# Using Catalex MP3 (YX5300) in Pushbutton Mode



## BobNJ (Jun 25, 2015)

I have experimented with this board and wanted to share my findings with this forum.

I recently purchased a few of these MP3 boards and found this forum while searching for information from other users. One thread had several posts about using this board with a microcontroller to command different functions. However, I was interested in using the Catalex board in a stand alone mode. ("We don't need no stink'n uP")

If you are familiar with this MP3 player then you already know that the instructions, in English, are limited to a 10 pg manual from Catalex which basically describes the command set needed to operate the board.

There is a also spec sheet for the YX5300 chip but it is in Chinese only. While looking through that spec I noticed on page 19 the use of switches and buttons which suggested to me that playback was not limited to 
just using serial commands. I would prefer to use this board without the need for an additional electronics to issue commands. Ideally, I wanted this board to begin playing the sound file then powered up and loop indefinitely.

I eventually translated most of the spec to English (with the help of Google Translate). Although the translation converts the Chinese symbols to their English equivalent, the words don't always make sense. For example the word "broadcast" is used instead of "play" and "retention" instead of "reserved". Also the syntax leaves much to be desired. Nevertheless, it's possible to make some sense out of this jumble of words.

I constructed a simple test circuit to explore stand alone operation (see photo). I wired slide switches from pins 9 and 12 to ground. I also connected pins 13,14,15 and 16 to pushbutton switches to ground.

These pins are not connected on the Catalex PC board. The chip has weak internal pullups so they are automatically set to a high state. Since the pins are not connected to any components on the board it is necessary to solder directly to the chip, where the pin spacing is 0.050". This can be accomplished with 30 gage wirewrap wire, a soldering iron with a needle tip, a magnifier and a steady hand.

Here are my test results thus far:

MODE 1 - Pins 9 & 12 both HI (default): Pressing & releasing IO1 (pin 13) starts 1st sound file, pressing it again restarts the same sound file from the beginning. Goes back to idle state arter sound file has completed. Pressing IO2 starts the 2nd sound file, IO3 starts the 3rd sound file and IO4 starts the 4th sound file. Pressing any IO button while a sound file is playing immediately stops that file and starts the file associated with that button

MODE 2 - Pin 9 LO, Pin 12 HI: Press & hold IO1 starts 1st sound file, releasing it stops playback. Pressing it again starts sound file from the beginning. The sound file will loop as long as the button is pressed. Pressing IO2 plays 2nd file, etc

MODE 3 - Pin 9 HI, Pin 12 LO: Pressing & releasing IO1 (pin 13) starts 1st sound file, pressing it again has no effect & pressing any of the other IO buttons has no effect on the sound file currently playing. The sound file plays through completion and then waits for the next trigger.

MODE 4 - Pin 9 LO, Pin 12 LO: Pressing & releasing IO1 (pin 13) starts 1st sound file, pressing it again immediately starts playback of the next sound file. Pressing IO2 stops the current playback and begins the previous sound file. IO3 operates as a Play/Pause button. IO4 stops playback.

So for my project I wanted continuous looping and it appeared that Mode 2 was the way to go. I had hoped that I could simply wire IO1 to GND so that it would start playback when powerd up. That did not happen. It is necessary to wait for a ready condition before a trigger is accepted.

However, I did determine that Mode 4 would accept a grounded IO1 line and immediately begin playback when powered. Since I had multiple files on the SD card, it sequenced through all of the files before it looped back to the first one.

The sound files I used for testing were MP3's (stereo, 44KHz, 224kbps), relatively short about 10 seconds, with file sizes around 100KB. All the files were in the root directory and were named test001.mp3, etc. I also tried using WAV file and they played OK as well.

Note that the default volume setting on power-up is set to MAX.

Hope this forum finds this information of some use.


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## mikkojay (Sep 15, 2014)

That's a great bunch of info- thanks for sharing. I cannot believe I went 3 weeks without seeing this! Man, that is some super teeny fine soldering detail work!
Thanks, Mike


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## BillyVanpire (Apr 22, 2015)

i also missed this, i was curious if these would play stand-alone myself.

nice work BobNJ


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## BobNJ (Jun 25, 2015)

Here's my 1st attempt to modify the Catalex MP3 board so that it will automatically play and loop sound files on powerup.

I used a 0.030 diam bit to drill some very small holes adjacent to the # 9, 12 & 13 leads (see photo). I'm drilling into the ground planes, both top & bottom. I then inserted a 30 gauge wirewrap wire through the hole, bent it over and soldered it to the pins on the YX5300. I soldered the wires coming out the bottom side to the ground plane.

Drilling the holes is a bit tricky and requires suitable magnification to get them lined up.

Works great!


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