Your grovepi solution is very interesting for easy implementation of actuators and sensors. However, I can’t get the NFC tag to work.
I own a raspberry 3 model B version 1.2, with Rasbian Jessie OS and a grovepi+ V3.0.
I want to use the NFC tag (https://www.seeedstudio.com/Grove-NFC-Tag.html). The program you give does not work with this NFC model. I get the same values whatever the card I use.
The NfcV-reader for android doesn’t give me the same results.
However It seems that the I2C address is the right one (0x53).
I don’t understand what’s going on. Can you help me?