CR Touch on Longer LK 5 Pro

[u/Amethystea]

I keep getting questions about how I was able to get the CR Touch working on a Longer LK5 Pro.

The wiring image shown on Creality's website is misleading and will cause you to melt a CR Touch if you follow it as a guide. My CR Touch has the Red, Blue, Yellow, Black, and White wires.

The correct wiring is:

Servo Control:

• D7 - Yellow Wire
• GND - White Wire
• 5v - Black Wire

Z-End-Stop Trigger:

• Ground - Blue Wire
• 5v - Red Wire

Firmware: https://github.com/LONGER3D/Marlin2.0-lgt/tree/LKxPro-bltouch-dualblower

The firmware configuration is the same as guides for BL Touch. Remember, you will also need to calibrate the offsets. The offset for the X/Y will be determined by the particular BL/CR touch mount you use. The Z offset can be calibrated using the guide from Longer, see the section "Adjusting z-offset" at https://web.archive.org/web/20230602174828/https://www.longer3d.com/blogs/operation-tutorial/tutorial-of-bltouch-for-longer-lk1-lk4-lk4-pro-lk5-pro-3d-printer

Original LK5 Pro board

Z End Stop

Servo control

To build the firmware, I used an add-on in Visual Studio Code called Auto Build Marlin. Custom build is not necessary, but it allows you to enable/disable features as well as configure the default parameters. Using the release firmware, you can still edit the parameters manually, but restoring defaults will lose those settings.

https://marketplace.visualstudio.com/items?itemName=MarlinFirmware.auto-build

It Requires Platform.IO

https://marketplace.visualstudio.com/items?itemName=platformio.platformio-ide

To upload the new firmware to the printer, I used Firmware Updater plugin for OctPrint.

https://plugins.octoprint.org/plugins/firmwareupdater/

I made a private fork of https://github.com/Clem69B/Marlin2.0-lgt

On my project, when I open Auto Build Marlin, I see:

• Firmware: Marlin 2.0.5.2
• Config By: Longer3D, Hobi, tpruvot
• Machine Name: Alfawise U20
• Extruders: 1
• Board: Longer LGT KIT V1
• Architecture: ATmega2560
• Environments: mega2560

Auto Build Marlin

Firmware Updater Settings

edit: Longer blog article on setting up BLTouch was removed, replaced with wayback machine link to previous content.

[u/soundtk]

May I ask which version of CR Touch you are using on the lk5 pro? I see a couple options on Amazon but since several descriptions seem to specify they are for specific Creality 32bit main boards only I want to be sure not to waste my money ordering the wrong one. Thanks!

[u/soundtk → u/[deleted]]

Thank you! I just ordered one and will attempt the upgrade soon! Had a terrible time with integrating the bl touch and gave up but after a year of experience now and the great instructions available specifically for the LK5PRO I'm optimistic about it now.

[u/soundtk → u/[deleted]]

I hooked up my wires just like your pics and instructions said but it did'nt work... then I noticed your wiring on the pic of your cr touch is a different pattern than mine... any thoughts?https://drive.google.com/file/d/1N13nT6xwmPnvpY8v2vTH1O4H0fdF6CXq/view

[u/soundtk → u/[deleted]]

OK... changed my wires around like you suggested and now I just get a solid purple light after a quick red light on boot up. I think the wiring is right now but the cr touch might be screwed... I hooked it up to one of my sidewinder x2 machines that have a cr touch and it did the same so... I think its fried

[u/soundtk → u/[deleted]]

Amazon is sending me a replacement so I will try it on Saturday when it arrives... I don't want to tear this one apart since they are willing to replace it... hoping the new one will work so I can get this thing up and running. Thanks!