Introduction: Portable MP3 Player

About: i love retro stuff and music, i create to inspire others to do the same. i try my best to give people a lesson they will never forget...and yet im just a normal studen :-)

I consider myself a dedicated audiophile and i really never had my own mp3 player, so ofc as an inventor i created my own from parts you usually find in broken gadgets and parts you can buy.


The case may depend for you. I made mine with acrylic glass so that i can show people how it works without removing the whole case. I wanted a small thin portable object that i can bring and put in my pocket without any problems.

You may create your own design if you want. i made mine simple so that others can copy it easily.

Step 1: You'll Need Parts

as i mentioned some parts will be resued from broken stuff like earphones and controllers, etc.

Parts List:

-1x PowerBoost 500c
-1x MP3 Bluetooth Audio Reciever Deconding Player
(you can find cheaper ones that are not bluetooth. I preffer this one so i can have more choices other than have less choices)

-5x M3 20mm + 6mm Hollow Hex Cylinder

-4x M3 6mm + 6mm Hollow Hex Cylinder

-9x M3 Nuts

-9x M3 Screws (as short as posible if your using acrylic)

-1x Mic (from a pair of broken earphones)

-1x Switch (you can use once from rc controllers )

-1x Audio Jack Input 2.5 (i got mine from a headphone input splitter)

-1x Acrylic glass (big enough to make 2 sides)

-Popsicle sticks (you may need a lot)

-1x 800mah 1cell 3.7v Lipo Battery (you can use the 1000mah but it wont fit properly under the decoder)

Step 2: Circuit

sadly im not talented to make a diagram soo...


1. solder 2 wires on 2 of the switch tabs.

2. solder 1 wire to the EN tab on the Powerboost.

3. solder the other wire to the Grd tab next to EN.

4. Get your Decoding mp3 board. Flip it upside down. find the 5v and Gnd tabs.

5. solder 1 wire on each 5v and Gnd.

6. solder the other end of the 5v wire to the 5v output of the Powerboost.

7. solder the otehr end of the Gnd wire to any ground tab on the Powerboost.

8. attach the batter to the Powerboost.

9. flip the switch to see if it turns on/off.

10. add some solder on teh pads right beside the aux port on the decoder mp3 player.

11. solder a wire on each 3 pads. (looking at the decoder pmp3 player ( usb and sd card slots on top and micro usb slot on teh bottom) solder 2 red wires on teh first 2 pads right beside the aux port. then a black wire for the last pad.) so 3 pads right beside the aux port on the decoder. 2 red wires for the first 2 pads then the black wire for the last. teh 2 red wires are left side and rigth side.

12. solder the wires from step 11 to the aux jack. (depending if you are resourceful or just bought may need to look for a diagram of the order of wires.)

13. find the word mic on the decoder mp3 player and tehre should be 2 holes youc an solder on.

14. solder 2 wires on those 2 holes.

15. solder teh ends of those wires to the mic. ( MAKE SURE ITS + to + and - to -...if not your mic will not work properly...but dont worry it wont braek your board :-) )

16. Make your case.

17. put it all together and

18. TADA youre done!!

Step 3: My Case

again i have no diagram for this soo...

Sideplate 1 (bottom):

4.25" x 2.25"


1. drill holes on corners of the Top Left, Bottom right, Bottom left and the middle of the right side.

2. for the top right, move 0.8 cm from the right side

3. drill holes that are 3.5 cm near the right side (just bellow the 2 holes you made earlier)

4. drill 2 more holes but 4 cm from the holes you made a second ago (to the left)

5. attach the M3 20mm Hollow Hex Cylinders on the 4 holes you made earlier and use screws

6. attach the M3 6mm Hollow Hex Cylinder on the next 4 holes you made and also use the screws

(if you are using a 800mah battery you may now put it underneath between the 6mm Hollow Hex Cylinder

but on the decoding mp3 player and use the M3 Nuts to secure it.

7. use bouble sided tape to attach the Powerboost on the acrylic glass


SIdeplate 2( top):

4.25" x 2.25"


7. drill the same 5 holes on step 1 for the bottom plate ( i advice that i just stacked 1 acrylic glasses togetehr and drilled it together so it would be the same)

8. cut a notch on the top right side that will allow the buttons to be accessable,. (thi sis teh reason why that top right M3 20mm Hollow Hex Cylinder was moved)

9. cut a popsicle stick that would fit in between the middle M3 20mm Hollow Hex Cylinder and the bottom right one.

10. drill holes on that that would fit teh mic and the aux jack(this took me a while)

11. attach the aux jack and mic on and glue the popsicle stick between the Hollow Hex Cylinders

12. cut another popsicle stick that would fit between the bottom left and bottm right M3 20mm Hollow Hex Cylinder

13. drill a hole that would fit your switch and attach it on

14. glue that popsicle stick between the Hollow Hex Cylinder

15. then lastly put on that top plate on top of the 5 M3 20mm Hollow Hex Cylinders and attach M3 Nuts to them.


Step 4: Additional Step I Did for Mine

i wanted a turn knob and amplifier for my volume so what i did was...

New Part: Amplifier with Potentiometer (i used the PAM 804 uses 5v like the decoder)

1. drill another hole beside the switch

2. attach the appropriate wires (i suggest looking up a diagram cause this can get confusing)


in teh picture of the mp3 player complete, it did not have the amplifier due to it being broken... which is also why there is only a Potentiometer instead of an amplifier.

Step 5: Results

Based from my testing i found that:
1. with a 800mah 1cell Lipo Battery, it lasted about 10 hours on a full charge (while on max volume teh whole time) Which is plenty of time for me personally.

2. using nylon stand offs instead of tape under the Powerboost looks more asthetic :-) .

3. Its fun to build and i hope you had fun too

PS. this will be one of my new projects that i will be making called Project Pulsate
it is dedicated to create new ways of enjoying music...stay tuned :-)

Invention Challenge 2017

Participated in the
Invention Challenge 2017