# Ender 3 Max 4.2.2 with Bltouch Filament sensor is reversed
**URL:** https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624
**Category:** Support
**Created:** [24 March 2023 15:21 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624 "2023-03-24T15:21:52Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@lilFonsi](https://marlin.crc.id.au/forum/u/lilFonsi)
#### Post date: [24 March 2023 15:21 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/1 "2023-03-24T15:21:52Z")
Hi everyone!
Thank you for this amazing service and forum, I have a quick question regarding my Ender 3 Max everything is stock, I am using the latest available nightly firmware, but as some have reported after my research, the filament sensors signal is being reported backwards, is it possible to provide me with the nightly settings for my printer, so i can build a firmware with the signal reversed?
Everything else works perfectly!
Thank you!
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### Author:  [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [26 March 2023 03:01 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/2 "2023-03-26T03:01:11Z")
I’d suggest reversing the wires to switch instead of via firmware - otherwise you’ll have to do this firmware modification every time you get a new firmware.
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### Author:  [@lilFonsi](https://marlin.crc.id.au/forum/u/lilFonsi)
#### Post date: [26 March 2023 22:26 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/3 "2023-03-26T22:26:35Z")
Hi Thanks for the Quick reply,
I agree 100%, I have tried that but not sure if I’m doing it correctly, or if the micro switch i have will allow me.
This is the Switch i have, perhaps someone can point me in the right direction if your not familiar with it?
Thank you for all the help!
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### Author:  [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [27 March 2023 03:56 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/4 "2023-03-27T03:56:17Z")
Sorry - I caught COVID while out on a company trip - and my brain is complete fuzz right now.
In theory, you should swap the V and G wires. You can test this with a multimeter on the **S** ignal wire and confirm that the order of operation is reversed.
This _should_ change it from active HIGH to active LOW…
However, be careful with this because my brain is fuzz right now and I’d love it if someone could confirm this to make sure I haven’t made a grave error.
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### Author:  [@lilFonsi](https://marlin.crc.id.au/forum/u/lilFonsi)
#### Post date: [8 April 2023 15:47 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/5 "2023-04-08T15:47:42Z")
Good evening,
sorry for the long delay! Hope you are feeling better! I did test it with a multimeter and it did reverse the signal, and everything seems to be working great! only thing I noticed is the little light does not turn on anymore but wtv!
Thank you for all the help!
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### Author:  [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [8 April 2023 19:59 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/6 "2023-04-08T19:59:47Z")
Thanks - I’m mostly recovered now - just in time to go on another work trip to the same location again! Hopefully no COVID this time! 😃
Good to hear about the sensor. I wonder if the LED will now light up in the reverse - ie filament out instead of filament present. It may just not work at all - but at least the configuration is somewhat standard now.
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### Author:  [@system](https://marlin.crc.id.au/forum/u/system)
#### Post date: [10 April 2023 19:59 UTC](https://marlin.crc.id.au/forum/t/ender-3-max-4-2-2-with-bltouch-filament-sensor-is-reversed/1624/7 "2023-04-10T19:59:50Z")
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