Read/Write registers over I2C for NTAG I²C plus Explorer Kit

[logansmall]

Hi there,

I'm attempting to read/write the memory in the NFC tag using an mbed microcontroller over I2C.

First, I am attempting to read the session registers from the tag using the given protocol from the specification (see: read.jpg)

Using mbed, I have written a function that will attempt to do this, it puts a start condition on the bus, then the I2C address (0xAA), and gets an acknowledgement from the tag. (see: code.jpg)

However, when I place the session register address (0xFE), I do not get an acknowledgement (nak). In fact, I have tried every possible MEMA from 0x00 to 0xFF, and all do not receive a response.

I cannot figure out what is wrong, is there something I have missed? Any help would be appreciated.

[logansmall · Accepted solution]

This ended up being an issue with how mbed implemented i2c writes, no worries.