Chinese rubbish.... or is it?

[Yveaux]

Today this nice MP3 player board with microSD card reader arrived in the mail:

I bought it from my good friend Ali and planned on creating a MySensor'ed doorbell node.
It conforms to the default Arduino Uno pin layout, as you can see.
Size doesn't really matter so I figured to stick it on a Uno to have the whole thing up and running in no time.

Some of the pins of the VS1053 appeared to be soldered together on my board, so I started surfing the net, looking for some schematics of the board... None found (of course...)
It seems very similar to Sparkfun's MP3 player shield, except for one missing item: a level shifter.
This got me thinking... OK, maybe the VS1053 and SD card IO's are 5V tolerant... No, that's not the case.
Maybe they used some voltage dividers to go from the 5V UNO signals to the 3V3 signals required by the VS1053 and SD card. Took the multimeter. No, directly connected.

So this board directly routes 5V signals to 3V3 tolerant chips...
Who the hell designs, and then dares to sell an Arduino UNO shield that's incompatible to an Arduino UNO???

The net shows some supposedly succesful attempts of using this board, directly connected to an Arduino Uno.
Were these guys just lucky they didn't fry the whole board? Or am I missing something?

I didn't dare connecting it to an UNO yet. I think I'll start with a 3V3 Pro Mini first Update At least it works flawless at 3V3 with Sparkfun's library

What do you think? Or maybe you encountered such fiascos yourself?

[hek]

Amateurs...

[FotoFieber]

@Yveaux
Do you have developed a mysensors sketch?

Yesterday I ordererd a DFPlayer board http://www.ebay.com/itm/271726316962 and plan to use it for announcements like

• room kitchen, please close window
• bedroom, please open windows, bad air quality
• car arrived (garage)
• ....

[sincze]

@Yveaux : At least you were able to figure it out. I would simply have connected the thing and start sending smoke signals.

[Yveaux]

@FotoFieber yes, I did get it to work with a 3.3v pro mini. But the module you're referring to is not based on the vs1053 mp3 decoder chip, so it has to be controlled differently...

[FotoFieber]

@Yveaux said:

@FotoFieber yes, I did get it to work with a 3.3v pro mini. But the module you're referring to is not based on the vs1053 mp3 decoder chip, so it has to be controlled differently...

Yes, the driver logic is different. But I would be interested, what message types you used. AFAIK there are no matching types defined by the api...