Understanding Signals with the PropScope - Chapter 4: Pulse Width Modulation (Draft Copy)
Andy Lindsay (Parallax)
Posts: 1,919
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The latest version of Understanding Signals with the PropScope is now published in both print and PDF.
You can download the full PDF textbook from:
www.parallax.com/go/PropScope
Thanks to all our reviewers for their input!
The latest version of Understanding Signals with the PropScope is now published in both print and PDF.
You can download the full PDF textbook from:
www.parallax.com/go/PropScope
Thanks to all our reviewers for their input!
Comments
"and it also examines how to utilize the PropScope’s features to measure these signals"
"utilize" has always seemed to me to be a word people (okay, my students...) throw in to try to sound more high-fallutin', and it fails at that. In addition, the rest of the document's tone is very informal, notably in the use of "it's" instead of "it is" (and other contractions). I assume you're shooting for informal, so "utilize" is pretty jarring.
P. 128 "The radio transmitters in these systems codes the joystick’s position into bursts of radio activity."
Should be "The radio transmitters in these systems code the joystick’s position into bursts of radio activity."· ("code" instead of "codes")
P. 148 - In the diagram, it looks like the word "infrared" is in normal type while the rest of that label is in italics.
P. 154 - "Like an 8-bit binary number can contain a number in the 0 to 255 range, a 12-bit binary number can contain a number in the 0 to 4095 range."
It'd be more grammatical to say "Just as an 8-bit binary number can contain a number in the...".
Also perhaps that should specify "...can contain a decimal number in the 0 to 255 range".
P. 160 "In contrast, TV remote communication protocols tend to leave more room for variations in the pulse durations that represent binary-1s and binary-0s."
As earlier, it might be more clear if the hyphens were removed, as they could be interpreted as minus signs ("that represent binary 1s and binary 0s"). In fact a little later in the page you do exactly that. And then further down, you use "ones" and "zeros". How about a consistent standard? I'd go with either "1s and 0s" or "ones and zeros".
Post Edited (sylvie369) : 7/28/2010 6:25:04 PM GMT
This is great material! Thank you. All has been duly noted and queued for the next edit. I should have the Chapter 5 draft up tonight. After that, I'll be taking a 1 week break, and will resume posting chapters 6-9 starting either Thursday, 8/5 or Friday, 8/6.
Andy
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Andy Lindsay
Education Department
Parallax, Inc.
Hopefully I'll be through the chapters you already have up by the time you're back - it'll be a great way to spend my time while listening to Brewers games.
I downloaded the PropScope software and installed it this afternoon. I assume that the software linked to from the PropScope product page is the current version.
Have a nice trip.
Post Edited (sylvie369) : 7/28/2010 10:06:04 PM GMT
The version of the PropScope software for testing with the book is available from the Latest PropScope Software discussion. It is now a sticky thread in this Forum. There are two live links on there right now. Make sure to get v1.07.
Andy
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Andy Lindsay
Education Department
Parallax, Inc.
Post Edited (Andy Lindsay (Parallax)) : 7/29/2010 12:10:20 AM GMT
Paul
Incidentally, I get·a cryptic·error message when I start the PropScope software, and look at the probe settings (in the "Manage Probes" menu item) when I don't have a PropScope attached. It's a minor thing, since presumably you care most about the software working when a PropScope IS attached. But it's cryptic. Maybe an error trap to display a less frightening message window?
Post Edited (sylvie369) : 7/29/2010 3:46:20 AM GMT
Nice catch! I agree; the message does look somewhat cryptic and potentially intimidating. Also, folks trying Chapter 1 before the hardware arrives are likely to encounter it since one of the activities guides them through setting their probes to 1x.
Andy
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Andy Lindsay
Education Department
Parallax, Inc.