0

As the title implies. thank you in advance.

6
  • 2
    All of them have.
    – Gerben
    Jan 7 '20 at 15:45
  • which pins are you referring to?
    – jsotola
    Jan 7 '20 at 16:11
  • 1
    all Digital I/O pins 0 to 13 and A0 to A5. Jan 7 '20 at 16:12
  • just wanted to be sure
    – jsotola
    Jan 7 '20 at 16:25
  • 2
    Note that you need to initialize the pins as INPUT_PULLUP to actually enable the pullup resistor. (Just in case this isn't clear.)
    – orithena
    Jan 9 '20 at 11:25
3

All of them. It's a standard feature on all IO pins in the AVR range.

7
  • Thank you very much :) This is NOT the case in other Microcontrollers am I right? Jan 7 '20 at 15:50
  • 2
    Not all microcontrollers have them, that is true (low-end PIC for example). Some only have them on some pins (such as older PIC32MX chips). They are getting more and more popular though (now all modern PIC32MX chips and PIC32MZ chips have them), so more modern chips tend to have them rather than not.
    – Majenko
    Jan 7 '20 at 15:52
  • 1
    Also some MCUs (such as STM32) have also pull down resistors. Jan 7 '20 at 16:18
  • 2
    @MichelKeijzers So do modern PIC32 chips (anything since the release of the MX1 / MX2 series).
    – Majenko
    Jan 7 '20 at 16:23
  • 1
    Note that while all all AVR chips offer pull-up resistors, you have to turn them on. To do that, use the command pinMode(pin, INPUT_PULLUP) to activate the pullup resistor on the pin pin
    – Duncan C
    Jan 7 '20 at 21:34

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