nanoDLP

so from your sketch it would appear you have one of these

and this is the corresponding schematic

A stepper driver draws way too much current to be powered from the Raspi directly. Added to which the stepper driver needs at least 12VDC to drive a Nema 17.

I would normally use a 12VDC power supply Then use a buck converter to power the Raspi and wire the stepper driver directly to the PSU ( usually with an in line fuse)

Then a similar buck / boost converter with current limiting for the LED array

I couldn't see/ open your "mosfet_wiring.tif " ??

Hi. An 8 mm pitch sounds much too big for any lead screw I've ever seen. Are you sure that's correct.

Its your control boards firmware that needs to know the steps per mm as well

Import a profile from somebody then try a dry run ( no resin in vat) when its working you can edit the various sections to suit your particular resin

SHould indeed give a finer resolution.  All it means is that 12800 steps will equal 1 rotation.
If for example, you use a lead screw with a 2mm pitch, 12800 steps will give you 2mm of Z travel.

Not sure exactly with direct control but normally a "steps/mm" ( steps per millimeter) is required as a configuration input So using the example above you would input 6400 as being the steps required to travel Z 1mm

Hi . Yes i understand your intent but the only stepper driver they have on the BG website has 3 pins on the right hand side not 4 pins like your photo ( KLMN) and the resolution of the photo isnt good enough to read the PCB screen print.
Reference https://www.banggood.com/A4988-DRV8825- … rehouse=CN
Im wondering on your board what the 4th pin is for ? 
The others are
E ( enable) (pin16 on raspi)
D ( direction ) (pin 15 on raspi)
S ( step) ( pin 22 on raspi)

AS for the step stick module, it can be A4988 or DRV8825 but not both !?  it is very important which you have because of the orientation when you plug them in is different. Be careful

Your best bet is probably to find somebody who has a D7 ( i don't) and more importantly using the same firmware as you and ask them to share a resin profile with you. This will contain the previously mentioned before and after layer Gcode. Then just edit that to suit the resin you plan to use.

Check your router to see what IP address has been assigned to Nano DLP.  Under DHCP it may have been assigned a different IP address than your previous sessions.  Most routers will allow you to reserve a specific IP address for a device by using its IMAC number

To the best of my knowledge the end stop position ( max or min) are configured in the control board firmware Not in Nanodlp .... As are the steps per mm, homing direction etc etc

You should be able to just drive the Easy driver from the Raspi3 ( 3 signals>> enable / step/ direction )

The easy driver will need its own power source and be sure to link the GND of the raspi to the GND of the easydriver power source

In theory and based on the fact that a lot of SLA / DLP printers use FDM control boards, Configure the firmware and make a thermostat that then connects to the "filament out" sensor on the control board. Just an idea

Are you sure your model is oriented at Z zero ??