# Possible replacement for Tenda MP3 module



## tstraub (Feb 26, 2012)

A lot of people here use the MDFly MOL-AU5121 MP3 module for DIY designs. It is a great little MP3 player for the price. The only problem with it is that MDfly can't seem to keep them in stock. I was just looking at MDfly and of course its out of stock right now. But I noticed in the similar products they now offer MOL-AU5120 I took a quick look at the datasheet and it appears to be a pin to pin match for the MOL-AU5121 The only difference I see is that it is smaller in size and uses a MicroSD card rather than a full sized SD card. Anyway I have a couple on the way here for testing.

Tyler


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## halstaff (Nov 18, 2009)

I'm interested in hearing how these work out. They do have a wider operating power requirement range - 3.6V to 12V which is nice instead of 6V to 12V.


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## Zombie-F (Apr 12, 2004)

Yeah, let us know how it works. I loved the other one because you didn't need to use any caps and resistors to create a line out signal for amplified speakers. Hopefully, this is the case with this one too.


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## JeffHaas (Sep 7, 2010)

Zoom in on the image...that's a different Tenda module!

Specifically, this one:
http://www.tendaelectronics.com/index.php/wareshow/tenda/1/en/688,427/427.html

Looks like it uses a smaller memory card (Micro SD) than the other one.


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## Dead Things (Apr 4, 2009)

Look forward to your experiments, Tyler. I need to order a couple of boards.


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## mkozik1 (Sep 6, 2010)

I did the same thing Tyler and purchased one as well. It is here on the bench but I have not had the time to go through it yet - Ugh!! Will do over the weekend and report my findings as well.


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## halstaff (Nov 18, 2009)

I ordered 3 of the other ones so added in one of these to my cart as well. Looking forward to checking it out.


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## mkozik1 (Sep 6, 2010)

OK - Have been playing with this thing and cannot seem to get it to play any other sond but the last one on the card. They are all numbered 001.mp3 - 004.mp3. I am using an arduino to send the commands and each time I send the command, 004.mp3 begins to play. Knowing that it starts from the beginning leads me to believe my comm is good (if I remove the tx/rx wires the song continues to play through, put them back and it starts from the beginning). I have tried sending just 01 as well as 001.

Not having played with any others like this, I am now lost!! What am I doing wrong?


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## halstaff (Nov 18, 2009)

Do you have your SD card formatted to Fat32? 
I don't use multiple files but I remember that was suggested when I started using these. Now I just do it as a matter of course.


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## mkozik1 (Sep 6, 2010)

Yes, FAT32


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## ScaryLane (Jun 3, 2013)

mkozik1 said:


> OK - Have been playing with this thing and cannot seem to get it to play any other sond but the last one on the card. They are all numbered 001.mp3 - 004.mp3. I am using an arduino to send the commands and each time I send the command, 004.mp3 begins to play. Knowing that it starts from the beginning leads me to believe my comm is good (if I remove the tx/rx wires the song continues to play through, put them back and it starts from the beginning). I have tried sending just 01 as well as 001.


I've tried searching the web for the PDF of the TDB381 with no luck, the PDF on the TDB380 shows you should name the the files A001.mp3, A002.mp3... I've always used the "A" at the start of the files and it worked for me.

The other thing the manual talks about the order the files should be written to the SD card. Put the folders on the SD card first, followed by the MP3 files in order.

Sometimes these modules have very simple file I/O code and don't even look at the file names all that much.

A more complete pdf on the TDB380 can be found at:
http://www.echelleinconnue.net/outils/mobio/composants/TDB380_datasheet_V2_%28Tenda_Electronics%29.pdf


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## ScaryLane (Jun 3, 2013)

tstraub said:


> I took a quick look at the datasheet and it appears to be a pin to pin match for the MOL-AU5121 The only difference I see is that it is smaller in size and uses a MicroSD card rather than a full sized SD card.


While I can't find the PDF on the MOL-AU5120 (TDB381), the real differences beyond you already pointed out are ...

