The scripts utilizes old steppermotor from floppydisk drive that I wanted to make work with raspberry pi 3.
The physical stuff is pretty DIY, I used old 9-pin internal motherboard cable from old computer and the pins from internal usb-module.
I used a PCB circuit with 12v power source and 4 NPN transistors that are connected to RP3, those NPN's are cutting grounds
from the motor. There's two programs, one can be used for demonstrating a CNC machine as for given inputs directly, other program can be used to pass directions via cmdline.
The pins arranged in script equal into this sequence array
StepPins = [27,22,23,24]
Seq[0] = [1,0,0,0]
Seq[1] = [0,1,0,0]
Seq[2] = [0,0,1,0]
Seq[3] = [0,0,0,1] - GPIO27 = seq0 = yellow on motor
- GPIO22 = seq1 = white
- GPIO23 = seq2 = blue
- GPIO24 = seq3 = red
2 browns are +12V
This is how the motor seems to work for me when controlling motor via cutting ground.
You need to have python3 installed.
python3 main.py