Why would a GPIO pin stop working?

[DimitraN]

I have been working on nRF52832 project for many days now, using GPIO pins to connect to a HX711 adc for a loadcell, and some other to connect to an Arduino board. 
Suddenly, GPIO pin 23, which was configured as input and connected to DOUT of the HX711, stops working. I mean that I first noticed that I could no longer read anything from that pin and I also checked with a polymeter that by using nrf_gpio_pin_set() and nrf_gpio_pin_clear() commands, the state of the pin changes from ~2.89 V to ~2.86 mV. I only notice a difference in milliVolts, and it never "clears" to low level 0V. 

So, my question is if there is a chance I created this problem. Is there any way I could damage a GPIO pin? I would like to so that I would avoid that in the future. Or could it be caused by other connections to GPIO pins?

One more information, is that HX711 was connected to 5V pin on nRF52832 in the past, however for weeks now it was connected to Vdd of nRF52832. 

Thanks in advance and I apologise if my question is silly.

[Jørgen Holmefjord]

Hi,

As described in Absolute maximum ratings, the voltage on a GPIO should never exceed VDD+0.3V, or 3.9V if VDD=3.6V. If the sensor have input 5V to the GPIO, this might have damaged the pin.

Have you tested with a minimal example, if you can control the pin using nrf_gpio_cfg_output()/nrf_gpio_pin_set()/nrf_gpio_pin_clear() functions?

Best regards,
Jørgen

[DimitraN]

Jørgen Holmefjord said:

Have you tested with a minimal example, if you can control the pin using nrf_gpio_cfg_output()/nrf_gpio_pin_set()/nrf_gpio_pin_clear() functions?

Yes I tested the pin with these functions as I mentioned and the voltage I measured 2.89V and 2.86 V for high and low accordingly. Probably it was damaged by the sensor I guess as you confirmed. Thank you very much.