NFC Shield + Arduino Mega ADK = Not working?

I want to make NFC reader as an Android accessory.

I bought NFC Shield and Arduino Mega ADK.
Topping NFC Shield on Arduino Mega ADK is great.

When I download Android accessory sketch, it is working well.
When I read NFC tag, it is working well.

When I mix two sketches, I can see PN53x not found.

It seems to be that I need to control SPI well but I don’t know it well.
Or maybe there is initialization sequence for it.

Does anybody experience on this?

Hi ,
Maybe is the issue that NFC and ADK used the same SPI enable port(D10) .You can try to change the SPI enable port of NFC Shile.

#define SS 10

change to

#define SS 9

And then disconnected D10 to SDK , use a a wire jump D10 to D9.