I was trying to connect the antenna board from the explorer kit to a 5v Arduino using a logic level converter. I connected the pins to the low side of the converter with it set to 3V and the high side unconnected, which left the low side pulled high to 3v. When I tried communicating with it via NFC it could read the tag but could no longer write to it, including configuration values. This continued even after disconnecting it.
I found in the documentation the RF_LOCKED and I2C_LOCKED flags and I was wondering if one of these might have been set accidentally in hooking it up. If so, is there an easy way to reset this flag via the i2c connection from an arduino library? I found this one GitHub - LieBtrau/arduino-ntag: Arduino library to interface with the NXP NTAG (NT3H1101 and NT3H120... however I'm not sure if it's able to access the IC specific flags or if it just treats it as a standard i2c sram/eeprom device.
If I've potentially damaged it electronically, is there a safe way of hooking this up that I didn't follow? Is there some beginner mistake I've made that I can avoid in the future?
At power-on, both flags are 0b, the status of these two indicators can be verified in Session register (table 14 of datasheet). Please make sure that the RF interface is not accessing the memory while trying to make an operation through I²C or vice versa.
Have a nice day.
Please verify that the memory is not locked to read-only e.g. with Dynamic Lock Bytes as mentioned in chapter 8.3.7 of datasheet. The Dynamic Lock Bytes are located in table 4 for the 1K version and table 5 for the 2K version from the NFC perspective.
Hope this helps.