Flashing the NHS3152 via NFC:

[CyrilBZH]

Hello,

I'm using the NHS3152 demo board.

Thanks to these forums I've been able to solve several issues I had programming this chip.

So now I can program, power and exchange data with  the NHS3152 through the NFC. 

I'm now in the position to design fully my application with my own PCB.

The pcb for that will be tiny (about 11 mm in diameter) and only 2-side possible, so I won't have rooms for many components.

I have few questions:

1) I noticed that once flashed via NFC, that I need to press the reset switch on the demo board for the program to start. 

Is there any way around it? (I tried removing the 3V battery and replacing it back, no succes)

Basically I won't have room for the reset switch.

2) Once the initial app_closed_nfcprogramloader is replaced by my own code, there is no way to reflash the chip via NFC. I won't be able to reload the chip through LPC Link as I'm currently doing with the demo board.

Is there a way to include that boot loader with my custom program?

3) I'll be using the BGA version of the chip. My understanding is that all purchased chip have this  app_closed_nfcprogramloader.

After the various manufacturing steps (including xrays checks of the bga connections), is it guarantee that this nfcprogramloader remains fully operational? 

Thanks for your answers

Cyril

[EduardoZamora · Accepted solution]

Hello @CyrilBZH

Hope you are doing well.

1. According to NHS3152 DS, Section 8.3.2 Reset, the only reset sources on NHS3152 are RESETN pin, Watchdog reset, and software reset. A voltage drop should cause a reset.

2. This application is intended to be an NFC one-time Program Loader. Unfortunately, the source code of this program loader is not available. According to AN12328, Chapter 4, your application firmware could contain an update module which replicates the functionality of the “second stage boot loader”. However, this option is not available from the SDK and must be implemented by the customers themselves based on the documentation available in NHS3152 product page and NHS3152 SDK; you could refer to AN13041 for more information.

3. My apologies, we cannot guarantee an expected behavior if the device is operating outside the documented limiting values (NHS3152 DS).

Regards,
Eduardo.