How to set GPIO pin to 0 volts

RE: How to set GPIO pin to 0 volts

CBD — Wed, 29 Mar 2017 10:16:18 GMT

As noted nrf_gpio_cfg_output(25) will set port0.25 as an output. nrf_gpio_pin_clear(25) will set port0.25 to 0 volts.

However, this is reliant on the port0.25 line not being driven high by other hardware on your board. Have you made sure that this isn't the case?

You could check this by setting the pin as an input and leave it free floating e.g. nrf_gpio_cfg_input(25, NRF_GPIO_PIN_NOPULL); , and then measure the voltage.

If a voltage is read that is somewhere in between ground and supply voltage then try grounding the line momentarily, to discharge any held charge, and then rechecking. A non-zero or near zero voltage will indicate that the line is being supplied form somewhere.

RE: How to set GPIO pin to 0 volts

Daniel Wang — Tue, 28 Mar 2017 18:34:58 GMT

nrf_gpio_cfg_output(25); //config pin P0.25 as output

nrf_gpio_pin_clear(25); //set the pin low

RE: How to set GPIO pin to 0 volts

Jørgen Holmefjord — Tue, 28 Mar 2017 07:26:58 GMT

Have you configured the GPIO as output and set it to low? You can find the relevant functions in the GPIO abstraction documentation. If not configured, the pins will be left floating.