Data Sheet

For details about how the input scaling works, see Section 5.2.

4.10. Setting up analog speed control

This section explains how to set up the Tic to read an analog input and use that signal to control the

speed of the stepper motor.

If you have not done so already, you should follow the instructions in Section 4.3 to configure and

test your stepper motor. Next, with the system unpowered, connect your analog signal to the Tic as

described below.

If you are using a potentiometer to make the analog signal, you should connect the potentiometer’s

wiper to SDA/AN and connect the other two ends to GND and SCL, as shown in the diagram below.

In analog mode, the SCL line is driven high (5 V) to power the potentiometer (note that the SCL pin is

protected by a 470 Ω series resistor, so it will not be damaged by inadvertent shorts to ground).

If you are using something other than a potentiometer to generate the analog signal, make sure that

the ground node of that device is connected to a GND pin on the Tic, and that the analog signal

from that device is connected to the Tic’s SDA/AN line. The Tic’s analog input can only accept signals

between 0 V and 5 V with respect to GND; signals outside of this range could damage the Tic.

Now connect the Tic to your computer via USB. In the Tic Control Center software, set the Tic’s control

mode to “Analog speed” and click “Apply settings”. In the “Scaling” box, click “Learn…” to start the

Input Setup Wizard. The wizard will help you measure the neutral, maximum, and minimum positions

of your analog signal. When the wizard is finished, it will set five of the input scaling parameters

(input maximum, input neutral max, input neutral min, input minimum, and invert input direction)

appropriately so that the neutral analog signal gets mapped to a velocity of 0, the maximum analog

signal gets mapped to the target maximum, and the minimum analog signal gets mapped to the target

4. Setting up the controller Page 47 of 150