28122 Parallax Inc, 28122 Datasheet - Page 201

• 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

ACTIVITY #2: GRAPHING LIGHT MEASUREMENTS
Factories often have to monitor many sensor inputs to make sure the products they make
turn out right. From light levels in a greenhouse to fluid levels in an oil refinery to
temperature levels in a nuclear reactor, the people responsible for controlling these levels
often rely on graphs of the sensor measurements to get the information they need.
Introducing Stamp Plot Lite
Figure 7-4 shows Stamp Plot Lite software graphing RC-time measurements sent by the
BASIC Stamp. The line shown in Figure 7-4 is much easier to understand than the 250
RC-time measurements that were used to plot that line. Viewing the graph from left to
right, the RC-time measurements gradually get larger and then suddenly drop off. Since
RC-time measurements get larger when the light levels decrease and smaller when they
increase, the graph tells a story. It looks like the light level being measured declined
gradually, and then it suddenly increased again.
This graph could depict any number of scenarios to the technician reading it. Perhaps a
microcontroller in a greenhouse switched on the artificial lights after the sunlight dropped
below a certain level. Perhaps a system of motors and gears that maintains a solar
panel’s position for maximum sunlight exposure just readjusted the panel’s position after
√
Before you move on to the next activity, return the circuit to the original one
shown in Figure 7-2 by removing the 0.1 µF capacitor and replacing it with the
0.01 µF capacitor.
Figure 7-4
Stamp Plot Lite
Graphing
Measured Light
Levels