RFD22130 SD Card reader with Uno Wifi R2

I have a Uno Wifi R2 hooked to an I2C 20x4 display that is working using the I2C LCD example.

Now trying to use an old RFD22130 SD card reader that I have laying here using the SD example and it never gets pass the "initialization failed!"

If I move this over to my old Mega2560, and use SS PIN 53, it works.

At first I tried pins 4 / 11/12/13 ... then pin 4 to 10 ...

Then read to use ICSP header pins.. still no go...

I know I am goofing something up here... as ive had some hard time finding Dedicated Wifi R2
pin outs and documentations as it IS different then the R3 and older UNO boards...

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From the SD library documentation:
https://www.arduino.cc/en/Reference/SD

another pin must be used to select the SD card. This can be the hardware SS pin - pin 10 (on most Arduino boards) or pin 53 (on the Mega) - or another pin specified in the call to SD.begin().

As you have learned, despite the name, the Uno WiFi Rev2 is quite different from the standard Uno. On this board, the SS pin is not actually broken out to a pin header, so you can’t use the default SS pin for the SD CS. Fortunately the SD library allows you to set any CS pin you like via SD.begin():
https://www.arduino.cc/en/Reference/SDbegin

pert:
From the SD library documentation:
https://www.arduino.cc/en/Reference/SDAs you have learned, despite the name, the Uno WiFi Rev2 is quite different from the standard Uno. On this board, the SS pin is not actually broken out to a pin header, so you can't use the default SS pin for the SD CS. Fortunately the SD library allows you to set any CS pin you like via SD.begin():
Arduino - SDbegin

I did find that info and tried another pin but didn't seem to fire off any better results. Probably the one pin
that is a big no no to use or something :slight_smile:

I will attempt again tonight when I am home.

I primarily use NANO's for my little projects... The Mega is well.. Mega... way to big. And the Uno Wifi R2 fit the bill.... just gotta learn the layout of the land on this one.

I moved it from the 3.3v to the 5v pin and all is good now on this board...

I had 12v power supply plugged in, so should have had plenty of power.

At least all is good now and it works.

I'm glad to hear it's working now. Enjoy having fun with your Uno WiFi Rev2!