Using the NFC pins as GPIO breaks SPI instance

RE: Using the NFC pins as GPIO breaks SPI instance

RK — Sun, 24 Dec 2017 12:25:21 GMT

The UICR value is sticky across resets, if it wasn't then nothing would work. The code is in the gcc tool section so you'd expect it to work. I don't even vaguely get how setting the NFC pin register could affect SPI, but if there's a better way to enable it, I'd just use that.

RE: Using the NFC pins as GPIO breaks SPI instance

Eliot Stock — Sun, 24 Dec 2017 10:27:14 GMT

@RK Because I was following this answer and that didn't make it clear that using CONFIG_NFCT_PINS_AS_GPIOS alone was sufficient, even for gcc: devzone.nordicsemi.com/.../

RE: Using the NFC pins as GPIO breaks SPI instance

RK — Sun, 24 Dec 2017 00:14:33 GMT

Why don't you just use the standard method of setting the NFC pins off by defining CONFIG_NFCT_PINS_AS_GPIOS. The system_nrf52.c file will then fix it on first run and reset. Done. All this messing about with linker maps just isn't necessary

RE: Using the NFC pins as GPIO breaks SPI instance

Eliot Stock — Sat, 23 Dec 2017 12:58:05 GMT

I think you mean the value should be 0xFFFFFFFE, not 0x01. I can get both the GPIO and the SPI to work only if I write to the UICR using nrfjproj before flashing my code. I can't get it to work using the const in code, even when setting the correct value. Will add my linker script above. The nrfjproj approach is a bit of a hack, so I'd like to get this working in code.

RE: Using the NFC pins as GPIO breaks SPI instance

Hung Bui — Fri, 22 Dec 2017 13:03:41 GMT

I would suggest you to try writing to UICR (to the address 0x1000120c) using nrfjprog, just for testing first. Check if both GPIO and SPI work or not.

If that work then you need to check your attribute declaration, I don't see you set it to a value (should be 0x01). This is how we set the address of the bootloader in UICR:

   volatile uint32_t m_uicr_bootloader_start_address  __attribute__ ((section(".uicr_bootloader_start_address")))
                                            = BOOTLOADER_START_ADDR;