Nano3D
Direct Control
You can use NanoDLP without using any kind of additional micro-controller. NanoDLP will generate pulse, even though it is much simpler to setup and easier to use. Due to uneven pulse generation using this method, it is much better to use Shield instead.
Following parameters are not useful if you are going to use Shield.
The Raspberry Pi GPIO should be wired to the equivalent PIN on stepper motor drivers such as A4988 and DRV8825 directly.
GPIO
Raspberry Pi GPIO has voltage limitation. A voltages near 3.3V. is interpreted as a logic high and a voltage near zero volts is a logic zero.
For more details about GPIO wiring, visit Raspberry Pi pinout page.
Endstop
Endstop switch must be placed on top of z-axis. This switch will be used for automatic z-axis calibration and position recovery. Endstop switch output should be high and when touched it should be low.
Also resetting may happens depend on settings if the end-stop switch triggered.
Direction pin
High means upward movement and low means downward movement.
Enable pin
If your driver has enable pin (such as DRV8825), wiring to Raspberry Pi provides a way to prevent any unwanted movements during Raspberry Pi bootup process. After bootup this pin output will be set to logical High and Low based on “Enable Pin State” setting.
Microstepping
Microstepping value for Stepper driver, if you do not use any microstepping, put 1 as value.
2 for half step 4 for 1/4 16 for 1/16 32 for 1/32
Pitch
Distance travelled on each turn of Leadscrew