Is any additional settings needed be configures for GPIO9 and 10

[Jorgewu]

Hi all: Based the descriptions in data sheet, the GPIO9 and 10 are set to NFC antenna pins by default. And I cannot control these 2 pin correctly by configuring the pins as below

NRF_GPIO->PIN_CNF[OLED_RESET_PIN_NUMBER] =
        (GPIO_PIN_CNF_DIR_Output        << GPIO_PIN_CNF_DIR_Pos)
      | (GPIO_PIN_CNF_INPUT_Connect     << GPIO_PIN_CNF_INPUT_Pos)
      | (GPIO_PIN_CNF_PULL_Disabled     << GPIO_PIN_CNF_PULL_Pos)
      | (GPIO_PIN_CNF_DRIVE_S0S1        << GPIO_PIN_CNF_DRIVE_Pos)
      | (GPIO_PIN_CNF_SENSE_Disabled    << GPIO_PIN_CNF_SENSE_Pos);
      nrf_gpio_pin_set(OLED_RESET_PIN_NUMBER);

Can you tell me what additional settings I need implement?

Below are the descriptions showed in datasheet

20.2.2 NFC antenna pins

Two physical pins can be configured either as NFC antenna pins (factory default), or as GPIOs P0.09 and P0.10.

When configured as NFC antenna pins, the GPIOs on those pins will automatically be set to DISABLE state and a protection circuit will be enabled preventing the chip from being damaged in the presence of a strong NFC field. The protection circuit will short the two pins together if voltage difference exceeds approximately 2V.

[Wojtek]

Yes, you should clear NFCPINS register in UICR. (value 0 means that pins works as gpio, but by default this register contains 0xFFFFFFFF which means that pins are used as NFC antenna).

I think you should use NVMC to write to UICR...

[jixing.zou]

See this link text

[Jorgewu]

Please use the API of NVMC to write it..