RE: Combining GPIOTE and high-drive capability

Boris Matešin — Thu, 04 Jul 2019 12:03:58 GMT

Hi, Håkon,

thanks for linking the referent registers and fields. I remember testing out S0H1 mode at one point in the past, but that was for a very specific use-case (not related to induction loads).

Thanks for the warning about induction loads - I think we'll switch to driving a FET instead of driving the pin directly.

Best regards,

-- Boris

RE: Combining GPIOTE and high-drive capability

Håkon Alseth — Thu, 04 Jul 2019 11:53:58 GMT

Hi,

The drive strength is set in the GPIO PIN_CNF[my_pin] register, field DRIVE:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/gpio.html?cp=3_1_0_19_2_9#register.PIN_CNF-0

Here's an example for setting H0H1 with the help from nrf_gpio.h:

nrf_gpio_cfg(
pin_number,
NRF_GPIO_PIN_DIR_OUTPUT,
NRF_GPIO_PIN_INPUT_DISCONNECT,
NRF_GPIO_PIN_NOPULL,
NRF_GPIO_PIN_H0H1,
NRF_GPIO_PIN_NOSENSE);

Set it back to normal S0S1 by calling nrf_gpio_cfg_output.

[quote user=""]in order to actuate a particularly current-hungry relay or other peripheral.[/quote]

You should be very careful with induction loads and driving these directly from a GPIO. You can get high transients directly into the GPIO when pulsing inductive loads, and go outside the maximum ratings of the nRF device, thus permanently damaging the GPIO or chip. Have you considered using a mosfet to drive these loads?

Kind regards,

Håkon