Remote Processing RPC-210 - Manual (Page 50)

DISPLAY & KEYPAD PORTS BASIC SECTION 11
Page 11-2
Next, display type is set using the CONFIG DISPLAY
command. Functional display types are 0 for the 4 x 40
character display and 1 for the 4 x 20.
CONFIG DISPLAY 0
initializes the display and software for a 4 x 40 character
display.
CON FIG LIN E must be executed before CO NFIG
DISPLAY.
The DISPL AY comm and is used to position and print
information.
DISPLAY (0,2),”Hello”
Starts writing at the first line, 3rd column.
Row and colum n positions begin with number 0. T hus,
(0,0) is the upper left corner. (1, 3) is the second line,
4th column position.
D I S PL A Y m a y b e us e d w i th o ut r ow a n d c o lu m n
positioning information. In that case, printing picks up
wher e the curs or is at.
CLE AR DISP LAY is used to clear the entire display.
CLE AR D ISPL AY L INE clears the line the curs or is
currently at and positions the cursor at the beginning of
that line.
Hiding the cursor
The cursor cannot be hidden. It can be placed out of the
way, usually in the lower right corner For the 4 x 40
display, execute
DISPLAY(3,39)
and for th e 4 x 20 display, execute
DISPLAY (3,19)
USING “UNSUPPORTED” DISPLAYS
Other LC d isplay sizes, such as 1 x 16 o r 2 x 20, will
work. Display pin outs, described below, are different
for differ ent displays. How ever, you should be able to
use the DI SPLA Y CO NN ECT OR P IN OU T table to
make a custom cable.
Displays with one “E” line should be initialized for the 4
x 20 display. The next real issue becomes positioning
the cursor. Position (0,0) and the top row is universal
and you can use the positioning part of the DISPLAY
statement without problem (usually). Accessing other
lines may be tricky. This will depend upon the size of
the display used. The fastest way to determine cursor
position is to try using different DISPLAY (X,Y)
comm ands.
DISPLAY PIN OUTS
Pin outs for a size and type of LC D ar e gener ally
standard. However, pin outs for different display sizes
are not. The m echanical pin out for a 4 x 40 display is
different from a 4 x 20, which is different from a 2 x 20.
S o m e a r e du a l 1 6 pi n, o t he r s a r e du a l 1 4 pi n, a n d s o m e
are single line 14 pin. To further complicate ma tters,
the numbering scheme changes whether you take the
signals from the top or bottom of the display.
Electrically, all of these displays are the same or very
similar.
The following tables are pin outs for J4 on the RPC-210
and the two most popu lar display ty pes. Table 13- 2 is
for a 4 line by 40 character display. Table 13-3 is for
most other displays. This table is usually valid for 14
pin displays.
J4 pin out was optimized for a Optrex 4 x 40 display. A
simple 16 p in IDC connector from J4 to the display is all
that is needed. T he connector fr om this display must
mount on the bottom o f it.
Other 14 pin, dual in line displays m ay also dire ctly
connect using a simple IDC connector. The display
connector mounts on the top side and the ribbon ca ble is
reversed (display pin 1 goes to pin 14 on J5 side).
Connector Orientation
J4 is an open header connector. Pins 1 and 2 are marked
on the board. A s a further aid, a " key" outline is also on
J5.
CONTRAST/ANGLE ADJUSTMENT
Pot R7 is used to adjust display contrast and viewing
angle. The pot is ad justed to 0V at the factory. Its
range is approximately + 5V to -2V, depending upon
display current draw. Adjust R7 for best contrast after
initialization.