Matrix Orbital DD-DB1 LCD/VFD Dev Board - Manual (Page 19)

Commands
1. Communications
1.1.Changing the I2C
Slave Address
Dec
Hex
ASCII 254 51
FE 33
3 ■
Address
Address
Address
Immediately changes the I 2 C write address.
Address 1 byte, even value
1.2.Changing the
Baud Rate
Dec
Hex
ASCII
254 57
FE 39
9 ■
Speed
Speed
Speed
Immediately changes the baud rate. Can be temporarily forced to 19200 with manual override.
Speed 1 byte, valid settings shown below
Rate 1200 2400 4800 9600 19200 28800 38400 57600
Speed 83 41 207 103 51 34 25 16
1.3.Setting a Non-
Standard Baud Rate
Dec
Hex
254 164
FE A4
Speed
Speed
Immediately changes the baud rate to a non-standard value. Range is 977 to 153800. Speed must be a whole number.
Due to rounding, error increases with baud rate, actual baud must be within 3% of desired baud to ensure accurate
communication. Baud rate can be temporarily forced to 19200 by a manual override.
Speed 2 byte, calculations shown below
Speed =
CrystalSpeed
 8× DesiredBaud 
− 1 ActualBaud =
CrystalSpeed
 8× Speed1
∣ DesiredBaud − ActualBaud∣
DesiredBaud
 0.03
1.4.Transmission
Protocol Select
Dec
Hex 254 160
FE A0
Protocol
Protocol
Selects the protocol used for data transmission to the host. Data transmission from the host is not affected. Must be set
to the protocol in use to receive data correctly.
Protocol 1 byte, 1 for Serial (RS232/TTL/USB) or 0 for I 2 C
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