PN7150 AGC test kills the chip

[kena1]

In my project, I added test code to enable the AGC reporting on the PN7510. The chip reports the AGC value as expected. Then when I remove that code, the chip no longer works. The NFC chip is no longer visible on any I2C address.

I killed three prototypes this way.

Why would this happen? Can I recover from this?

Steps to reproduce:

Change the original CORE_SET_CONFIG command from:

{ 0x20, 0x02, 0x05, 0x01, 0x00, 0x02, 0x64, 0x00 }

to:

{ 0x20, 0x02, 0x09,  0x02,  0x00, 0x02, 0x64, 0x00, 0xa0,0x40,0x01,0x81 }

The extra command is from section 3.6.41 of AN11755 Rev 1.6

[IvanRuiz]

Hello,

May I ask which is the procedure you are following to remove the code from the board?

Thank you.

Best regards,

Ivan.

[kena1]

Ivan,

To revert the change, I just reload the original software on my microcontroller and write the first CORE_SET_CONFIG command.

Is there something more I need to do?

Ken

[IvanRuiz]

Hello,

May I ask if you are running this from Linux or Android?

Best regards,

Ivan.

[kena1]

It is programmed with custom firmware running on a Nordic Semiconductor nRF52840.