Why there are some pins cant be the ss pin of SPI

RE: Why there are some pins cant be the ss pin of SPI

Simonr — Mon, 15 Feb 2021 09:00:14 GMT

The nRF51822 does not support NFC, and therefore does not have NFC pins that need configuring. Please check out the SPI examples in SDK v12.3, which is the latest one supporting the nRF51 series devices.

This case is specific to the nRF52's use of some GPIOs. If you're having trouble with setting up a project. Please create a ticket of your own where you describe your issue in detail.

Best regards,

Simon

RE: Why there are some pins cant be the ss pin of SPI

Aditya Jethva — Sun, 14 Feb 2021 19:49:44 GMT

Can you share me the whole code , i tried in NRF51822 but not getting the data .

RE: Why there are some pins cant be the ss pin of SPI

Nguyen Hoan Hoang — Thu, 26 Mar 2020 04:02:23 GMT

Pin 9 is by default NFC. To use it, you need to configure in the UICR register for that pin to act as GPIO.

    /* Configure NFCT pins as GPIOs if NFCT is not to be used in your code. If CONFIG_NFCT_PINS_AS_GPIOS is not defined,
       two GPIOs (see Product Specification to see which ones) will be reserved for NFC and will not be available as
       normal GPIOs. */
    #if defined (CONFIG_NFCT_PINS_AS_GPIOS)
        if ((NRF_UICR->NFCPINS & UICR_NFCPINS_PROTECT_Msk) == (UICR_NFCPINS_PROTECT_NFC << UICR_NFCPINS_PROTECT_Pos)){
            NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NRF_UICR->NFCPINS &= ~UICR_NFCPINS_PROTECT_Msk;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NVIC_SystemReset();
        }
    #endif