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Mistakes in project book — Parallax Forums

Mistakes in project book

James CJames C Posts: 3
edited 2007-01-15 18:42 in Learn with BlocklyProp
Hello,

I am a newby at this so please be patient.· I received a Basic Stamp kit from a friend that was purchased at Radio Shack.· I am currently reading chapter 3 and am troubled by mistakes I have found in the book.· I have also noticed that the schematic on the front of the book does not match the bread board rendition.· I spent 30 minutes trying to debug a circuit based on the schematic on page 84 of "What's a Microcontroller?" by Andy Lindsay and found it different than the pictorial rendition on page 85.· I have also found errors in the program, it was missing the "Do" at the start of the loop.

Is anyone familiar with these problems and can I expect more errors in this book.

Thanks,

James C.

Comments

  • Charlie JohnsonCharlie Johnson Posts: 147
    edited 2007-01-13 01:46
    James,

    If you look at page 72, you will see that the pushbutton has 2 pins connected to each side of the pushbutton. Therefore the schematic on the covedr and page 84 is correct. The DO statement is in the first part of the program on page 85. The version of "What's a Microcontroller" I have is version 2.2. If yours is not, you can download the PDF version from the Parallax web site.

    Charlie
  • James CJames C Posts: 3
    edited 2007-01-13 17:52
    Charlie,

    Thanks for your responce.· Based on the page 72 reference you gave, thanks for page reference it helps make things quick, I see a 1 to 4 and a 2 to 3 connection reference.· This seems to be a left to right connect as positioned on the bread board.· If this is true then we have voltage drop resistors on both sides of the switch rather than one side as the schematice denotes on page 84.· Page 85 clearly shows voltage drop resistors on both sides of the push button unit.· Charlie,·I am commited to being a good student here and though I have an extensive background in computers and electronics I try not to presume knowledge in an area I have not directly studied.· I am a beginner at basic programing and at robotic controls.· I am intriuged at the possibilities of this simple but very versatile technologie.· Please know I appreciate input from more skilled individules than myself.· Please correct me if I am wrong about a left, right switch connection·if it is supposed to be a top, bottom configuration or·left to right.· One other thing, the book I am referring to is·revision 2.2.

    Thanks again Charlie for your responce,



    James C.
  • PARPAR Posts: 285
    edited 2007-01-13 21:23
    James C said...

    ·... · Based on the page 72 reference you gave, ..., I see a 1 to 4 and a 2 to 3 connection reference.· This seems to be a left to right connect as positioned on the bread board.· If this is true then we have voltage drop resistors on both sides of the switch rather than one side as the schematice denotes on page 84.· Page 85 clearly shows voltage drop resistors on both sides of the push button unit.·· ... ·Please correct me if I am wrong about a left, right switch connection·if it is supposed to be a top, bottom configuration or·left to right.· One other thing, the book I am referring to is·revision 2.2.

    ...

    Figure 3-1, right image ("part drawing"), shows pins 1 and 4 at the "top" left and right --respectively--·of the switch. Pins 2 and 3 are shown at the "bottom" left and right --respectively-- of the switch.

    Pins 1 and 4 are connected to each other internally to the switch. Ditto for pins 2 and 3.

    The switch's button, when pressed, will connect both "top" pins to both "bottom" pins. I.e., pins 1 and 4 get connected to pins 2 and 3, or to put it another way, the "top" of the switch gets connected to the "bottom" of the switch. Or, you can say that pins 1 and 4 are connected to one switch terminal, and pins 2 and 3 are connected to the other switch terminal.

    The switch is a single, two-terminal·switch (as explained on p.71), not two two-terminal switches. The reason the switch has four legs (pins) instead of just two is simply for mechanical stability, as explained on pp.71-72.

    When installing/wiring the switch, you need to know which is "top" and which is "bottom".

    So, in figs. 3-3, 3-5, 3-6, for example, those are all "top" to "bottom" switchings: unpressed --> no connection between top and bottom; pressed --> connects top to bottom.

    PAR



    Post Edited (PAR) : 1/13/2007 9:31:49 PM GMT
  • James CJames C Posts: 3
    edited 2007-01-14 20:11
    Thanks,

    I have checked the book again and am encoraged to find myself mistaken.· An up down connect of the respective left and right pins does infact match its·schematic.· Thanks for the input, I expect I may have some questions about basic and the stamp controller.· This is a great resource.

    Thanks again,

    James.
  • Steph LindsaySteph Lindsay Posts: 767
    edited 2007-01-15 18:42
    Hello James,

    As you discovered, the generous forum members here are glad to help out newcomers, and Andy keeps an eye on this forum when he can as well.· Maybe the book was correct in this instance, but there actually are a few errors you will run into.· I keep an updated errata·sheet on the book's product page on our·website:

    http://www.parallax.com/detail.asp?product_id=28123

    If you find any other errors, please feel free to email me at editor@parallax.com

    Newbies make great reviewers, because they don't fill in gaps or errors with thier own knowlege!· I hope you have fun with the kit.

    -Stephanie Lindsay

    Editor, Parallax Inc.
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