3 respectively? So the idea is that pulling those pins to GND will trigger the appropriate function?


Submitted by kamz on Sat, 06/23/2018 - 02:31


hi, I have a built audio amplifer. the Haljia LM386. it has 2 gnd one in and one VDD. which wires to I connect in this connection