RAMPS 1.4, Marlin, Zmin Switch & Proximity Sensor

Ok, I've consulted the google machine, and have come up short. I've got a K8200 that has been completely modified. I'm running the hardware on a RAMPS 1.4 with the current version of Marlin firmware. I have added a proximity sensor mounted next to the hotend, and can make auto bed leveling successfully work. The problem is that I use a thick mirror plate over the heatbed, so the proximity sensor can only sense the bed in locations that i've placed silver tape around the edges for bed leveling purposes. I have accidentally hit Z home twice now and crashed my print head into the bed. Each time the z motor twists the anti-wobble connector between the motor and the axis rod rendering it useless.

So i've put the z stop switch back in place to prevent this. I've got the proximity sensor working on the zmax RAMPS connector, but cant get the configuration.h to utilize both at the same time. I'd like to use the end stop for safety (and maybe homing) then trigger autolevel before i start a print (and ignore the zmin). Is what i'm trying to accomplish even possible? and if anyone has a similar setup could you share your config?

Thanks!

The ability to use both a Z_MIN_ENSTOP and a Z_PROBE is supported in RC-3 (Release Candidate #3). It is a little tricky to configure. Be sure to read the directions and work carefully. If you are going to use that branch, you are best off using: https://github.com/MarlinFirmware/Marlin/tree/RCBugFix That is the same thing but with some carefully thought out bug fixes.

With that said, if I was trying to do what you are saying you want, I would use https://github.com/MarlinFirmware/MarlinDev/tree/Jan20 That has a number of nice improvements to the Z-Probe and Z_MIN_ENDSTOP and the two work nicer together. The only downside, is you will need to read the Wiki over at MarlinDev to get the tools configured to build the firmware. [This branch is where I'm doing all my work. It is very stable and cleaned up.]