User Guide
Operating Modes Overview
Mode 1: Analog Input
Analog input mode takes one or two analog inputs and uses those to set the speed and direction
of the motor. The valid input range is 0v to 5v. This makes the Sabertooth easy control using a
potentiometer, the PWM output of a microcontroller (with an RC filter) or an analog circuit.
Major uses include joystick or foot-pedal controlled vehicles, speed and direction control for
pumps and machines, and analog feedback loops.
Mode 2: R/C Input
R/C input mode takes two standard R/C channels and uses those to set the speed and direction of
the motor. There is an optional timeout setting. When timeout is enabled, the motor driver will
shut down on loss of signal. This is for safety and to prevent the robot from running away should
it encounter interference and should be used if a radio is being used to control the driver. If
timeout is disabled, the motor driver will continue to drive at the commanded speed until another
command is given. This makes the Sabertooth easy to interface to a Basic Stamp or other low-
speed microcontrollers.
Mode 3: Simplified serial.
Simplified serial mode uses TTL level RS-232 serial data to set the speed and direction of the
motor. This is used to interface the Sabertooth to a PC or microcontroller. If using a PC, a level
converter such as a MAX232 chip must be used. A USB-to-TTL serial converter is also a viable
option for the PC. The baud rate is set via DIP switches. Commands are single-byte. There is
also a Slave Select mode which allows the use of multiple Sabertooth 2x12 from a single
microcontroller serial port.
Mode 4: Packetized serial
Packetized serial mode uses TTL level RS-232 serial data to set the speed and direction of the
motor. There is a short packet format consisting of an address byte, a command byte, a data byte
and a 7 bit checksum. The baud rate is set to 9600 by default. See “Baud Rate Selection” later in
this guide for information on changing the baud rate. Address bytes are set via DIP switches. Up
to 8 Sabertooth motor drivers may be ganged together on a single serial line. This makes
packetized serial the preferred method to interface multiple Sabertooths to a PC or laptop.
Because Sabertooth uses the same protocol as our SyRen single motor drivers, both can use used
together from the same serial master.