New Micros NMIY-0031, Руководство пользователя

Страница: 39 / 188

2 / 2 6 / 2 0 0 2 2 : 0 6 P M 2 / 2 6 / 2 0 0 2 3 9
N M I Y - 0 0 3 1 P R O G R A M S E G M E N T S
Program Segments
The following examples are provided to display the process of communicating with the LCD and
key pad option. The code is written to be first instructive and secondly well written in the usual
sense. We assume that the user can produce well-written code after reading and understanding
the examples of using board facilities.
MONITOR
The following example will clear the LCD, set the display for blinking cursor on, and display the
message:
“HELLO WORLD!”
The monitor ignores embedded spaces in a command line. When the last numeral on each line is
entered the monitor will execute the command and give a new line at the control terminal. Note
that each line starts with an upper case “O” and all subsequent characters are valid hexadecimal
characters (all upper case) or spaces. The CAPS LOCK key is preferred. Spaces are not required
by the Monitor, but are allowed and included for readability. The comments on each line are
rejected by the monitor and should not be entered.
O 38 FFF8 ; Set 2 line display and 5x7 dot format
O 38 FFF8 ; Set 2 line display and 5x7 dot format
O 06 FFF8 ; Entry mode: cursor moves to right, no display shift
O 0F FFF8 ; Set display and blinking cursor on
O 01 FFF8 ; Clear Display
O 80 FFF8 ; Set cursor to left end of line one
O 22 FFF9 ; Display ‘ ” ’
O 48 FFF9 ; Display “H”
O 45 FFF9 ; Display “E”
O 4C FFF9 ; Display “L”
O 4C FFF9 ; Display “L”
O 4F FFF9 ; Display “O”
O 20 FFF9 ; Display “ “
O 57 FFF9 ; Display “W”
O 4F FFF9 ; Display “O”
O 52 FFF9 ; Display “R”
O 4C FFF9 ; Display “L”
O 44 FFF9 ; Display “D”
O 21 FFF9 ; Display “!”
O 22 FFF9 ; Display ‘ “ ‘
When the entry process is completed, you should see:
“HELLO WORLD!”_
on the LCD with a blinking cursor on the right end.
Keypad access is quite different. Reading is accomplished in a two step process. First, a column
value is written to the latch, then the latch is read. Successive column values are written and read
until a non-FF value is returned. This column is the one with a key press. The non-FF value
returned identifies the row value. The following example and explanation illustrates this: