Need help with NFC shield

[kevinljxljx]

Hi guys. So I just got a Adafruit NFC shield today. I downloaded the library and burned the example program to my arduino Mega 1280. But it didn't work......... I connected VCC and GND (of course...), SDA and SCL to 20 and 21 port, analog 4,5 to analog 4,5 on Arduino board, Digital 2 to PWM 2 on Arduino board and RSt to RST. However, when I try to run the program, the Serial Monitor show "Hello, Didn't find PN53X board." Did I use the wrong library and wrong program or what? Can someone helps me out? Thanks!

[adafruit_support_bill]

SDA and SCL to 20 and 21 port, analog 4,5 to analog 4,5 on Arduino board

Analog 4,5 are SDA and SCL on an UNO. On the Mega, you should only connect SDA, SCL to pins 20, 21.

[kevinljxljx]

Thanks, I finally figure out that I connect the wrong port.
I have some more questions that I am trying to write something to my card, but the example programs seems doesn't like to work. Can you help me out?
Finally, I am confused about NDEF cards and mifare classic cards. What's the difference between these two types of card?
Thanks!

[adafruit_support_bill]

the example programs seems doesn't like to work. Can you help me out?

Can you be more specific about the problem?

Finally, I am confused about NDEF cards and mifare classic cards. What's the difference between these two types of card?

NDEF support is limited at this point. There are a few threads on the forum related to this topic:

viewtopic.php?f=31&t=35489&p=175664
viewtopic.php?f=31&t=33836&p=174406&hilit=ndef#p167479

The detailed description of the differences is here:
http://www.nxp.com/documents/applicatio ... AN1304.pdf

[kevinljxljx]

yeah... so I was trying to use the example program to write my email address to the card, but when I try to upload the program, the software tells me error, like what the screenshot shows.
BTW, do you have a list of what command I can use with the library? Thanks!

[adafruit_support_bill]

There are three definitions of "url" in that example. You can only use one of the three, you have to comment out the other two.

[kevinljxljx]

ok I get it now...I can only use one out of three....
and how about this ? I don't know where the error come from....

[adafruit_support_bill]

Move the array assignment up to the declaration line for data.

Code: Select all

uint8_t data[16] = {'a', 'd', 'a',     ... etc...