Data Sheet

The STEP and DIR lines are pulled down by default. The driver takes one step whenever it sees

a rising edge on the STEP pin, and the direction of the step is specified by the DIR pin. See the

DRV8825 datasheet [https://www.pololu.com/file/download/drv8825.pdf?file_id=0J590] (1MB pdf) for detailed

specifications of the STEP/DIR interface on the Tic T825, or see the DRV8834 datasheet

[https://www.pololu.com/file/download/drv8834.pdf?file_id=0J617] (2MB pdf) for detailed specifications of the

STEP/DIR interface on the Tic T834.

In STEP/DIR mode, the Tic’s USB, serial, and I2C interfaces can still be used to set the driver’s current

limit, decay mode, and step mode, or to de-energize the driver.

Alternatively, when the Tic’s control mode is set to anything other than “STEP/DIR”, you can use the

STEP and DIR pins as outputs to control an external stepper motor driver. However, you will still need

to supply power to the Tic’s VIN pin, or else the Tic will report a “Low VIN” error and not attempt to

drive the motor.

4. Setting up the controller Page 55 of 150