Data Sheet

levels. You can try connecting the device’s TX line directly to the Tic’s RX line; this will usually work,

but the input signal on the RX pin must reach at least 4 V to be guaranteed to be read as high. If

you want to read data from the Tic, you will need to consider how to connect the Tic’s TX line to your

device’s RX line. If your device’s RX line is 5V tolerant, meaning that it can accept a 5 V output being

applied directly to it, then you should be able to connect the Tic’s TX line directly to your device’s RX

line. If your device’s RX line is not 5V tolerant, you will need to a use a level shifter—a separate board

or chip that can convert 5 V signals down to 3.3 V. A voltage divider made with two resistors would

work too.

Whenever connecting devices, remember to wire the grounds together, and ensure that

each device is properly powered. Unpowered devices with a TTL serial port can turn on

or partially on, drawing power from the serial line, which means that extra care must be

taken when turning power off and on to reset the devices.

Note: You must use an inverter and level shifter such as a MAX232 or a Pololu 23201a

Serial Adapter [https://www.pololu.com/product/126] if you want to interface an RS-232 device

with the Tic. Connecting an RS-232 device directly to the Tic can permanently damage it.

If you are using an Arduino or Arduino-compatible board, you should now try running the

SerialSpeedControl example that comes with the Tic Arduino library. The library’s README

[https://github.com/pololu/tic-arduino] has information about how to get started and which pins of the

Arduino to use. If you are using a different kind of microcontroller board, you will need to find or write

code to control the Tic on your platform. If you are writing your own code, we recommend that you

first learn how to send and receive serial bytes on your platform, and then use the SerialSpeedControl

example as a reference. You should also refer to the sections in this guide about the Tic’s commands

(Section 8) and serial protocol (Section 9).

If your connections and code are OK, you should now see the Tic’s stepper motor moving back and

forth. If the stepper motor is not moving, you should check all of your connections and solder joints (if

applicable). You should make sure that the Tic and your device are configured to use the same baud

rate. The Tic uses 9600 bits per second by default. You should also check the “Status” tab of the Tic

Control Center to see if any errors are being reported.

The SerialSpeedControl example only writes data to the Tic, so it does not test your connection to

the Tic’s TX line. If you want to read data from the Tic, you should now try the SerialPositionControl

example, which reads the current position of the stepper motor from the Tic.

4. Setting up the controller Page 34 of 150