SD card shield

Hi everyone. I’m using a SD Card shield with my arduino uno to be able to store my sensor readings over time. This is a Stackable SD Card shield (Link with a pinmap as attached here. Does this pinmap mean that I cannot use digital pins 0,1,4,11,12,13 and A4 and A5 for my other stuff like sensors? Thanks.

I don't think so but after looking at the link you mentioned it has mapped various pins for various boards to ensure compatibility so you may have lost some pins.

The standard SD card using SPI uses (from Arduino site):

_ * SD card attached to SPI bus as follows:_ _ ** MOSI - pin 11_ _ ** MISO - pin 12_ _ ** CLK - pin 13_ _ ** CS - pin 4_

That's all the pins you need to read/write from an SD card.

You say you have the card already? It would take you just few minutes to determine whether, for example, A4 and A5 were still available to you (by reading the analog signal with your finger touching the pin and then not). That might then give you a clue as to whether the other pins were still available.

Ralph_S_Bacon: I don't think so but after looking at the link you mentioned it has mapped various pins for various boards to ensure compatibility so you may have lost some pins.

The standard SD card using SPI uses (from Arduino site):

* SD card attached to SPI bus as follows: ** MOSI - pin 11 ** MISO - pin 12 ** CLK - pin 13 ** CS - pin 4

That's all the pins you need to read/write from an SD card.

You say you have the card already? It would take you just few minutes to determine whether, for example, A4 and A5 were still available to you (by reading the analog signal with your finger touching the pin and then not). That might then give you a clue as to whether the other pins were still available.

Thanks for your response. I did a test as you said. Without anything connected to pins, analogRead() for A0-A3 gives values in range 100-300 while A4 and A5 continuously read 1023. I also tried connecting each of pins to a 1.5V battery (ground to negative side of battery), and all of them read the correct value which corresponds to 1.5V. Does it mean all of analogue pins are available?

No it looks like A4 and A5 are being used as an I2C bus for some reason.

On the schematic http://wiki.iteadstudio.com/images/4/46/Sch_sd_shield_3.0.pdf A4 & A5 are pulled up in the upper right hand corner.