Introduction: MP3 Music Player

This instructtable will describe how to make a mp3 player.

For a school assignment i have to make an object. The object needs to meet a number of requirements.

  • It needs to contain a hinge
  • It has to contain an electrical connection
  • It has to be made with a 3D printer, a laser cutter and 1 other device of choice.

At first, i was thinking about a useless box, but then the teacher told our class that there is 1 thing we are not allowed to make, and that is a useless box. So i had to think of another object. Then i came up with a hovercraft. But after looking at the components i needed, it looks like it will cost a lot of money.

After that, i turned to my room at home and looked around for stuff that is possible to make. I saw my speaker, and thought about how i play music. That is by starting my computer, connecting it to my speaker via Bluetooth and then play music. That is how i came up with what i was going to make. I wanted to combine all this features and go back in time a little and make a mp3 player.

A project on Instructables that looks like mine, is this one.

For this project i am using a few tools:

  • Laser cutter
  • 3D printer
  • Glue gun
  • Screwdriver
  • Soldering Iron

MoSCoW analysis

Must

  • Speaker
  • On-off switch
  • Hinge (for on-off switch)
  • MP3 player

Should

  • Speaker
  • USB or SD card support
  • Lights

Could

  • Power Lights
  • Audio jack support

Would

  • Lights that respond on the music playing

Step 1: Things You Need

  1. 3mm thick wood planks (to cut with laser cutter)
  2. DFPlayer Mini MP3 Player Module (buy here)
  3. Breadboard (buy here)
  4. Breadboard electricity cables (buy here)
  5. 3 Tactile buttons with capps (buy here)
  6. 33k ohm resistor
  7. Micro SD card (max 32gb)
  8. Speakers (buy here)
  9. Battery pack between 3.3V and 6V (buy here)
  10. small hinge
  11. 12x 3mm diameter screws (and about 1cm tall)
  12. 12x 3mm diameter nuts

Step 2: Setting Up the SD Card

  1. Format your SD card to FAT32 standard
  2. Make a folder called "mp3" (without the quotes) in the root of the SD card
  3. Place mp3 files in the folder
  4. Make sure all audio files start with a unique 4 digit number, for example
    • 0001.mp3
    • 0002 - Adele - Hello
    • 0003MichaelJacksonBeatIt
  5. Put the SD card inside the Mini MP3 Module

Step 3: The Electricity Scheme

It is now time set connect all the electronics. To do so, please take a look at the image. NOTE: I use a 4x AA battery pack, so the battery pack is different!

After connecting all te pieces, make sure the design is as flat as possible. That means that you have to press your resistor to your breadboard. Also try to bend the wire pins so they are also as flat as possible.

Use the soldering iron to make sure the cables cannot disconnnect from the speakers.

Check if your design works. Put the prepared SD card inside the mp3 module. Press the right button 3 times. Music should start playing. Check if all buttons work correctly:

  • Left button click should go to previous song
  • Left button hold should lower the volume
  • Middle button click should play/pause the song
  • Right button click should go to next song
  • Right button hold should increase the volume

Explained

The mp3 player module is able to play music on its own, it does not need an Arduino to do this. The only thing it needs is a power source of 3.3V-6V, that is connected to the VCC and gnd in/outputs.

A maximum of 2 speakers can be connected on the + side to the SPK_1 and SPK_2 outputs. The - side of the speakers goes back to the gnd.

to control the music player, you need buttons. The IO_1 and IO_2 outputs are easy to connect. They give a predifined voltage, that has to go back to the gnd input of the mp3 module. The play/pause button is another story.

Via the ADKEY_1 output you can attach multiple buttons. The mp3player knows witch action to take, because of the resistor you place. If you place a 33k ohm resistor, the button will play/pause the music.

Step 4: Cutting the Box

To make the box, find a laser cutter you can use. Download the design of the box and use the laser cutter to cut the 3mm thick wood.

NOTE: Red lines are cutting lines, black lines are engraving lines

Attachments

Step 5: 3D Printing the Inside Support

Print out the 3D design with a 3D printer.

Some boxes/parts used could be different than what i used.

In that case, edit the 3D design so it fits your box.

When a part is to big, you can use sandpaper to scrape a little bit of.

Attachments

Step 6: Putting Everything Together

  1. Use 8 screws and nuts to screw the speakers in the sides. (image 1+2)
  2. Glue the sides to the bottom. Use your breadboard to make sure that the distance between the 2 sides is right so the breadboard fits in between(image 3)
  3. Screw the lid to the back using the hinge (image 4)
  4. Glue the back to the sides and the bottom (image 5)
  5. Glue the front to the sides and the bottom of the box (image 6)
  6. Place the 3D printed main battery support inside the box and glue the main battery support to the left side of the box (image 7)
  7. Place the battery (image 8)
  8. Use the dremel to cut the ends of the screws (image 9)
  9. Done!

Step 7: Play Your Music!

  1. Put your micro-SD card in the mp3 player
  2. Turn on your device
  3. Load the micro-SD card by clicking 3 times on the right button

Controls:

  • Loading micro-SD card: 3x click right button
  • Play/pause: 1x click middle button
  • Previous song: 1x click left button
  • Next song: 1x click right button
  • Volume down: Hold left button
  • Volume up: Hold right button

Step 8: Tips, Tricks and Extra's

Tips & Tricks
  • What i found out was that the mp3 player was sometimes making weard noises when a button was clicked. This is because the mp3 player runs on 3.3V, and you supply it with a different voltage. To remove the cracking noises, change the battery voltage.
  • When i shake the mp3 player a little, the sound also gets cracky sometimes. This is caused by loose wire connections to the speakers. The easy way to solve is to use a soldering iron and solder the wires to the speaker.
  • Another thing that happened to me was that the 3d printed battery support does not perfectly fit in eachother. You can use sand paper to solve this.

Extra's

  • You can try to connect a 3.5mm audio port to the mp3 module