28123 Parallax Inc, 28123 Datasheet - Page 48

• 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

Resistors like the ones we are using in this activity have colored stripes that tell you what
their resistance values are. There is a different color combination for each resistance
value. For example, the color code for the 470 Ω resistor is yellow-violet-brown.
There may be a fourth stripe that indicates the resistor’s tolerance. Tolerance is measured
in percent, and it tells how far off the part’s true resistance might be from the labeled
resistance. The fourth stripe could be gold (5%), silver (10%) or no stripe (20%). For the
activities in this book, a resistor’s tolerance does not matter, but its value does.
Each color bar that tells you the resistor’s value corresponds to a digit, and these
colors/digits are listed in Table 2-1. Figure 2-3 shows how to use each color bar with the
table to determine the value of a resistor.
Here is an example that shows how Table 2-1 and Figure 2-3 can be used to figure out a
resistor value by proving that yellow-violet-brown is really 470 Ω:
Table 2-1:
Resistor Color
Code Values
Digit
0
1
2
3
4
5
6
7
8
9
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
470
Ω
Yellow
First Digit
Violet
Brown
Gold
Silver
or
Blank
Second Digit
Figure 2-2
470 Ω Resistor Part
Drawing
Schematic symbol (left)
and Part Drawing (right)
Number of Zeros
Tolerance
Code
Figure 2-3
Resistor Color
Codes