28029 Parallax Inc, 28029 Datasheet - Page 293

• 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

ACTIVITY #3: TWO-AXIS BAR GRAPH FOR ACCELEROMETER TILT
This activity develops a two axis bar graph that is useful for graphically displaying the
accelerometer's tilt measurements.
Parts and Equipment
Use the circuit from Chapter 3, Activity #2, page 71.
Vertical Bar Graph Custom Characters
The
different custom vertical bar characters. Figure 7-3 shows how each bar character
corresponds to a value.
The custom character definitions in Figure 7-3 follow a sequence that relates directly to
the values they represent, so the definitions can be calculated as needed rather than being
stored in EEPROM.
eliminating 16 definitions will save 128 bytes of program memory.
The
value
the
or white.
rowMap
Def_Vert_Bar_Char
Def_Vert_Bar_Char
variable defines which one of the 0 to 15 characters will be displayed. Each bit in
Def_Vert_Bar_Char:
SEROUT LcdPin, T9600,
rowMap = %1111111100000000 >> (value & %1111)
variable determines whether one of the rows in the custom character is black
[Define + custChar]
Since each custom character definition takes up eight bytes,
subroutine in the next example program defines any one of 16
subroutine defines the characters shown in Figure 7-3. The
Chapter 7: LCD Bar Graphs for Distance and Tilt · Page 281
Figure 7-3
Vertical Character Bar
Graph Values