We are currently getting it completed for us to post it under the 2.5A stepper driver page. However here is the correct wiring procedure.
First: Wire the 24V power supply to the 2.5A driver, by wiring +V on the power supply to 12-24V on the driver. Next wire the COM on the power supply to Ground(GND) on the 2.5A driver. GND on the driver will also go to the GND on the USB board, for specific axis. (additional 3-4 wires connected to ground will be needed for the other axes as well).
Second: Wire the USB board to the driver(one driver per axis on the USB board):
CP on the driver will go to CP on the desired axis on the USB board.
CW on the driver will go to CW on the desired axis on the USB board.
5V will go to the VCC pin on the keyboard jog pins on the USB board (check schematic here: https://buildyourcnc.com/item/electronicsAndMotors-electronic-component-USB-Controller-Breakout#prettyPhoto/2/).
GND on the USB board to GND on the driver. (as specified in step 1).
EN is not used.
I would recommend that you crimp the VCC pin to a wire which could be split for the other axes as well, each driver will need 5V.
Third: Wire the stepper motor to the driver, (using either the Nema 23 100-oz or the Nema 17 62-oz stepper motors, the wiring will be the same. For the Nema 23 the yellow and white is not connected.)
Black to A1
Green to A2
Red to B1
Blue to B2
Fourth: Repeat steps 1-3 for each driver/motor per axis.
Mention: Remember that GND on the driver will also go to the GND on the USB board for specific axis, and VCC pin on the USB board (keyboard jog) will go to 5V on all drivers for each axes as well, each driver will need 5V!
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Is there a complete wiring diagram for the Medium Combo Kit with the usb board? Your USB tutorial does not cover the modular 2.5a drivers. https://buildyourcnc.com/item/electronicsAndMotors-3axis-100-elcombo