28123 Parallax Inc, 28123 Datasheet - Page 155

• Manufacturer Part Number: 28123
• Description: TEXT WHAT'S A MICROCONTROLLER
• Manufacturer: Parallax Inc
• Type: Programmingr

Specifications of 28123

• Style: Book
• Title: What's a Microcontroller?
• Contents: Whats a Microcontroller? Text
• Product: Microcontroller Accessories
• Core Processor: PIC16C57c
• Flash: 128 Bytes
• Operating Supply Voltage: 9 V
• Board Size: 31 mm x 16 mm
• Lead Free Status / RoHS Status: Not applicable / Not applicable

LOOP UNTIL IN7 = 0
DEBUG CR, CR, CR, "The RC decay time was ",
END
How PolledRcTimer.bs2 Works
Two variables are declared. The
the capacitor to discharge through R
while the capacitor is charging.
The command
successive measurements.
“Capacitor charging…”
down while the capacitor is charging. As the capacitor charges, the voltage across its
terminals increases toward anywhere between 2.5 and 4.9 V (depending on the value of
R
A message announces when the decay starts getting polled.
In order to let the capacitor discharge itself through the R
from
sense high or low signals. As soon as the I/O pin releases the circuit, the capacitor
i
).
DEBUG ? IN7
DEBUG DEC5 timeCounter, CR, CRSRUP, CRSRUP
HIGH
DEC timeCounter, CR,
"tenths of a second.", CR, CR
timeCounter
counter
DEBUG CLS
HIGH 7
DEBUG "Capacitor Charging...", CR
FOR counter = 5 TO 0
NEXT
DEBUG CR, CR, "Measure decay time now!", CR, CR
PAUSE 1000
DEBUG DEC2 counter, CR, CRSRUP
to
INPUT
DEBUG CLS
. As an input, the I/O pin, has no effect on the circuit, but it can
clears the Debug Terminal so that it doesn’t get cluttered with
VAR
VAR
HIGH 7
message is displayed. After that, a
timeCounter
sets P7 high and starts charging the capacitor, then a
Word
Nib
i
.
The
counter
variable is used to track how long it takes
variable is used to count down
i
resistor, the I/O pin is changed
FOR…NEXT
loop counts