Blueprint

MP3 Decoder

Its a MP3 Player/Decoder made using Atmega328p and DFrobot MP3 decoder. Also has a Option to add a OLED display to it

Created by Anshuman Tripathy Anshuman Tripathy

Tier 4

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1 follower

Timeline

koeg koeg šŸš€ gave kudos to MP3 Decoder ago

Really cool!

Anshuman Tripathy Anshuman Tripathy added to the journal ago

PCB assembly and testing done

So i completed the pcb assembly and doing a trial run with the board

it works great just uploading the bootloader onto the Atmega chip was a bit tedious however completed it and test using the sample code on the website.

here are a few thing i need to fix in the next version if i make one.

  1. The temp pin of the tp4056 ic needs to be grounded instead of being left open since it puss that pin to a random value and doesnt allow the battery to be charged
  2. i need to route the next and prev buttons to one of the io pins of the atmega chip since earlier i had it on the adkey mode of the df player which when pressed puts board in a where it no longer receives commands from the mcu
  3. one of the most obvious this i missed is adding a switch to turn off the 5v from the boost ic directly since now whenever i charge the board the board stays on permanently so to overcome that i have temporarily added a button combination to put the df player to sleep.

in the image u can see that ive added jumpers to the board for connecting the pay pause button to the mcu directly.

i havent yet tested the OLED display with it since i have my exams comming up so it will be a while before i test it

IMG_20251120_122742

deltea deltea šŸš€ gave kudos to MP3 Decoder ago

yo this is sick, i’m also trying to make a mp3 player

CAN CAN āš”šŸš€ approved MP3 Decoder ago

Tickets awarded: 176 tickets

Tier: 3

Anshuman Tripathy Anshuman Tripathy submitted MP3 Decoder for review ago

Anshuman Tripathy Anshuman Tripathy added to the journal ago

Completing the CAD

Added Holes for the Switch and the charging indicator also raised the overall height to house the battery inside of it too.

Also designed the top also made proper housing for the OLED display in it.

imageScreenshot 2025-10-26 191618

Anshuman Tripathy Anshuman Tripathy added to the journal ago

Made the Base of the model

Made the rough part of the base also put in the 3d board for referencing.
planning to use heatset inserts for fixing the PCB to base.
thinking to attach the top directly to the body since i dont want to made the walls of the case thick.

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Anshuman Tripathy Anshuman Tripathy added to the journal ago

started with the 3d model

imported the DXF from kicad to exactly match the positions of the holes on the pcb since they are not uniformly placed. planning to keep 4mm borders but still not sure how i will screw them in place since the screws i have have a big head maybe will get some counter sunk ones.
here is the sketch image

Anshuman Tripathy Anshuman Tripathy added to the journal ago

Completed the PCB more or less

Added all the pin labels multiple ground vias. i also decided to add a test point for 5v since i am using a mt3608 voltage booster ic so before i assemble the rest of the components i need to check if the board a 5v constant or not so added test point for those.
added labeled the buttons and the programing header pinwise.
this the almost final pcb

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Anshuman Tripathy Anshuman Tripathy added to the journal ago

Polished the schematic and Routed the PCB

I properly labelled the sections of the Schematic and made it look cleaner.
Started out with the PCB completed routing and turns out finding the exact package of the component u have with u in kicad is a challenge.
Spent a considerable amount of time just looking at the PCB after complete routing to find the best and the most optimized route for a trace as possible. The pcb still needs some more work more of adding graphics and test points.
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Screenshot 2025-10-25 001547

Anshuman Tripathy Anshuman Tripathy added to the journal ago

completed the schematic

Began with sourcing the Symbol and Footprint for the DF mini mp3 player. Took a look at existing circuits using base atmega328p. Also decided to add a ADC pin to constantly monitor the battery voltage and show the playtime left on the oled.
visually the schematic needs some more polishing will do it later.

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Anshuman Tripathy Anshuman Tripathy added to the journal ago

Began with Reading Datasheets

Read the Data sheet of the DF robot mp3 player and Atmega328p. Also i will be using a 3.7 LiPo battery with it so i would need to step up the voltage to 5v for the module and Atmega328p IC run properly.
Thinking of using mt3608 step up ic.
Will also be adding a charging circuit to make it as portable as possible.
Thinking of adding a OLED display to it for seeing the status and track playing but no sure about it since i will need to design a enclosure incase i am adding one. Also adding it will cause a significant dip in the backup time . will decide later

https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf
https://wiki.dfrobot.com/dfplayer_mini_sku_dfr0299

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Anshuman Tripathy Anshuman Tripathy started MP3 Decoder ago