BLTouch on Anycubic I3 Mega (Version 2 with ultrabase) - Needs to be 8 bit version
What you need is a BLTouch probe (Affiliate link, consider buying from here if you want to give some support to this: http://s.click.aliexpress.com/e/Qr72FaY) - Cheapest price I could find, and was the one I used to code the firmware with.
Make this mount in ABS/High heat tolerant filament, and install it as per his instructions (as far away as possible from hotend) using m3 screws and nutshttps://www.thingiverse.com/thing:2824005
Credit to Petrzmax
Download the PDF for clear instructions and images on how to install the BLTouch to the anycubic I3 Mega
Link to firmware using Marlin 1.1.8 with ABL enabled. Firmware also uses Z-endstop for G28 command to level bed, and G29 uses BLTouch to measure bed surface.
Flash this firmware: https://www.dropbox.com/sh/igl7ny8afryajq1/AADOUzbKtO8QfU5q04TysJdna?dl=0
It will use BLTouch 5 x 5 point grid
Original firmware based off derhopp and beaving - uses latest marlin build
And usual disclaimer do this at your own risk, but works well for me
PDF of instructions attached to this group
Link to facebook discussion group:https://www.facebook.com/groups/122568018406103/permalink/164536894209215/
For those of you who want to play with the firmware, the uncompiled version is here:https://www.dropbox.com/sh/stfyx6pmew2cwir/AABJQFy3XqVwAQRFrmpxkupia?dl=0