The MakerBot Motherboard is a shield for the Arduino MEGA. This board will be the main controller for our 3D printer, controlling the stepper drivers, monitoring the limit switches, and an SD slot for storage. The interface connector could be connected to an interface board for controlling the machine without a computer. To control the extruders, it comes with 2 rs485 ports and can support up to five RS485 ports. It accepts a standard ATX header for power. For more detailed info go here

The motherboard is capable of driving up to five different stepper drivers at the same time. These motors are sometimes referred to as an axis (singular) or axes (plural). The headers for the stepper drivers are labeled X, Y, Z, A, and B.

1 N/C unused and not connected.
2 GND Connected to ground on the motherboard.
3 STEP Step pin. Sends a pulse to the stepper driver when it needs to take a step.
4 DIR Direction pin. HIGH = forward, LOW = reverse. Can be configured in software.
5 ENABLE Enable pin. LOW = enabled, HIGH = disabled. Enables the stepper driver. Software definable
6 N/C unused and not connected.

It has headers for 6 endstop cables (X+/–, Y+/–, Z+/–) and an e-stop switch. This header is where they are plugged into.

1 5V This pin provides 5V to the endstop switch.
2 GND connected to ground on the motherboard.
3 GND connected to ground on the motherboard.
4 SIGNAL connected to a digital input pin on the motherboard. LOW = activated, HIGH = normal. can be configured in software.