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Matrix Orbital LCD0821 Legacy User Manual

Page 18

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LCD0821 rev 2

18

Custom characters occupy a 5 x 8 pixel matrix. Built-in characters are 5 x 7: the bottom row of pixels is
normally reserved for the underline cursor. The underline cursor should be turned off if the bottom row of
pixels forms part of a custom character.

The characters are defined by issuing the command 254 78 [c] followed by 8 bytes to define the character.
[c] is the character number (0x00 to 0x07). The 8 bytes are mapped as shown below:

MSB

LSB

* * * 1 2 3 4 5 Data

Byte

1

*

*

*

6

7

8

9

10 Data Byte 2

*

*

* 11 12 13

14 15 Data Byte 3

*

*

* 16 17 18

19 20 Data Byte 4

*

*

* 21 22 23

24 25 Data Byte 5

*

*

* 26 27 28

29 30 Data Byte 6

*

*

* 31 32 33

34 35 Data Byte 7

*

*

* 36 37 38

39 40 Data Byte 8

A "1" bit indicates an on (black) pixel, a "0" bit indicates an off (clear) pixel.

Once defined, a character is displayed simply by issuing a value (0x00 to 0x07) corresponding to the
character number. The character will be laid out as follows: