Arduino library for WTV020-SD-16P audio module

Hello guys,

a friend of mine asked me if I can make something play very fast, a few times / second. A very short sound track to be played a few times / second, he wanted to be able to modify the repeat frequency. I don't have yet an audio module to test out the library, and I want to ask you

Is there any lag after the command to play a track ? can a very short track be played multiple times in a second ?

Thank you

Trying with my module with no luck.. for two days now!...

Read all the thread and today i tested four SDs with ethernet shield.. the two of them (2GB) worked fine... the other two (4GB, 1GB) are not working...

The one of the two (2GB) is Kingston . Tried various formats but no luck... the unit is complete silent.. Only the LED after some seconds stay lit...

I am just wondering.. is there any other module maybe more "serious" out there to produce sound with arduino and especially with no gaps at loops?

Thanks in advance!

skoubri: ... especially with no gaps at loops? ...

Please can you elaborate, this is what I'm curious too, but so far I can;t test as I don;t have any siund module .. is there any gap when looping a sound (even if the sound is very short) ?

I have had problems with theese chips. (still have) I came over an idea (cant remember where) that 3,3V may be just to low to make this work. A cellphone battery (3.6V) as powersupply had make it work as a standalone unit.

knut_ny: I have had problems with theese chips. (still have) I came over an idea (cant remember where) that 3,3V may be just to low to make this work. A cellphone battery (3.6V) as powersupply had make it work as a standalone unit.

If the 3.3V is low, check the 5V! You may have been dragging too much current through the board for its own good. Check the power requirements of the module at full volume. If it needs more than 100mA then you probably should use external power, Arduino total should not exceed 200mA and best not to draw that much Through The Board.

Yesterday arrived my second module as i have ordered some of them.. Identical to the first same type IC , etc...

It PLAYED just out of the box! Have the same behavior when plays(LED) so i think that the first one has something with audio output.. seems to play but not sound on the speaker or audio out pin.

But i am still looking for a "gapless" solution or the ability to have a long sound file and jumps into parts of it with no or very short delay...

Hi guys I'm having problems with my wtv020 sound module. It seems that the LED blinks a few times, then stop blinking. But there is no output sound can be detected from the speakers. I'm using a two types of SD cards which is SanDisk 2GB MicroSD and SD-C02G microSD/T-Flash Card Toshiba. I've copied the AD4 files form circuitstoday into the SD cards, so i assume there is no problem with the files. Your coorperation is truly appreaciated =D

Hardware Question,

how can i activate the 5-File keymode ?

hi, i bought 1 module WTV020-SD Micro SD Card mp3 but i have few problem to make it work, i real all the posts and i have not found solution ...

i use this tutorial : , i use the 3.3v power of the arduino and gnd to make it work...

First i use no name micro sd card 128mo and i try with a sandisk 2gb but the led don't blink! do you know why?

i have a question, if the sd card is not compatible, the led blink or not with this schematic?

thanks for help

I've go two of theese 'nonworking' modules. (crap) Found one answer that made a difference. He increased voltage to 3.4..3.5V That can be done feeding 5V through a copule of diodes (or a red LED ? )

knut_ny: I've go two of theese 'nonworking' modules. (crap) Found one answer that made a difference. He increased voltage to 3.4..3.5V That can be done feeding 5V through a copule of diodes (or a red LED ? )

You can make a voltage divider and fine-tune the output voltage very close to what you want.

..I guess the sound module needs changing differents .. which means a resistive voltage divider is out of Q. Better with seriel diodes.. Or a near empty cellphone battery

today i’ll try with a 3,6v cellphone battery…

but i read many tutorial where 3,3v is good to make it work…i don’t know why…

If the circuit pulls more current than the source wants to give, you will get a voltage drop. Even too many leds can take Arduino 5V down to 4.5V. At 16 MHz, any lower and it may get unstable. So what happens when the sound chip and SD are both at full pull? A few 10th's of a volt may help.

I'm pretty sure that I can feed SD 3.7V and likely most other 3.3V devices as well. FWIW, Arduino can take 5.5V too, but you probably shouldn't put 6V on VIN.

thanks for your help!

it's possible to make a voltage divider with 2 resistors and take ouput 5v of arduino?

i need 3,6v or 3,5v?


Resistors usually come in standard values, and I for one don't have all of those. But they can be put together in serial and/or parallel to make almost any value.

Here is a link showing voltage divider and formula. That's a really good site, you might bookmark it.

If R1 is 2000 ohms (2 1K's in series for me) and R2 is 4700 ohms the Vo would be 3.5V.

Notice that Voutput = Vsource x ( R2 / ( R1 + R2 )) ( R2 / ( R1 + R2 )) gives the fraction of source voltage that output voltage will be independent of source.

I used 3 x 4.7K resistors to make a 1/3 drop by putting 2 in series to make R2 and the other to be R1. My output voltage is 2/3 which for 5V is 3.3V. To get 3.5 I varied the ratio so that less goes straight to ground.

My output current runs through the 4.7K resistor so it will be less than if no divider is present but I don't need much current, it is for voltage-leveling a serial pin on a 3.3V chip to a 5V Arduino. I used 4.7K's so that less current would flow to ground than with lesser ohms. That may be more resistance than you want, the 2K-4.7K example above is half as much. Still, you may need to play around to get just what you want/need.

resistor voltage devider wont do. this circuit is not "constant current"

Is there a maximum current specified for the WTV020-SD-16P? If not then pick resistors that let at least the most current required by the module.

My UNO is supplied 500 mA at 5V by USB but it doesn't use 500 mA. It is recommended to not draw more than 200 mA through the board and the UNO itself uses little more.

So is constant current required for this module? The Elec doc says 3.3V and nothing about limiting current.

Voltage divider does impede current because output current goes through a resistor. That is why you have to pick the resistors to allow enough current through to run your app.

hi and thanks for your help

today i test with 5v arduino and 2 diodes 1n4001 in series but the led don't blink... i don't use a speaker but a pair of earphone, i test it with no name sd card 128mo and a sandisk 2gb

i add led after the diodes and i connect it to VDD to see if the module receive voltage and the led works, after i add led between GND of module and arduino gnd and the led works, i don't understand.

This module really sucks...tomorrow i receive a new module if it don't work i stop with it...

i saw an other possibility to play mp3 or wav with a cheap sd card module that i have, if you are interested: and


I have a VS1000 that works but for OGG files. The MP3 to OGG converter is available at the VLSI-Solutions home site. The module itself has onboard flash and a micro-SD slot and can be run through simple serial commands. To get just 1 or 2 direct from the company to USA, there's a courier delivery fee that doubles the price so here you would want to find a supplier though I dunno who.

I have some Chinese modules that to get playing MP3 requires soldering 2 SMD pins together which I'm not good enough to even try.