28123 Parallax Inc, 28123 Datasheet - Page 276

• 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

Digital Pot Controlled Transistor Parts
(1) Transistor – 2N3904
(2) Resistors – 100 kΩ (brown-black-yellow)
(1) LED – any color
(1) Digital potentiometer – AD5220
Building the Digital Potentiometer Circuit
Figure 9-6 shows a circuit schematic with the digital potentiometer used in place of a
manual potentiometer, and Figure 9-7 shows a wiring diagram for the circuit. The
BASIC Stamp can control the digital potentiometer by issuing control signals to P5 and
P6.
Vdd
6. B1 – The potentiometer’s B terminal.
7. CS – The chip select pin. Apply a high signal to this pin, and the chip ignores all
8. Vdd – Connect to +5 V, which is Vdd on the Board of Education and BASIC
P6
P5
√
control signals sent to CLK and U/D. Apply a low signal to this pin, and it acts
on any control signals it receives.
Stamp HomeWork Board.
The AD5220 Part Datasheet:
www.analog.com. Enter AD5220 into the Search field on Analog Devices’ home page, and
click the Search button. Click the Data Sheets link. Click the link that reads “AD5220:
Increment/Decrement Digital Potentiometer Datasheet”.
Build the circuit shown in Figure 9-6 and Figure 9-7.
1
2
3
4
CLK
U/D
A1
GND
AD5220
Vss
Vdd
W1
CS
B1
6
5
8
7
Vdd
To see the part datasheet for the AD5220: Go to
100 k
100 k
Ω
Ω
Vdd
Vss
Figure 9-6
Digital Potentiometer
Controlled Transistor
Circuit Schematic