Not able to get output as expected on GPIO port on board nrf52840 DK

RE: Not able to get output as expected on GPIO port on board nrf52840 DK

Håkon Alseth — Tue, 23 Mar 2021 08:47:52 GMT

Your LEDs needs more current than the nRF can provide in the gpio output configuration.

You should use a transistor to switch on/off your LEDs.

RE: Not able to get output as expected on GPIO port on board nrf52840 DK

Brainson — Sun, 21 Mar 2021 10:39:21 GMT

yes i used buffer but its only work for switch, what is logic for CTL and Dimming, please give proper answer.

RE: Not able to get output as expected on GPIO port on board nrf52840 DK

Håkon Alseth — Fri, 05 Mar 2021 09:02:56 GMT

Hi,

Those GPIOs go directly to the LEDs, as described here:

https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_buttons_leds.html?cp=4_0_4_7_6

Note that your LEDs on the breadboard likely draw alot of current, please see the the GPIO electrical specification about sink/sourcing of current directly from GPIOs:

https://infocenter.nordicsemi.com/topic/ps_nrf52840/gpio.html?cp=4_0_0_5_8_2#unique_524997740

I would recommend that you consider a transistor buffer to turn on/off the external LEDs.

Kind regards,

Håkon

RE: Not able to get output as expected on GPIO port on board nrf52840 DK

Brainson — Thu, 04 Mar 2021 13:03:47 GMT

Please reply fast

RE: Not able to get output as expected on GPIO port on board nrf52840 DK

Håkon Alseth — Thu, 04 Mar 2021 12:04:11 GMT

Hi,

Do you have a schematic on how these LEDs are connected?

Kind regards,

Håkon