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Topic: New library for PWM playback from SD cards: SimpleSDAudio (Read 45 times) previous topic - next topic

Tuttut

Another thing: I don't like the solutions from sparkfun levelshifter site because most of them are pretty slow. Better use a voltage divider with two resistors per line as described in SimpleSDAudio.h. This is proven to work even at fast SPI speeds as required for my lib.

xl97

if you really want to test this..

I suggest grabbing a few resistors.. and making a voltage divider, so that your LOGIC level will work correctly..

I have read about the voltage dividers being 'slow' (or too slow even).. but I have tried and tested this myself.. and it works fine for me & initial testing.

IMHO (again Im a noob!  <--- disclaimer!) .. you have +5v Arduino/board..  (period)

In order for the SD card to 'work'.. you need an Arduino that RUNS @ +3.3v logic...
or
A voltage divider between Arduino & SD card.


meowth08

#137
Feb 22, 2013, 09:43 pm Last Edit: Feb 22, 2013, 09:44 pm by meowth08 Reason: 1
+5V------4.7k-----(x)-----10k------gnd

this will be for mosi, sck, and cs

MISO does not need a level shifter.

is this already correct?


xl97

Follow this diagram (worked for me)



not sure the 4.7k / 10k will work..but other diagrams seem to elude to it works fine:




make 100% sure that your +3.3v output pin on the Arduino is REALLY outputting only +3.3v

Tuttut

#139
Feb 22, 2013, 10:09 pm Last Edit: Feb 22, 2013, 10:10 pm by Tuttut Reason: 1
Hi,
I think both voltage dividers will work, if you don't have those 1.8k and 3.3k resistors also the 10k/4k7 solution should do it. BUT: Do you really have a CrApDuInO+gizDuino+ (the plus version)? In such a case please tell me exactly how the menu item under "Board" inside Arduino-IDE is called that you use. I can help you to get it running even on such strange Arduino board but it will need some "special handling".

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