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Author Topic: Arduino library for WTV020-SD-16P audio module  (Read 76495 times)
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Narvik, Norway
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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 ? )
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Ny

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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.
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Narvik, Norway
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..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
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Ny

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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...
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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.
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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?

thanks
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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.
http://electronicsclub.info/vdivider.htm

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.
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Narvik, Norway
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resistor voltage devider wont do.  this circuit is not "constant current"
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Ny

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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.
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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:
http://apcmag.com/arduino-project-5-digital-audio-player.htm
and
http://www.hackerspace-ffm.de/wiki/index.php?title=SimpleSDAudio

bye

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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.
http://www.bajdi.com/lcsoft-vs1053-mp3-module/

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Examples can be found in your IDE.

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