Product Specifications

Option 1: Standard Simplified Serial
Mode
Serial data is sent to input S1. The baud rate is selected
with switches 4 and 5. Commands are sent as single bytes.
Sending a value of 1-127 will command motor 1 Sending a
value of 128-255 will command motor 2. Sending a value
of 0 will shut down both motors.
Option 2: Simplified Serial with Slave
Select
This mode is used when it is desirable to have multiple
Sabertooth motor drivers running from the same serial
transmitter, but you do not wish to use packetized serial. A
digital signal (0v or 5v) is fed to the S2 input. This is
controlled by the host microcontroller. If the signal on S2 is
logic high (5v) when the serial command is sent, then the driver will change to the new speed. If
the signal on S2 is not high when the command is sent, then command will be ignored. Pseudo-
code demonstrating this is shown below. After sending the signal, allow about 50 us before
commanding the Slave Select line to a logic LOW to allow time for processing. A hookup
diagram and example pseudo-code are shown in Figures 6.2 and 6.3.
//set controller 1’s speed
Output_High (S2 pin on controller 1)
USART_TX(controller 1 speed, 0 to
255)
Delay_us(50)
Output_Low (S2 pin on controller 1)
//set controller 2’s speed
Output_High (S2 pin on controller 2)
USART_TX(controller 2 speed, 0 to
255)
Delay_us(50)
Output_Low (S2 pin on controller 2)
Figure 6.2: Hookup for Slave Select Figure 6.3: Pseudocode for Slave Select
Standard Simplified Serial
Simplified Serial with Slave Select