User Manual

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 SyRen easy to control using a
potentiometer, the PWM output of a microcontroller (with an R-C 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. There is also a Diff-Drive mixing mode which
takes two analog inputs for “tank style” steering.
Mode 2: R/C Input
R/C input mode takes one or two standard R/C channels and uses those to set the speed and
direction of the motor. R/C mode can be set up as a single input driver for robots and vehicles
that have steering wheels, as well as a 2-input mode for differential drive steering. This combines
the ease of use of a dual motor driver with the flexibility of a single motor driver. 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 SyRen 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 SyRen to a PC or microcontroller. If using a PC, a level
converter such as a MAX232 chip must be used. The baud rate is set via DIP switches.
Commands are single-byte, with 0 representing full reverse and 255 representing full forward.
There is also a Slave Select mode which allows the use of multiple motors 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. SyRen 50 is set to 9600 baud from the factory. To change this, please
navigate to the Packet serial section in this document and locate the commands page. Address
bytes are set via dip switches. Up to 8 SyRen motor drivers may be ganged together on a single
serial line. This makes packetized serial the preferred method to interface multiple SyRens to a
PC or laptop.