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I'm using the SparkFun nRF52832 Breakout to use the RTC signal for a sensor pressure clock line.

Unfortunately, on the two RTC pins, there are no signals. To verify this point, I used an oscilloscope to read pins 0 and 1.

Besides, I also created a sketch on another pin to generate my own square signal close to 33.333kHz, and I saw it on the oscilloscope.

I understand according to this tutorial that I do not need to modify the hardware.

RTC-EN - Connect/Disconnect the 32.768kHz Crystal

The nRF52832 Breakout equips the chip with a 32.768kHz crystal – connected to GPIO pins 0 and 1. Unfortunately, those pins make up a quarter > of the available ADC inputs. So, if your application doesn’t require an RTC – and you need those pins to for another purpose – grab a hobby knife and cut the two traces between their pads to disconnect the crystal.

Maybe I need to init the RTC pin with a dedicated method, but which one? Could you provide me a link to any tutorial?

Any ideas what I'm missing here? What is my misunderstanding?

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Ugo
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  • The crystal connects to pins 0 and 1, I'm not sure why you are trying to scope those lines. Are you trying to get an RTC signal to output to some GPIOs? Please provide some code and I can try to help you. You should take a look at the Nordic SDK, I'm sure there is an RTC example there. – Catsunami Nov 26 '18 at 19:17
  • Hello Catsunami, Yes I'm trying to scope those lines just to see crystal tick. And yes I hope to use directly either those lines, or another GPIO to have a clock = 32.768kHz. I will check the Nordic SDK, thanks for this advise. – Ugo Nov 30 '18 at 17:59
  • The crystal tick isn't a 0-3.3V signal that you might be expecting. I'd set up a timer to use the 32kHz clock as an input and toggle a GPIO in response (you'll get 1/2 of the frequency though). – Catsunami Dec 14 '18 at 17:36

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