28122 Parallax Inc, 28122 Datasheet - Page 150

• 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

Testing the Potentiometer Circuit
How the Potentiometer Circuit Works
The total resistance in your test circuit is 220 Ω plus the resistance between the A and W
terminals of the potentiometer. This value could be anywhere from 0 to 10 kΩ. As you
LED
Vss
√
√
Turn the potentiometer clockwise until it reaches its mechanical limit shown in
Figure 5-6.
Gradually rotate the potentiometer counterclockwise to the positions shown in
Figure 5-6 (b), (c), (d), (e), and (f) noting the how brightly the LED glows at
each position.
Handle with care: If your potentiometer will not turn this far, do not try to force it. Just turn
it until it reaches its mechanical limit; otherwise, it might break.
Vdd
(a)
(b)
nc
220
Pot
10
kΩ
Ω
P15
P14
P13
P12
P11
P10
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
(c)
(d)
X2
X3
Vdd
Vin
(e)
(f)
Vss
+
Figure 5-6
Potentiometer Input Shaft
(a) through (f) show the
potentiometer’s wiper
terminal set to different
positions.
Figure 5-5
Potentiometer-LED
Test Circuit