Disclaimer: I am not a professional. This is project that needs some improvement but it works!

This project is DIY version of the Hoerbert MP3 player for kids. It is heavily inspired by Wooden Radio (MP3 Player for Children).

before the power led was added

• 12 dedicated buttons for mp3
• Next and Previous buttons for next or previous mp3
  • If you press on button 12, track012.mp3 will be played, and if you press next, track013.mp3 will be played
• After 4 minutes if nothing has been played turn off the radio

See .ino file

• 1 x LM2577 DC-DC VOLTAGE STEP-UP (BOOST) MODULE
• 1 x 1 A LITHIUM BATTERY CHARGING BOARD
• 14 x switchs
• 1 x 10k ohm variable resistor for volume
• 1 x Mini Pushbutton Power Switch with Reverse Voltage Protection, LV
• 1 x MP3 shield
• 1 x Arduino Uno
• 2 x Speakers that match adafruit mp3 shield - for example FRWS 5 - 4 Ohm
• 1 x 3,7 battery like a flat lipo or a 18650 battery with the battery holder
• PCB prototype boards

• 1 x 220ohm resistor
• 1 x led

• Add debounce mechanism

• Use less input when plugin pannel (for example https://chrigas.blogspot.com/2014/12/arduino-mp3-player-7-mehrere-knopfe.html)
  • https://arduinocompatible.blogspot.com/2011/03/3x4-analog-keyboard-for-microcontroller.html
  • https://twitter.com/flo_0_/status/679812590982291457
  • https://twitter.com/todo_arduino/status/673295091369443328
  • https://learn.sparkfun.com/tutorials/button-pad-hookup-guide/all
• Replay last song (see https://chrigas.blogspot.com/2015/04/arduino-mp3-player-17-sketch-3-der.html)
• Be able to keep the radio running even while recharging the battery. It is possible at the moment but this is not optimized. Instead you could use https://www.adafruit.com/product/1944 or https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=USB+lithium+lipo+battery+charger+3.7V+step+up%60module&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=5V+lipo+charging+usb+out+boost&LH_TitleDesc=0
• a web app to easily map mp3 to buttons
• find a way to display on, off, recharge status on the same led

• https://www.koelnerwasser.de/?p=617
• https://chrigas.blogspot.com/2014/10/arduino-mp3-player-1-auswahl-der.html