[Help]How to configure PA15 PC13 PC14 PC15 as inputs on Libmaple core
Posted: Fri Jan 03, 2020 5:54 am
I am having some problems to configure these pins as inputs because they share other predefined functions at boot.
In the case of PA15 I have disabled the JTAG function so that it isn't used as JTDI. When I try to use it as input, it remains in activated state all the time. Doesn't matter if I set it as a floating, pull-up or pull-down input. Other JTAG pins as PB3 or PB4 work correctly.
PC13, PC14 and PC15 pins do act as inputs as they change state but they do in a strange way, toggling constantly as if they were connected to a clock that was causing this behavior.
I am using a blue pill, so I don't know if this behavior is due to the interference of the 32.768 Khz oscillator connected between PC14 and PC15 or LSE is not properly disabled. Do I need to desolder this oscillator to use the inputs correctly?
I would be grateful if someone who has managed to handle these pins correctly guides me on how to correctly configure the use of these pins as GPIO if possible for Libmaple core.
In the case of PA15 I have disabled the JTAG function so that it isn't used as JTDI. When I try to use it as input, it remains in activated state all the time. Doesn't matter if I set it as a floating, pull-up or pull-down input. Other JTAG pins as PB3 or PB4 work correctly.
PC13, PC14 and PC15 pins do act as inputs as they change state but they do in a strange way, toggling constantly as if they were connected to a clock that was causing this behavior.
I am using a blue pill, so I don't know if this behavior is due to the interference of the 32.768 Khz oscillator connected between PC14 and PC15 or LSE is not properly disabled. Do I need to desolder this oscillator to use the inputs correctly?
I would be grateful if someone who has managed to handle these pins correctly guides me on how to correctly configure the use of these pins as GPIO if possible for Libmaple core.