"forbidden" levels on input port

[taui]

Hello,

we want to get three different states using only one GPIO:

1. nRF52840 GPIO output driven low

2. nRF52840 GPIO output driven high (3V3)

3. nRF52840 GPIO internal unconnected or input (external resistor divider feeds 1.65volts to the GPIO port)

Is it allowed to feed 1.65V (nRF52840 works with 3V3) to an input/internal unconnected GPIO port?

regards Thomas

[Håkon Alseth]

Hi,

Is it allowed to feed 1.65V (nRF52840 works with 3V3) to an input/internal unconnected GPIO port?

GPIOs can be applied with voltages between GND to VDD, as described in the datasheet:

https://docs.nordicsemi.com/bundle/ps_nrf52840/page/abs_max_ratings.html

 

You can, on the fly, reconfigure the GPIO to input/output/pull etc. via the NRF_GPIO->PIN_CNF[] register.

 

Kind regards,

Håkon