122-28176 Parallax Inc, 122-28176 Datasheet - Page 20

• 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

Code Discussion
As you read through the program, you can see that the coding that corresponds to the
various elements of the flowchart are well highlighted using comments.
The pushbutton switch is active-low, meaning that its value is 0 when pressed. This is
because the pushbutton is pulled up to Vdd when not pressed and brought to Vss when
pressed. (This will be explored more in Chapter 3.)
Note that the flowchart block for 'Measure Photo Resistor' takes 3 lines of code. The
flowchart just describes the process and is not intended to be a line-by-line description.
This flowchart could be used for coding or designing any number of devices in any
number of languages.
Looking it Up: The PBASIC commands and programming techniques used here were
introduced in What’s a Microcontroller?, the recommended prerequisite to Process Control.
If you would like a refresher about specific program elements, you can look it up quickly in
the BASIC Stamp Editor’s Help file. Or, refer to the BASIC Stamp Syntax and Reference
Manual, available for purchase or free download from www.parallax.com.
Figure 1-5
BASIC Stamp
Editor’s Help
Files
The PBASIC
Syntax Guide
places
information and
examples for all
commands at
your fingertips.