28123 Parallax Inc, 28123 Datasheet - Page 173

• 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

Chapter #6: Digital Display
THE EVERY-DAY DIGITAL DISPLAY
Figure 6-1 shows a display on the front of an oven door. When the oven is not in use, it
displays the time. When the oven is in use, it displays the oven’s timer, cooking settings,
and it flashes on and off at the same time an alarm sounds to let you know the food is
done. A microcontroller inside the oven door monitors the pushbuttons and updates the
display. It also monitors sensors inside the oven and switches devices that turn the
heating elements on and off.
Each of the three digits in Figure 6-1 is called a 7-segment display. In this chapter, you
will program the BASIC Stamp to display numbers and letters on a 7-segment display.
WHAT’S A 7-SEGMENT DISPLAY?
A 7-segment display is rectangular block of 7 lines of equal length that can be lit
selectively to display digits and some letters. A very common form is the 7-segment LED
display, a package with a rectangular block of 7 LEDs. Figure 6-2 shows a part drawing
of the 7-segment LED display you will use in this chapter’s activities. It has one
additional LED, a dot that can be used as a decimal point. Each of the segments (A
through G) and the dot contains a separate LED, which can be controlled individually.
Most of the pins have a number along with a label that corresponds with one of the LED
segments. Pin 5 is labeled DP, which stands for decimal point. Pins 3 and 8 are labeled
“common cathode”, and they will be explained when the schematic for this part is
introduced.
Figure 6-1
Digital Clock 7-Segment
Display on Oven Door