Looking at the GPIO API I see a function called gpio_set_pull_mode(). I'm wondering how to describe this function. For input, I can imagine no signal (floating input) being treated as high with "pull up" and low with "pull down". What then does the option GPIO_PULLUP_PULLDOWN mean?
Does this function have any semantics for GPIO pins flagged as "output"?
[Answered] Meaning of GPIO_PULLUP_PULLDOWN
[Answered] Meaning of GPIO_PULLUP_PULLDOWN
Last edited by kolban on Wed Dec 28, 2016 10:56 pm, edited 1 time in total.
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Re: Meaning of GPIO_PULLUP_PULLDOWN
*bump*
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Re: Meaning of GPIO_PULLUP_PULLDOWN
This took me a moment to understand as well, had to check with coworkers. Setting GPIO_PULLUP_PULLDOWN turns on both pull-up and pull-down resistors, which pulls the pin voltage to approximately VCC/2.
Not useful for digital GPIO functions, but you can use this to bias the input when sampling an analog signal.
Not useful for digital GPIO functions, but you can use this to bias the input when sampling an analog signal.
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