28123 Parallax Inc, 28123 Datasheet - Page 70

• 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 Bi-Color LED
The bi-color LED’s schematic symbol and part drawing are shown in Figure 2-16.
The bi-color LED is really just two LEDs in one package. Figure 2-17 shows how you
can apply voltage in one direction and the LED will glow red. By disconnecting the LED
and plugging it back in reversed, the LED will then glow green. As with the other LEDs,
if you connect both terminals of the circuit to Vss, the LED will not emit light.
Red
1
2
Green
LED-
bicolor
1
2
Figure 2-15
Bi-color LED in a
Security Device
When the door is
locked, this bi-color
LED glows red.
When the door is
unlocked by an
electronic key with
the right code, the
LED turns green.
Figure 2-16
Bi-color LED
Schematic symbol (left)
and part drawing (right).