28123 Parallax Inc, 28123 Datasheet - Page 49

• 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

Yellow-Violet-Brown = 4-7-0.
Introducing the LED
A diode is a one-way current valve, and a light emitting diode (LED) emits light when
current passes through it. Unlike the color codes on a resistor, the color of the LED
usually just tells you what color it will glow when current passes through it. The
important markings on an LED are contained in its shape. Since an LED is a one-way
current valve, you have to make sure to connect it the right way, or it won’t work as
intended.
Figure 2-4 shows an LED’s schematic symbol and part drawing. An LED has two
terminals. One is called the anode, and the other is called the cathode. In this activity,
you will have to build the LED into a circuit, paying attention to make sure the leads
connected to the anode and cathode are connected to the circuit properly. On the part
drawing, the anode lead is labeled with the plus-sign (+). On the schematic symbol, the
anode is the wide part of the triangle. In the part drawing, the cathode lead is the
unlabeled pin, and on the schematic symbol, the cathode is the line across the point of the
triangle.
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•
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The first stripe is yellow, which means the leftmost digit is a 4.
The second stripe is violet, which means the next digit is a 7.
The third stripe is brown. Since brown is 1, it means add one zero to the right of
the first two digits.
LED
Figure 2-4
LED Part Drawing
and Schematic
Symbol
Part Drawing (above)
and schematic symbol
(below).
The LED’s part
drawings in later
pictures will have a +
next to the anode leg.