Cytron SmartDriveDuo Smart Dual Channel 10A Motor Driver : Manual : Page 20

ROBOT . HEAD to TOE

Product User’s Manual – MDDS10

8.4 SERIAL PACKETIZED MODE

In Packetized Serial mode, SmartDriveDuo-10 is controlled by using the UART interface.

DIG1 pin is the UART Rx pin. DIG2, AN1 and AN2 pins are not used in this mode. To

control the motor, data sent to the driver must be in 4 bytes packet format which includes a

header, address, command and checksum. Up to 8 units of SmartDriveDuo-10 can be

connected together to a single microcontroller UART Tx pin.

Besides that, the SmartDriveDuo-10 also incorporates an Auto-Baud feature in Packetized

Serial mode. When the driver is first powered up, the host microcontroller must send a header

byte (Decimal 85 or hex 55) once to the driver. The driver will then calculate the baud rate

automatically based on this byte. After that, SmartDriveDuo-10 is ready to read full packet (4

bytes) and the baud rate cannot be changed without power recycle (power off and on) or reset

button.

NOTE:

1. When the driver is powered up and waiting for the header byte, the error LED will

blink and indicate that there is input error.

2. SmartDriveDuo-10 may take up to 500ms to start up after power is applied. Sending

the header byte for auto baud during this time period may cause undesirable results.

Please allow one-second delay between applying power and sending the header byte.

Packetized Serial mode is selected by setting SW1, SW2 and SW3 to 1 (Up). SW4 – SW6

are used to select the address.

Input Mode

SW1 - SW3

111

Packetized Serial Mode

UART Address

SW4 - SW6

000 - 111

0 - 7

0 - OFF 1 - ON X - Don’t Care

A packet consists of 4 bytes and the format is shown in the following table.

Byte

Name

Value (Decimal)

Description

1

Header

85

To indicate the start of packet.

2

Channel &

Address

Channel: Bit 3

Address: Bit 2 - 0

Used to identify the driver when multiple units are connected

together. The address bits (bit 2 - 0) must match the address

configured with the DIP switch. Bit 3 represent which motor

to be controlled, 0 for motor LEFT and 1 for motor RIGHT.

3

Command

0 – 255

Value 127 stops the motor, 0 is full reverse and 255 is full

forward.

4

Checksum

0 – 255

The value for checksum must be the result of

Header + Address + Command