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hpr3809 :: The Abominable Post Apocalyptic Podcast Player

Build a Three Dollar MP3 player in One Hour

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Hosted by Mechatroniac on 2023-03-09 is flagged as Explicit and is released under a CC-BY-SA license.
robotics, mp3, GPD2846A, GPD2846, DIY, arduino .
Listen in ogg, spx, or mp3 format. | Comments (4).

Arduino and related devices.

In this series various contributors talk about how to use and program Arduino single-board microcontrollers and related devices.
See the Wikipedia article for details of the range of devices.

Notes: Forgot to mention that I hot glued the top lid (original lid for the 'speaker box'), on top of the boards. I had used the device with the top uncovered for a month because I hoped I would find a better choice but after getting tired of the wires detaching and worrying about the sdcard slot getting wrecked I decided to commit to glueing the lid on.

The boards are very robust, I dropped them in the snow a few times. They would stop working but after drying off would function.

I didn't find the datasheet with the resistance values for other values until after I glued the lid so will have to open it up again or get into one of the switch lines and do resistor combinations... now that I know more I think I should be able to control the mp3 player with one analog output pin from the arduino for all the functions, since it seems the pin 8 that all the switch resistors lead to detects voltage levels from the voltage divider created when one of the switches goes to ground.

The robot is using 4 lines right now for mp3 control. Would be cool if I could free up 3 more but I don't remember if any of them are occupying an analogue slot.

No power button! None needed. Pause and unpause via momentary switch. The charger board can charge from micro usb or usb-c and will protect your 18650 cell from running flat and damaging itself.

Check out my robots:

Post Apocalyptic Robotics Database Entry:
H Hybrid: Denotes some prepurchased or hard to find components
H Human use: For use by biological humans

Tools and supplies

  • multimeter - not strictly required but highly recommended
  • Soldering iron
  • solder(thinner solder wire works better for electronics)
  • wire stripper
  • hot glue gun
  • electric or duct tape
  • side cutters/cutting pliers/aircraft snips


Find or Buy:

  • short lengths of wire

  • 4 ohm speaker (can be found in old tvs)

  • momentary switches(3) - can be found in vcrs, tvs, dvd players...

  • 18650 cell

  • 3.5g weed jar or similar + lid

  • larger lid

You should consider getting an arduino or a kit

Picture 1
Picture 1
Click the thumbnail to see the full-sized image

Picture 2
Picture 2
Click the thumbnail to see the full-sized image

Picture 3
Picture 3
Click the thumbnail to see the full-sized image

Picture 4
Picture 4
Click the thumbnail to see the full-sized image


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Comment #1 posted on 2023-03-09 03:22:39 by Some Guy on The Internet

The normiees wouldn’t like it.

Do you leave home with this device? If so, are you arrested for having that device? I imagined myself being arrested if I walked around with something like this. Thank you for providing the show.
Comment #2 posted on 2023-03-09 13:59:55 by Mechatroniac


pic 1 shows the slit in the lid where the sdcard resides. Sdcard and slot are protected from being bumped by the strategically placed, glued lid pic 2 shows charging, microusb cord is coming in from the bottom, LED on charging board illuminates brightly pic 3 shows both boards glued to bottom lid, with the top lid off
Comment #3 posted on 2023-03-09 18:04:01 by norrist

Premium HPR content

This is a very cool project. More like this please.
Comment #4 posted on 2023-03-10 20:22:36 by Mechatroniac


SGOTI - check your local regulations :-)

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