28123 Parallax Inc, 28123 Datasheet - Page 286

• 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

P1. Use the digital potentiometer circuit from Figure 9-6, p. 269 and the
Vdd
UdPin
ClkPin
counter
LOW UdPin
FOR counter = 0 TO 128
NEXT
photoresistor circuit from Figure 7-2, p. 191.
This solution is based on TerminalControlledDigitalPot.bs2, except instead of
being controlled by typing in the Debug Terminal, it is controlled by reading the
photoresistor. A subroutine,
using
becomes the new tap setting, and the original program does the work to set the
tap. The parts of the original program that ask for input from the Debug
Terminal were deleted, including the
' What's a Microcontroller - Ch9Prj01_PhotoControlledDigitalPot.bs2
' Update digital pot's tap based on photoresistor reading
' {$STAMP BS2}
' {$PBASIC 2.5}
DEBUG "Program Running!"
' -----[ Declarations and Initialization]------------------------------
UdPin
ClkPin
PhotoPin
DelayPulses
DelayReader
PULSOUT ClkPin,5
PAUSE 1
P6
P5
RCTIME
2
3
4
1
CLK
U/D
A1
GND
AD5220
as shown in Chapter 5. The reading from the photoresistor
CON
CON
VAR
CON
CON
CON
CON
CON
Vss
Vdd
W1
CS
B1
8
7
6
5
Vdd
5
6
Byte
5
6
2
10
2000
100
100
Read_Photoresistor
kΩ
kΩ
Vdd
Get_New_Tap_Setting
Vss
P2
' Set values of I/O pins
' connected to CLK and U/D.
' Set U/D pin for Down.
' Set tap to lowest position.
' Set values of I/O pins
' connected to CLK and U/D.
' Photoresistor on pin P2
' Delay to observe LED fade.
' Counter for FOR...NEXT.
220
, reads the photoresistor
Ω
Vss
subroutine.
0.01 µF