Pololu Maestro User Manual
Page 36
The USB Dual Port serial mode.
The USB Chained serial mode.
The UART serial mode.
The Maestro can be configured to be in one of three basic serial modes:
USB Dual Port: In this mode, the Command Port can
be used to send commands to the Maestro and receive
responses from it. The baud rate you set in your
terminal program when opening the Command Port is
irrelevant. The TTL Port can be used to send bytes on
the TX line and receive bytes on the RX line. The
baud rate you set in your terminal program when
opening the TTL Port determines the baud rate used
to receive and send bytes on RX and TX. This allows
your computer to control the Maestro and
simultaneously use the RX and TX lines as a general purpose serial port that can communicate with other types of
TTL serial devices.
USB Chained: In this mode, the Command Port
is used to both transmit bytes on the TX line and
send commands to the Maestro. The Maestro’s
responses to those commands will be sent to the
Command Port but not the TX line. Bytes
received on the RX line will be sent to the
Command Port but will not be interpreted as
command bytes by the Maestro. The baud rate
you set in your terminal program when opening
the Command Port determines the baud rate used
to receive and send bytes on RX and TX. The
TTL Port is not used. This mode allows a single COM port on your computer to control multiple Maestros, or a
Maestro and other devices that have a compatible protocol.
UART: In this mode, the TX and RX lines can be
used to send commands to the Maestro and receive
responses from it. Any byte received on RX will be
sent to the Command Port, but bytes sent from the
Command Port will be ignored. The TTL Port is not
used. The baud rate on TX and RX can either be
automatically detected by the Maestro when a 0xAA
byte is received on RX, or it can be set to a fixed
value specified in bits per second (bps). This mode
allows you to control the Maestro (and send bytes to
a serial program on the computer) using a microcontroller or other TTL serial device.
Other serial settings:
Enable CRC: If checked, the Maestro will require a cyclic redundancy check (CRC) byte at the end of every serial
command except the Mini SSC command (see
).
Device Number: This is the device number (0–127) that is used to address this device in Pololu Protocol commands.
This setting is useful when using the Maestro with other devices in a daisy-chained configuration (see
).
Pololu Maestro Servo Controller User's Guide
© 2001–2014 Pololu Corporation
5. Serial Interface
Page 36 of 73