Introduction: The SWD >> a Sleep Well Device

A device to play nice sound e.g. rain, waves, jungle to sleep better.

One charge will play (set to a moderate volume) up to 8 hours!

This a "how to" build a tiny rechargeable MP3 player.

The box I used is 8.5 x 7 x 4 cm.

The idea was to build the internal electronics as accurate as a mechanical clockwork is build- :-)

And like a mechanical clockwork I like to have such tiny pull switch to activate it.

I published a similar instructable a couple of month ago. But I like to have smaller and rechargeable.


  • Small wooden box
  • Small LiPo akku
  • LiPo charger
  • MP3 module
  • Micro SD - card
  • 2 push buttons
  • Tiny slide switch
  • Small speaker 4 - 8 Ohms that fits to MP3 modul
  • Some "bits and pieces"
  • WAX stain
  • Hammerit paint in green
  • 4 Bras feet
  • Round metal rod 2mm for on/off switch

OK, got your material?

Then follow me into my workshop...

Step 1: Preparing the Box

First prepare the box.

Place all parts temporary inside the box to find good positions for it. Pleas keep in mind that the SD - card would be changed eventually. ;-)

I disassembled the box to make working on it a bit easier.

After finding the right position for each part, I drilled all the holes and

painted the lower part of the box with prepaint.

After this I filed the slot for LiPo charger.

Step 2: Preparing the Switch and the MP3 Player

I drilled a hole trough the handle of the switch a bit smaller than the metal rod so it will fit very tight and no gluing is necessary.

The switch was glued to a piece of wood to level it up. Than a hole was drilled trough the front. (see picture 3)

To make th echanging of the SD - card a bit easier I leveled the MP3 module a bit up as well.

Step 3: Painting

I painted the upper part of the case with wax stain and the lower part with green Hammerit lack.

Than the brass feeds and the speaker cover where mounted.

The push buttons are glued and will be operated underneath the case.

Step 4: Mounting Everythin in Place

A components are glued in place.

  • LiPo charger
  • LiPo akku
  • MP3 module
  • Push buttons
  • Speaker
  • On/off switch

The LiPo akku was glued with a easy to remove double sided tape. So it can be renewed a bit easier.

Some words of warning regarding LiPos!

Be very careful if working with LiPos.

  • Never charge it without a LiPo charger.
  • Don´t short the terminals
  • Do not physically damage a LiPo
  • Do not overheat it

Step 5: Final Wirings

I used stiff wires to connect GND and the push buttons an flexible wires for the speaker connection.


Then start charging an enjoy the sound:-)