Matrix Orbital LK204-25 - Manual (Page 22)

22
Commands
1. Communications
1.1. Changing the I2C
Slave Address
Dec
Hex
ASCII 254 51
FE 33
■ 3
Address
Address
Address
Immediately changes the I2C write address. Only even values are permitted as the next odd address will become
the read address. Default is 80.
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. Not available in I2C. Baud rate can be temporarily forced to 19200 by a
manual override.
Speed 1 byte, valid settings shown below
Table 20: Accepted Baud Rate Values
Rate 1200 2400 4800 9600 19200 28800 38400 57600 115200
Speed 83 41 207 103 51 34 25 16 8
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. Speed must be a whole number between 977 and
153800. Due to rounding, error increases with baud rate, actual baud must be within 3% of desired baud to ensure
accurate communication. Not available in I2C. Can be temporarily forced to 19200 by a manual override.
Speed 2 bytes, calculations shown below, standard crystal speed is 16MHz
( )
Equation 1: Speed Byte Calculation
( ( ))
Equation 2: Actual Baud Rate Calculation
| |
Equation 3: Baud Rate Error Calculation
1.4. Transmission
Protocol Select
Dec
Hex 254 160
FE A0
Protocol
Protocol
Selects the protocol used for data transmission from the display. Data transmission to the display is not affected.
Must be set to the protocol in use to receive data correctly.
Protocol 1 byte, 1 for Serial (RS232/RS422/TTL/USB) or 0 for I2C