# \[output\_in\] and alternative voltage

**URL:** <https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394>\
**Category:** General Discussion\
**Created:** [March 25, 2022, 7:40am UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394 "2022-03-25T07:40:27Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Skippythekangoo](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Skippythekangoo](https://klipper.discourse.group/u/Skippythekangoo)\
**Post date:** [March 25, 2022, 7:40am UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394/1 "2022-03-25T07:40:27Z")

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Morning all.

I had remove LCD Ribbon cable on my old Ender 3 2018 version, with Melzi 1.1.3 motherboard.

I have enable PA3 pin to hight voltage in

[output\_pin VCC\_TOUCH]  
pin: PA3  
value: 1

But I have a alernatif signal in output with oscilloscope.

 ![16481938758766163255949773037476](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/3/34b04eebfb8e019946b0b70f6b49b56f9a507bc3.jpeg)

How can I have a clear hight signal (+5V)…???

 ![16482013407435684057587159381875](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/a/a459ec3a83f78c6a34f7362a0046840aa0fbd1a4.jpeg)

Thank you lot.

P.S. Sorry for my english, I’m so french…

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**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\
**Post date:** [March 25, 2022, 12:20pm UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394/2 "2022-03-25T12:20:39Z")

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When you toggle the pin high, Klipper will instruct the MCU to toggle the respective pin to its high state. What “high” means is up to the board and also how clear the “high” is up to the hardware.

Typically the pins of the printer boards are 3V3, so high should be around 3V3. If you need 5V then you would need to use a level shifter.

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**Author:** ![Skippythekangoo](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Skippythekangoo](https://klipper.discourse.group/u/Skippythekangoo)\
**Post date:** [April 1, 2022, 4:33am UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394/3 "2022-04-01T04:33:41Z")

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Thank for your reply.

But I have some question about this.

A signal isn’t continue, not on a ground, and a voltage is about 4.6V, between 3.3V and 5V, not regular voltage.

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**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\
**Post date:** [April 1, 2022, 6:34am UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394/4 "2022-04-01T06:34:00Z")

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I guess it would be best to ask in a community that is dedicated to electronics. Klipper just toggles the pin high. What your board makes out of it, is entirely up to the board’s hardware.

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**Author:** ![Skippythekangoo](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Skippythekangoo](https://klipper.discourse.group/u/Skippythekangoo)\
**Post date:** [April 1, 2022, 6:35am UTC](https://klipper.discourse.group/t/output-in-and-alternative-voltage/2394/5 "2022-04-01T06:35:46Z")

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OK.

Thanks for all.

I go to search about electronic groups…

Best regard…