nRF9160 DK I/O expander

[Francis S]

The nRF9160 DK has an I/O expander that can optionally be used to interface the LEDs, slide switches, and buttons.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fug_nrf91_dk%2FUG%2Fnrf91_DK%2Fintro.html&cp=2_0_4

Any sample code available on how to interface to the I/O expander. 

[helsing]

Hello Francis,

I will check if anything else is available. Will you be interfacing the I/O expander from nRF9160 or from nRF52840? So far I have only found the PCAL6408A driver for nRF5 SDK, v17.0.2.

Best regards,

Håkon

[Francis S]

Hello Håkon

I plan to use the I/O expander from nRF9160.

[helsing]

Thanks.

How do you intend to use the I/O expander? Is your goal to operate and interact with the LEDs, slide switches and buttons? Or are you looking for detailed control of the I/O expander itself?

If the goal is to operate the LEDs, slide switches and buttons then basic Zephyr samples such as Blinky and Button are available. The button and LED definitions of nRF9160 DK can be found in boards/arm/nrf9160dk_nrf9160/nrf9160dk_nrf9160_common.dts.

[Francis S]

I am working on a client demo using the nRF9160 DK. The demo includes an arduino relay board with required pins same as the led's, slider and buttons on the DK. To enable the arduino board I had to configure the arduino config on the pins. (CONFIG_BOARD_NRF9160DK_LED1..4_ARDUINO=y...)

This leaves me with no led's or input to complete the demo.   

[helsing]

Thank you for the explanation. I am looking for a solution.

[helsing]

I am not yet at the bottom of this. Here is what I am looking into at the moment: This section about the Board controller should provide some clues. It looks like the way to configure the I/O expander is to change the CONFIGs of the nRF52840 firmware. Also take a look at the nRF9160 DK board control sections showing possible routing.