Pin1.09 is initialized high at the beginning of code execution

RE: Pin1.09 is initialized high at the beginning of code execution

Kenneth — Tue, 23 Mar 2021 14:34:18 GMT

See your update now, good to hear you found the problem!

Kenneth

RE: Pin1.09 is initialized high at the beginning of code execution

Giannis Anastasopoulos — Tue, 23 Mar 2021 14:34:10 GMT

The issue was with the bootloader. There was some custom GPIO initialization there, that was setting the pin high

RE: Pin1.09 is initialized high at the beginning of code execution

Giannis Anastasopoulos — Tue, 23 Mar 2021 14:01:16 GMT

Dear Kenneth,

Based on what I see on the nRF52833DK, pin 1.09 is high by default. If I do not touch it the pin remains high, after the initialization of the gpio device, so I think that there is something special with this pin forcing it to behave differently.

I was able to verify this with my logic analyser (CHRG is the pin in question).

RE: Pin1.09 is initialized high at the beginning of code execution

Kenneth — Tue, 23 Mar 2021 12:05:35 GMT

The pin should not by default be setup for TRACE no, if you don't call nrf_drv_gpiote_init() does it stay high? Have you tried to pull it low with for instance a 1Mohm pull down, just to check by what amount it is pulled high? Can it be something nearby or connected to P1.09 pulling it high? All pins should by default be setup with floating/disconnect on power on reset, and if the pin was configured with TRACE, you would not be able to override the behavior by using nrf_drv_gpiote_init(). You can possible check the content of https://infocenter.nordicsemi.com/topic/ps_nrf52833/clock.html#register.TRACECONFIG

Kenneth