Remote Technologies RPC-320 Connecting Displays, Writing to the Display, Programming Example

DISPLAY PORT

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.

Figure 8-1 Display interface

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.

SECTION 8

Additional power wiring is usually required for LCD 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)

Page 8-1 RPC-320