The straight mounting pins (not 90 degree bend) and using 3.3 volt logic.

In the case of the straight pins, the module will lay flat on the board. While this takes more board space if not at the edge of the circuit board, it also keeps it low profile in design.

The MOL-AU5121 (TDB380) used a 5 Volt regulator to drive most of the circuit and why 6 Volt or greater was needed to run it. (The on board voltage regulator needs 1 to 2 extra to run it.) It looks like the MOL-AU5120 (TDB381) uses only 3.3 Volt circuity and only needs 3.7 for the on board voltage regulator to work and why it can run off of a 5 Volt power supply.

Since I can not find the full PDF manual on the TDB381 board, I'm wonder if the RX/TX are still comparable with 5 volt logic since the module is running on 3.3 volt Logic. At this point, the only way to know is to hook up a Picaxe and see if it works reliably.


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## JeffHaas (Sep 7, 2010)

Don't forget you can put the files on the SD card and then use DriveSort to fix the FAT so they're read in the right order.

http://www.anerty.net/software/file/DriveSort.php


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## tstraub (Feb 26, 2012)

Well mine came in the mail today. Here are my findings so far.

It does seem to be a drop in replacement for the TDB380. I put it in one of my 4 channel learning prop controllers and one of Steve's Frankenstein controllers. Both controllers preformed as expected.

It came to me with a 90 degree SIP header just like the TDB380 so it stands up on the PCB same as before.

It seems to be 5 volt tolerant on the serial input pin. Its been running for about an hour with no problems.

Audio output is right on par with the TDB380. I can't hear any difference from one to the other.

The only complaint I have is it inserting the microSD card can be a bit more difficult than the one with the full sized SD card. The micro SD card does not simply slide in. You have to open a door to insert the MicroSD card. There is a slight interference when opening the door while the module is inserted in my prop controller. See attached picture for more details on the interference. The door does open far enough to get at the card but it's probably easier to remove the module if you need access the the SD card.


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## halstaff (Nov 18, 2009)

Good to hear. I should have mine on Friday.


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## Zombie-F (Apr 12, 2004)

Very good to hear. I still have a few of the other ones, but it's nice to know there is an available unit that is a drop-in replacement.


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## HomeyDaClown (Oct 3, 2009)

Looks pretty good. You could always use a stackable header
to raise the board a bit and give clearance for the Micro-SD card holder.
It would allow easy removal of the board.

https://www.sparkfun.com/search/results?term=Stackable+Header


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## mkozik1 (Sep 6, 2010)

So Tyler,

I am stuck and am in need of some help please Sir. What commands are you sending your MP3 player to get it to play specific songs? Mine just keeps playing the same song over and over. I have tried 001, 01, A001, A01 and every other combination of the 01 but each time the command is sent to the unit, the same song starts over again. I know it is getting something because if I disconnect the TX line, the song continues to play through. When I connect it and watch the commands go over on the SerialMonitor, then each time one goes, the song starts over.

Thanks in advance for your help with this.


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## JeffHaas (Sep 7, 2010)

Mark,

What microprocessor are you using? When the Tenda module came out, I read about it on the Picaxe forums, and ported the code so it works with Picaxe, Basic Stamp, and Arduino. Let me know and I can post something.

Jeff


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## Zombie-F (Apr 12, 2004)

Mark, could you post your code and let us know what microprocessor you're using?


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## HomeyDaClown (Oct 3, 2009)

mkozik1 said:


> So Tyler,
> 
> I am stuck and am in need of some help please Sir. What commands are you sending your MP3 player to get it to play specific songs? Mine just keeps playing the same song over and over. I have tried 001, 01, A001, A01 and every other combination of the 01 but each time the command is sent to the unit, the same song starts over again. I know it is getting something because if I disconnect the TX line, the song continues to play through. When I connect it and watch the commands go over on the SerialMonitor, then each time one goes, the song starts over.
> 
> Thanks in advance for your help with this.


