WeeklyPerformer

You need to First send command M502 to clear EEPROM and reset to factory settings, then Make sure to save those changes with M500. once reset you will be able to flash the firmware. Remember to measure your Z offset, run a G29, then SAVE all those values with M500 again so they persist in the EEPROM. Hope this helps.

Sorry, i don't speak french. But it appears that this printer is quite popular among my french friends across the pond. I've compiled and modified the stock Longer LK4 Pro/Alfawise U30 Pro Marlin firmware to be compatible with BLtouch V3.1 (newest revision). Simply use the mount linked in the post, compile, and upload to your machine! NOTE: All probe offsets hard coded in the firmware were measured with that mount. If you use a different mount your offset settings will likely change! Always measure if you are unsure! You will then need to set your M851 Z offset in Arduino Serial monitor (See Page 5 of this PDF: https://locxess.de/3d/BLTouch_Anleitung_englisch.pdf). Make sure to do an M500 to save all settings including G29 if you'd like to use M420 S1 in your start GCode. I've cut out most of the settings for the U20 Pro to save some on board storage space. 5 X 5 grid is default but can be changed if you want higher resolution. That's the beauty of Marlin! Download (Original post): https://www.reddit.com/r/Longer3d/comments/f1t0b1/lk4_pro_alfawise_u30_pro_bltouch_enabled_marlin/ I hope this helps some of you to streamline your BLTouch installation and WOW what an upgrade to print quality!!!! If you haven't calibrated your extruder steps for this machine you really should as well. This in combination with the BLTouch will give you AMAZING prints. Good luck and HAPPY PRINTING!!