122-28176 Parallax Inc, 122-28176 Datasheet - Page 14

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

While flowcharting has fallen out of fashion in many programming circles due to the
advent of object-oriented programming (PBASIC used by the BASIC Stamp is
procedural language), it is still an excellent tool when planning program flow.
Flowcharting is particularly useful in process control because it can be used to visually
represent the steps and decisions required to perform control of the system.
Take the everyday task of preparing the temperature of the shower before stepping into it.
In pseudocode, or English statements outlining the steps to take, this is how we would
proceed:
While it’s not too difficult to read through these steps to see what actions should be
taken, as a program or procedure becomes more complex it becomes more difficult to
visualize the flow of the process and what actions and branches are needed. For example,
how much more complex would the flow be if the hot water valve becomes fully open
before the optimum temperature is reached?
As complexity increases, a flowchart makes it easier to visualize how the process will
flow. Take a look at the flowchart in Figure 1-2, which describes the same process as the
pseudocode above.
1. Turn on cold water.
2. Turn on hot water.
3. Wait 3 seconds for temperature to stabilize.
4. Test water temperature.
5. If too hot, then:
6. If too cold, then:
7. If just right then get in shower.
a. Turn hot water down.
b. Go back to step 3.
a. Turn hot water up.
b. Go back to step 3.