Only thing I can think of without seeing your code is at 4800 baud. Is your serial set to 4800 N81? I'd insert a brief delay or pause just after calling a file to play before executing the next line of code. This will give the buffer a chance to load the serial command and also give a chance for the file to be found.

There are few V2.0 serial functions that are no longer valid in the latest firmware.

The new Model No.:TDB380 Datasheet V2.1 pdf can be found here: 
http://www.google.com/url?sa=t&rct=...DXRi47hnSnPZeAw&bvm=bv.52164340,d.aWM&cad=rja


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## mkozik1 (Sep 6, 2010)

Hi guys,

I appreciate your help with this. I am using an Arduino Nano with very simple code based on the information from the PDF on the MP3 player. Just as a test, I have the code moving through 4 different songs just to confirm the code;


```
void setup()
{
  Serial.begin(4800);
 }

void loop()
{
 Serial.println("001"); 
 delay(10000);
 Serial.println("002");
 delay(10000);
 Serial.println("003");
 delay(10000);
 Serial.println("004");
 delay(10000);
 Serial.println("Done");
}
```
I look forward to your expertise.


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## JeffHaas (Sep 7, 2010)

Mark,

Check this thread out from 2010, I provide sample code:
http://www.hauntforum.com/showthread.php?t=22800&page=9

Key thing: Use BYTE format to address the Tenda boards with an Arduino. Details in the thread.


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## HomeyDaClown (Oct 3, 2009)

mkozik1 said:


> Hi guys,
> 
> I appreciate your help with this. I am using an Arduino Nano with very simple code based on the information from the PDF on the MP3 player. Just as a test, I have the code moving through 4 different songs just to confirm the code;
> 
> ...


To send the required hex values (01,02,03,04....)

use: 
Serial.print(0x01, HEX);

or just

Serial.write(0x01);

print and println require the HEX parameter in order to send HEX values.

The BYTE parameter is no longer used in IDE 1.0 and above.


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## mkozik1 (Sep 6, 2010)

THANK YOU for your help with this. Unfortunately, I am not at home this week to try this but will this weekend and post my findings.

Again, I appreciate your time and efforts to help me.


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## imax (May 22, 2006)

Just a quick note about the file naming here... (and it took me forever to figure this out so maybe I can save you some time...)

THE FILENAME IS NEVER READ BY THE MP3 UNIT.

Basically what the mp3 unit is doing is reading the FAT table in order. The first file found gets slot 1, the next slot 2, etc.

When I load up a card for this module, I always do the same thing:

1) Format the card. FAT only. FAT32 should be compatible, but it really depends how they implemented the code that reads the table. Play it safe.
2) Copy the files over one by one. Don't select multiple files and hope they end up being written in the right order. That's what they are trying to accomplish with the whole A001.mp3, A002.mp3, A003.mp3 naming schemes. It will just get you into trouble. Copy and paste one by one, in the order that you need.

I hope this helps someone. I also have the full datasheet (not the neutered one from MD Fly) if anyone needs it.


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## Zombie-F (Apr 12, 2004)

imax said:


> Just a quick note about the file naming here... (and it took me forever to figure this out so maybe I can save you some time...)
> 
> THE FILENAME IS NEVER READ BY THE MP3 UNIT.
> 
> ...


Oh man! I had totally forgotten about this detail. For some of my projects, I only had one file on the SD card, but for my monster in the box, I had four files and had to go through this to get the files to play as needed.


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## mkozik1 (Sep 6, 2010)

You guys ROCk - Now I can't wait to get home to try this out!! Again, thanks for all the help.


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## JeffHaas (Sep 7, 2010)

I've also had luck with DriveSort...I named the files like A001.mp3, A002.mp3, A003.mp3, etc. and copied them to the SD card. Then I used DriveSort to sort the FAT so that the files were "in order" for the Tenda module.

And Homey - thanks for the catch on the update to the Arduino IDE.


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