28029 Parallax Inc, 28029 Datasheet - Page 196

• Manufacturer Part Number: 28029
• Description: KIT PARTS SMART SENSORS W/TEXT
• Manufacturer: Parallax Inc

Specifications of 28029

• Accessory Type: Parts Kit
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: BASIC Stamp® or Javelin Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 28029PAR

Page 184 · Smart Sensors and Applications
Take a look at Figure 5-9. Notice that six ordered pairs were entered into the Debug
Terminal, but there is only one asterisk, and it corresponds with the last pair that was
entered. That's because the program used here makes the old asterisk disappear by taking
the old x, y coordinates to look up the background character from EEPROM, and then
displaying it with
a
programs.
The program used to create Figure 5-9 combines the
from EepromBackgroundDisplay.bs2 with the asterisk plotting and location tracking
technique from PlotXYGraphRecall.bs2. This combination allows us to redraw the
background character over the old asterisk with this code:
DEBUG
IF (x <> xold) AND (y <> yold) THEN
ENDIF
command with the current x, y coordinates as did our previous example
index = (14 * yOld) + xOld + 1
READ index, character
DEBUG CRSRXY, xOld, yOld, character
DEBUG
. To make the asterisk appear at its new location, it simply uses
DATA
' Check if asterisk moved
' Background character address
' Get background character
' Display background character
-defined background technique
Figure 5-9
Display using EEPROM
Background Refresh