Remote Technologies RPC-320 - Manual (Page 32)

DISPLAY PORT SECTION 8
Page 8-1 RPC-320
Figure 8-1 Display interface
INTRODUCTION
RPBASIC-52 and the RP C-320 interface to a variety of
displays:
VF (vacuum florescent) character
LCD (liquid crystal) character
LCD gr aphics
Character display sizes range from four lines by 20
characters to four lines by 40 characters. The graphics
display supports 160 x 128 pixels. Remote Processing
supplies these displays with appropr iate cables. A
contrast a djustment fo r LC D char acter disp lays is built
into the card.
If a display is not used, this port may be used for general
purpose digital I/O. P ort A and part of port B from an
82C55 are available. See CONNE CTOR D ISPLAY PIN
OUT below for ava ilable lines.
The cable length to a display depends upon the amount
of current it requires. A significant amount of voltage
drop occurs with a long cable. V acuum florescent and
LCD graphics cables should b e less than 2 fee t. A
charac ter LC D display c able should be less than 5 feet.
CONNECTING DISPLAYS
The display port is designed to supply all the lines
necessar y for V F and L CD displays. A custom cable
connects the RPC-320 to the display.
Displays purchased from Remote Processing include a
cable. You simply connect the 20 pin connector to the
RPC-320 L CD display port and the other end into the
display.
A d d it io n al po w e r w i r in g is u su a ll y r e q ui r ed f or L C D
graphic and VF charac ter displays. This infor mation is
included with the display. Information content is display
dependent. Below is general information on both.
Graphic displays require additional voltages not
generated on the RPC-320. These must be supplied
externally. An external contrast adjustment may be
necessary. Y ou may be able to connect these through
screw term inal block P5.
VF c haracte r displays r equire + 5 volts and gr ound to
connector P5. This may in the form of external wires
from the main power connector on the board or power
supply.
Additional information for commands m entioned in the
following text are found in the RPBASIC-52 Software
Supplem ent in this man ual.
WRITING TO THE DISPLAY
The display type must first be set using the CON FIG
DISPLAY command. T he DISPLAY com mand is used
to print information.
PROGRAMMING EXAMPLE
The example below is for a four line by 20 character
LCD display. Even though DISPL AY statements do not
end with a comma (, ), a < cr> < lf> sequence is not
sent. Use C R to force a return to the beginning of the
line. A CR does not scroll characters on a display. You
must position the cursor to the next line.
10 CONFIG DISPLAY 1
20 STRING 200,30
30 $(0) = "Hello world"
40 DISPLAY (1,2),$(0)