Data Sheet

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ROBOT.HEADtoTOE
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8.4SERIALPACKETIZEDMODE
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In Packetized Serial mode, Enhanced SmartDrive40 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 Enhanced SmartDrive40 can be              
connectedtogethertoasinglemicrocontrollerUARTTxpin.
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Besides that, the Enhanced SmartDrive40 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, Enhanced SmartDrive40 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.
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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. Enhanced SmartDrive40 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.
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Packetized Serial mode is selected by setting SW1, SW2 and SW3 to 1 (Up). SW4 – SW6                
areusedtoselecttheaddress.
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InputMode
SW1SW3
111
PacketizedSerialMode
UARTAddress
SW4SW6
000111
07
0OFF 1ON XDon’tCare
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Apacketconsistsof4bytesandtheformatisshowninthefollowingtable.
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Byte
Name
Value(Decimal)
Description
1
Header
85
Toindicatethestartofpacket.
2
Address
07
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.
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
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CreatedbyCytronTechnologiesSdn.Bhd.–AllRightsReserved 22
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