nrf52840 pin 0.19 detected floating voltage as high input

[michael_chou]

Hi,

When I define my nrf52840 pin 0.19 as input put, and there is no connection to any sensor.

Then I use gpio_pin_get_dt() to get pin 0.19 status, the status is high.

Even if I reset the pin 0.19 status, it will return high in 10 seconds.

I guess the root cause is the null connection with floating voltage cause nrf52840 to define pin 0.19 as high.

How can I modify the gpio config to avoid the floating voltage?

Thanks! 

I have already disable the qspi dts in my nrf52840dk_nrf52840.overlay file, so the qspi node won`t use pin 0.19.

[Simonr]

Hi

The easiest suggestion would be to add a pull-down to the P0.19 so it will be kept low. What exactly do you need it to stay low for in your application? You could also set it to disconnected in SW to keep it from changing state.

I assume you're working on a custom board, correct? If so I assume you have the VDD or radio line (or similar) close to the P0.19 trace that causes it to jump high when it's floating.

Best regards,

Simon