28122 Parallax Inc, 28122 Datasheet - Page 53

• Manufacturer Part Number: 28122
• Description: KIT WHAT'S A MICRO:PARTS ONLY
• Manufacturer: Parallax Inc

Specifications of 28122

• Accessory Type: Parts Kit
• Product: Microcontroller Accessories
• Core Processor: PIC16C57c
• Flash: 128 Bytes
• Operating Supply Voltage: 9 V
• Board Size: 31 mm x 16 mm
• For Use With/related Products: Board of Education Full Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

How the LED Test Circuit Works
The Vdd and Vss terminals supply electrical pressure in the same way that a battery
would. The Vdd sockets are like the battery’s positive terminal, and the Vss sockets are
like the battery’s negative terminal. Figure 2-7 shows how applying electrical pressure to
a circuit using a battery causes electrons to flow through it. This flow of electrons is
called electric current, or often just current. Electric current is limited by the resistor.
This current is what causes the diode to emit light.
√
√
√
Double check to make sure you built your circuit exactly as shown in Figure 2-
6.
If you are using a What’s a Microcontroller kit that somebody used before you,
the LED may be damaged, so try a different one.
If you are in a lab class, check with your instructor.
Still stuck? If you don’t have an instructor or friend who can help, you can always check
with the Stamps in Class discussion group. The first pages of this book has Internet Access
information on where to find the Stamps in Class discussion group. If the group is unable to
help you solve the problem, you can contact the Parallax Technical Support department by
following the Support link at www.parallax.com.
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N
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Figure 2-7
LED On Circuit Electron
Flow
The minus signs with
the circles around them
are used to show
electrons flowing from
the battery’s negative
terminal to its positive
terminal.