Unable to set P0.01 as a GPIO output

RE: Unable to set P0.01 as a GPIO output

hjklas — Thu, 23 Jun 2022 23:50:44 GMT

After testing out these two pins (P0.00 and P0.01) on a custom board of ours it seems to work fine. This means it wasn't a firmware issue but some kind of issue with the mbn52832 dev board. I am still confused as to why it didn't work since I put the 0 ohm resistors in the right place and even tried on two different boards.

RE: Unable to set P0.01 as a GPIO output

hjklas — Thu, 23 Jun 2022 17:17:09 GMT

Yes, I have a tested a few other pins. Only P0.00 and P0.01 do not work.

RE: Unable to set P0.01 as a GPIO output

Vidar Berg — Thu, 23 Jun 2022 07:45:07 GMT

Just to make sure, have you verified if you are able to toggle other pins if you only change out the pin number in your code?

RE: Unable to set P0.01 as a GPIO output

hjklas — Wed, 22 Jun 2022 20:19:25 GMT

I have done something similar where I am continuously checking LFCKLSRC to make sure it is set to the internal RC at all times.

RE: Unable to set P0.01 as a GPIO output

hmolesworth — Wed, 22 Jun 2022 19:40:16 GMT

Perhaps have a look at the LFCLKSRC register; maybe it is not cleared correctly; both pins are either i/o or crystal, This is some code I posted a few years ago:

// Note 32kHz Osc pins can be both used as GPIOs or both used as 32kHz Crystal Oscillator
if ( (ThisPinId == PIN_NRF_XL2) && (NRF_CLOCK->LFCLKSRC & 0x000001) ) return "RTC-OSC-OUT";
if ( (ThisPinId == PIN_NRF_XL1) && (NRF_CLOCK->LFCLKSRC & 0x000001) ) return "RTC-OSC-IN";

RE: Unable to set P0.01 as a GPIO output

hjklas — Wed, 22 Jun 2022 18:59:26 GMT

I have performed continuity tests to ensure the connection from the resistor to the pin. There doesn't seem to be a way I can directly probe the output pin on the mcu.

I can't think of anything else to test at this point, it seems like I have hit a dead end.

RE: Unable to set P0.01 as a GPIO output

Vidar Berg — Wed, 22 Jun 2022 11:27:12 GMT

Hello Harrison,

Strange. I looked over schematics again, and I don't see anything else that needs to be changed to route the XL IOs to the pin header. Only suggestion I can think of at this point is that you try to perform a continuity test to verify the connection.

Best,

Vidar

RE: Unable to set P0.01 as a GPIO output

hjklas — Tue, 21 Jun 2022 17:44:58 GMT

Hello Vidar,

I am seeing the same result after running your project. The XL1 and XL2 pins are staying low the whole time. There shouldn't be any other hardware changes besides moving the 0 ohm resistors correct?

Best,

Harrison Klas

RE: Unable to set P0.01 as a GPIO output

Vidar Berg — Tue, 21 Jun 2022 13:21:18 GMT

Hello,

It sounds like you have performed all the neccessary steps. That is, made sure the pins are routed to the pin header by moving the 0 ohm resistors, and made sure that the LF crystal oscillator was not enabled. Could you run to run the project or program the hex file below and see if it gives the same result? I verified that it worked on a nRF52 DK here.

devzone.nordicsemi.com/.../blinky_5F00_pca10040_5F00_toggle_5F00_xl1_5F00_and_5F00_xl2.hex

devzone.nordicsemi.com/.../blinky_5F00_use_5F00_xl_5F00_pins_5F00_as_5F00_gpio.zip

Thanks,

Vidar