Friends, would like to ask a question about the input port
Chip: STM32F103RFT6
PC3 used as input
Phenomenon 1:
When the PC3 mode is set as a pull-up input, regardless of whether the peripheral is 3.3V or 0V for this pin, the result read by the MCU is always high.
Phenomenon 2:
When the PC3 mode is set as a pull-down input, regardless of whether the peripheral is 3.3V or 0V for this pin, the result read by the MCU is always low.
What is the reason, please advise.
Yuri ポストする December 10, 2020
That's not right, how did you give 0V to the peripheral circuit for the pull-up input? Ground? It's best to post the program and show it to you.
Lars ポストする December 10, 2020
Configuration problem.
Janna ポストする December 10, 2020
It is recommended that you use a 100 ohm resistor to connect this pin to ground under test.
