28123 Parallax Inc, 28123 Datasheet - Page 275

• 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

Introducing the Digital Potentiometer
Figure 9-5 shows a pin map of the digital potentiometer you will use in this activity. This
chip has 8 pins, four on each side that are spaced to make it easy to plug into a
breadboard (1/10 inch apart). The manufacturer places a reference notch on the plastic
case so that you can tell the difference between pin 1 and pin 5. The reference notch is a
small half-circle in the chip’s case. You can use this notch as a reference for the pin
numbers on the chip. The pin numbers on the chip count upwards, counterclockwise
from the reference notch.
Here is a summary of each of the AD5220’s pins and functions:
1. CLK – The pin that receives clock pulses (low-high-low signals) to move the
2. U/D – The pin that receives a high signal to make the wiper (W1) terminal move
3. A1 – The potentiometer’s A terminal.
4. GND – The ground connection. The ground on the Board of Education and
5. W1 – The potentiometer’s wiper (W) terminal.
wiper terminal.
towards A1, and a low signal to make it move towards B1. This pin just sets the
direction, the wiper terminal doesn’t actually move until a pulse (a low – high –
low signal) is sent to the CLK pin.
BASIC Stamp HomeWork Board is the Vss terminal.
Part Substitutions: It is sometimes necessary for Parallax to make a part substitution. The
part will function the same, but the label on it may be different. If you find that the digital
potentiometer included in your What’s a Microcontroller Parts Kit is not labeled AD5220, rest
assured that it will still work the same way and perform correctly in this activity.
3
4
1
2
Reference
CLK
U/D
A1
GND
Notch
AD5220
Vdd
W1
CS
B1
8
7
6
5
Figure 9-5
AD5220 Pin Map
Use the reference
notch to make
sure you have the
AD5220 right-side-
up when building it
into your circuit on
the breadboard.