FLSUN QQ-S Optical EndStop

Replacement of mechanical limit switches (ENDSTOP) with optical ones. Main advantages of optical limit switches:
- high repeatability of the result
- no bounce
- wear resistance

Would need:
- 3 optical sensors (as in the photo) obstacles, with a comparator and a Schmitt trigger;
- 3-4 m. three-core wire (0.2-0.3 m2)
- 3 triple Dupont and HU connectors

When assembling, pay attention - the side cover-posts have the wrong radius and after installing new mounts with the sensor they do not fit into place. Solution - bend them with your hands, a little)

Relevant for firmware 2.3
After assembly, you need to flash your printer, you need to make the following edits in the firmware configuration file (find the following directives and change their meaning):

> Z_MAX_LENGTH 362 (measure the real distance from the surface to the nozzle with a ruler when the head is raised to the top position)
> ENDSTOP_X_MAX_INVERTING 1
> ENDSTOP_Y_MAX_INVERTING 1
> ENDSTOP_Z_MAX_INVERTING 1