Question about set GPIO pin status

[Leogean]

Hi,

I have a question about setting the gpio pin status. From the picture, it seems that the value on the right represents the status of the gpio pin. So the default value is 2, which means using input mode and disconnecting with input buffer, right? Can we set the status by writing the value with "nrf_gpio_pin_write".  For example, "nrf_gpio_pin_write(17,1)" and "gpio_pin_cfg_output(17)", are those two sentences have the same function?

Actually, I have tried to use "nrf_gpio_pin_write", but it never works. I have configured the corresponding pin as output, but I still cannot write value to that pin. Could you please tell me what is the possible reason for this? 

Thanks in advance for your help.

[Jørgen Holmefjord]

Hi,

The state of the pin is not reflected in the PIN_CFG register, you need to read the IN register to get the state of pins configured as inputs. To read state of pins configured as outputs, you can read the OUTSET register.

nrf_gpio_pin_write() will only call nrf_gpio_pin_clear() or nrf_gpio_pin_set(), depending on the second argument (0 will clear, 1 or above will set).

Best regards,
Jørgen

[Leogean]

Ah, I understand, thanks a lot for the detailed explanation.