Does pyboard use RTC pin as GPIO

The official pyboard running MicroPython.
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shaoziyang
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Does pyboard use RTC pin as GPIO

Post by shaoziyang » Tue Sep 10, 2019 4:59 am

Does pyboard use RTC pin as general GPIO? I have try to turn off RTC in mpconfigboard.h, but when I set PC14/PC15 to OUT mode and set 1, it always get 0.

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jimmo
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Re: Does pyboard use RTC pin as GPIO

Post by jimmo » Tue Sep 10, 2019 3:31 pm

Can you explain in more detail. PC14/15 are the oscillator pins, and on the pyboard they aren't accessible on the headers.

PC13 is the RTC output on the STM32F405, which is available as X18 on the pyboard v1.1.

shaoziyang
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Re: Does pyboard use RTC pin as GPIO

Post by shaoziyang » Wed Sep 11, 2019 3:23 am

I need more GPIOs, and not use RTC. So I turn off RTC by set

#define MICROPY_HW_ENABLE_RTC (0)

but PC14/PC15 out value is not change.

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jimmo
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Re: Does pyboard use RTC pin as GPIO

Post by jimmo » Wed Sep 11, 2019 4:01 am

Right but I'm confused because PC14/15 aren't actually accessible on the pyboard headers (so how are you accessing them?), and furthermore, they are unrelated to the RTC.

shaoziyang
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Re: Does pyboard use RTC pin as GPIO

Post by shaoziyang » Wed Sep 11, 2019 1:06 pm

I use a multimeter to measure voltage on capacitor, it is not change.

Or read the pin value, it always zero.

Code: Select all

PC14=Pin('PC14', Pin.OUT)
PC14(1)
PC14()

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jimmo
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Re: Does pyboard use RTC pin as GPIO

Post by jimmo » Wed Sep 11, 2019 2:01 pm

Are you using HSI or HSE?

Also, which pyboard do you have? I'm guessing that because Pin('PC14') worked, you have PYBLITE1.0?

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