# Default Pin State at Start

**URL:** <https://forum.arduino.cc/t/default-pin-state-at-start/948059>\
**Category:** Nano RP2040 Connect\
**Created:** [January 17, 2022, 12:35pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059 "2022-01-17T12:35:41Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![blackbox-arduino](https://avatars.discourse-cdn.com/v4/letter/b/49beb7/32.png) [@blackbox-arduino](https://forum.arduino.cc/u/blackbox-arduino)\
**Post date:** [January 17, 2022, 12:35pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/1 "2022-01-17T12:35:41Z")

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Hello, is there an overview of the status of the each pin at the start of the RP2040 Connect?

I need the information for a project. Unfortunately, I can't find anything in the data sheet.

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**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\
**Post date:** [January 17, 2022, 12:38pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/2 "2022-01-17T12:38:17Z")

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Why not set the states explicitly yourself ?

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**Author:** ![blackbox-arduino](https://avatars.discourse-cdn.com/v4/letter/b/49beb7/32.png) [@blackbox-arduino](https://forum.arduino.cc/u/blackbox-arduino)\
**Post date:** [January 17, 2022, 12:47pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/3 "2022-01-17T12:47:33Z")

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Hello, thank you very much for your answer.

Of course I set the correct state in the setup function. I want to use the Arduino to control a large compressor.

In the time between switching on the RP2040 and the setup, however, I need a LOW signal.

Therefore the question which pins z. B. be pulled by pullup or pulldown or whether they floating.

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**Author:** ![J-M-L](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/j-m-l/32/766245_2.png) [@J-M-L](https://forum.arduino.cc/u/J-M-L)\
**Post date:** [January 17, 2022, 12:51pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/4 "2022-01-17T12:51:02Z")

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if you want to be sure - and especially if the Arduino can crash, not be powered etc then best is probably to use external pull down so that your compressor always sees known (safe), non floating values.

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**Author:** ![blackbox-arduino](https://avatars.discourse-cdn.com/v4/letter/b/49beb7/32.png) [@blackbox-arduino](https://forum.arduino.cc/u/blackbox-arduino)\
**Post date:** [January 17, 2022, 2:36pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/5 "2022-01-17T14:36:54Z")

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If the pin is floating at the start, then a pulldown is of course correct and not a problem.

However, if the pin is high at startup, then even a pulldown is useless.

Hence the question of whether the state of the pin at startup is documented. That way I can choose the right one.

As an example, the ESP8266 has pins that are low and high at start-up. It also has some that floating.

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**Author:** ![J-M-L](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/j-m-l/32/766245_2.png) [@J-M-L](https://forum.arduino.cc/u/J-M-L)\
**Post date:** [January 17, 2022, 3:30pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/6 "2022-01-17T15:30:00Z")

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fair point indeed. don't know.

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**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\
**Post date:** [January 17, 2022, 3:49pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/7 "2022-01-17T15:49:45Z")

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The pins default to being inputs with no pull up so that’s a float.

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**Author:** ![westfw](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/westfw/32/213443_2.png) [@westfw](https://forum.arduino.cc/u/westfw)\
**Post date:** [January 18, 2022, 11:24pm UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/8 "2022-01-18T23:24:24Z")

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Actually, the rp2040 chip defaults to being inputs with pull-down enabled.  
(in contrast to nearly every other microcontroller from all the other vendors. I can't decide whether this is a good idea, or not...) : [State of Pico I/O at powerup. - Raspberry Pi Forums](https://forums.raspberrypi.com/viewtopic.php?p=1956337&hilit=gpio+default+pull&sid=0965765be3f049419fbe94df73f738ef#p1956337)

 ![Screen Shot 2022-01-18 at 3.21.00 PM](https://europe1.discourse-cdn.com/arduino/original/4X/f/d/a/fda0a3da2e6953d3c8591a76a30a1a26b5d2eb9b.png)

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**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\
**Post date:** [January 19, 2022, 8:55am UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/9 "2022-01-19T08:55:50Z")

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Thanks, I missed that in the data sheet.  
I think that is a good default because that is what you need for when you are going to make it an output. Anything else can wait for the code to start running to get defined to what ever you want it to be.

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**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [July 18, 2022, 8:56am UTC](https://forum.arduino.cc/t/default-pin-state-at-start/948059/10 "2022-07-18T08:56:35Z")

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Closed on July 18, 2022, 8:56am UTC

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