Open Drain output for GPIOTE task pin

[IanAber]

It appears that when setting a GPIO pin up to be used by the GPIOTE module as an output task the GPIOTE module takes over the configuration of the pin. It does not appear that it is possible to set the pin in Open Drain configuraiton as you can with the GPIO module itself because GPIOTE overrides this as soon as the task is enabled. Is this correct or am I missing something obvious?

[IanAber]

Playing around with this I found that I could reconfigure the port pin immediately after enabling the GPIOTE task so it becomes open drain instead of a totem pole output. Is this the right way to do it though? Seems like there ought to be a way to set the port up as open drain before it gets enabled by GPIOTE. I did set the output to be initially low so the port does not try to drive the pin high before it is reconfigured but this does not seem ideal.

[Sigurd]

Hi,

If you don't want the GPIOTE to change the GPIO configuration, you can set the skip_gpio_setup flag to true

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.6.1/nrfx/drivers/gpiote/driver.html#c.nrfx_gpiote_in_config_t.skip_gpio_setup

https://github.com/nrfconnect/sdk-hal_nordic/blob/v1.5.1/nrfx/drivers/include/nrfx_gpiote.h#L50

https://github.com/nrfconnect/sdk-hal_nordic/blob/v1.5.1/nrfx/drivers/src/nrfx_gpiote.c#L689

[IanAber]

I am using the GPIOTE channel to configure an output. The nrfx_gpiote_out_config_t strructure does not contain the skip_gpio_setup flag. It only appears to be available in the input configuration structure.

[Sigurd]

Hi,

Yes, it seem that nrfx_gpiote_out_init() will configure the pin with nrf_gpio_cfg_output() to be NRF_GPIO_PIN_S0S1 (///< Standard '0', standard '1'.)

You wanted to use one of these other drive modes?

/** @brief Enumerator used for selecting output drive mode. */
typedef enum
{
    NRF_GPIO_PIN_S0S1 = GPIO_PIN_CNF_DRIVE_S0S1, ///< Standard '0', standard '1'.
    NRF_GPIO_PIN_H0S1 = GPIO_PIN_CNF_DRIVE_H0S1, ///< High drive '0', standard '1'.
    NRF_GPIO_PIN_S0H1 = GPIO_PIN_CNF_DRIVE_S0H1, ///< Standard '0', high drive '1'.
    NRF_GPIO_PIN_H0H1 = GPIO_PIN_CNF_DRIVE_H0H1, ///< High drive '0', high drive '1'.
    NRF_GPIO_PIN_D0S1 = GPIO_PIN_CNF_DRIVE_D0S1, ///< Disconnect '0' standard '1'.
    NRF_GPIO_PIN_D0H1 = GPIO_PIN_CNF_DRIVE_D0H1, ///< Disconnect '0', high drive '1'.
    NRF_GPIO_PIN_S0D1 = GPIO_PIN_CNF_DRIVE_S0D1, ///< Standard '0', disconnect '1'.
    NRF_GPIO_PIN_H0D1 = GPIO_PIN_CNF_DRIVE_H0D1, ///< High drive '0', disconnect '1'.