Hello,
I have the SparkFun VS1011 breakout board and I’m trying to wire it to my Arduino Uno. THe breakout board has onboard 3.3v regulators so I plug the 5v from the Arduino right into the +Vin of the VS1011 board. So now it has power 
That, I think, I have a handle on. It doesn’t look like the input SPI pins are 5v adjusted though, so I run those through a 74LV245 which is powered by a separate 3.3v regulator I set up. It all seems OK. I can read and write SCI registers and initiate sine tests. At least most of the time 
I mined the VS1053 shield Arduino code for an example and ran the embedded “Hello World” mp3 into the board and I get weird results. It seems like it wants to play it but it can be garbled or it drops out all together. I find that if I ground one of the Arduino input pins the MP# sort of plays OK with some intermittent glitches. If I don’t ground an input pin the MP3 plays for a short bit then drops out. This leads me to think there is a power issue of some sort that interferes with the SPI or the VS1011 chip itself. But why would grounding a pin make the system more stable?
Also, running the SPI with SPI_CLOCK_DIV4 seems like the correct setting for the SPI but it really doesn’t work well. I have to put it at SPI_CLOCK_DIV2 to get it to play. And that seems too fast for what the datasheet says The VS1053 code seems to use SPI_CLOCK_DIV4.
has anyone had any luck wiring one of these VS1011 breakout boards to an Arduino?
Thanks,
Bob