Sensor and Switch

Sensor/switch connections

Each axis of the STEP400 and STEP800 has a HOME connector which allows for you to plug-in some form of limit switch or equivalent sensor. Additionally, the STEP400 has LIMIT inputs for each axis in addition to the HOME inputs.


Since the stepper motor cannot track its own position, a dedicated sensor is required to return to the home position on boot-up. It is directly connected to the motor driver IC and can be used for position management. The pin is pulled up to 3v3 (3.3V) inside the driver IC.


STEP400 Only

As stated above, the STEP400 has an additional LIMIT switch input that can be used to limit the operational range of each motor. You can configure these inputs to halt the motor, or to be used as another input for another purpose. Like the HOME input, this input is also pulled up to 3v3.

Connection Terminals

We use the XA series connectors from JST (J.S.T.MFG.CO., LTD.). For compatible connectors, please refer to the following:

Product name Model number Remarks
(Reference) PCB Post B03B-XASK-1 (LF)(SN) Header mounted on the PCB
Housing XAP-03V-1 Plastic housing
Contact BXA-001T-P0.6 Crimp contact inserted into the housing

Pin assignments

The pin assignments for both inputs are the same. The pin number is printed on the housing.

Pin number Function
2 Sensor/switch input
3 5V output

The driver responds when the input falls from HIGH (3v3) to LOW (0V). Therefore, the switch must behave as "normally open".

For more information, please refer to Homing and Position Management.

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