MP3 Module
without an Arduino

(or other microcontroller)
d. bodnar   revised3-02-2015 & 8-12-2018

The unit shown here is the same as those in the article but it uses a custom circuit board that I designed and had fabricated.

The MP3 player that I used in the
Talking Defector Project is frequently used with a microcontroller like an Arduino.  It can, however, be used for many applications by just adding some buttons and resistors. 
Three of the variations on this method of operation are shown here.  In addition to the MP3 module each has a 7805 voltage regulator that supplies 5 volts to the player.  There are also sockets with 2 and 3 pins.  The 2 pin socket connects to pins 7 and 9 and can be used to drive a speaker directly.  The 3 pin socket connects to ground (center pin) and to pins 4 and 5 and is used to drive an external powered speaker.  The 3 pin socket is stereo while the 2 pin is mono.

The unit on the right and the one in the center are wired as shown in this diagram.  The center unit only uses buttons connected to pins 9 and 11.

The unit on the left has 10 pairs of pins that are connected to resistors as shown in this diagram.  I only wired one set of switch pins and one set of resistors and used another jumper to select if the pins go to pin 12 or 13 on the MP3 module.

This drawing may be a bit clearer.