Fearless Experiments With Microcomputers by Gregg Maryniak

Author:Gregg Maryniak [Maryniak, Gregg]
Language: eng
Format: azw3
Tags: -
Publisher: BookBaby
Published: 2017-03-15T04:00:00+00:00

As you will learn, these colors are used to list the resistance in Ohms with the last digit used to signify a multiplier so that you can code hundreds, thousands or millions or Ohms. In addition, an additional band is used to specify how precise the resistor is. Two additional colors (Gold and Silver) are sometimes used if the resistor is precise to within tolerances of 5% or 10% respectively.

What Is Happening as This Circuit and Program Work Together?

Because you want exponential brightness, you will double the number that you input to the pwmout command by adding the contents of register w0 to itself in each pass of the program loop. Let the program do this until the register reaches 256, at which point you will start all over with your doublings. In response to the numbers doubling in the register, the pwmout command is sending pulses of increasing width to pin C.2. As a result, the LED is turned on for a greater fraction of time and we perceive increased brightness.

Wouldn’t it be cool if you could actually see the pulses fed into the LED? Since the pulses happen very rapidly (too rapidly for your brain and eyes to deal with them), you would need some kind of device to freeze the picture to capture what is happening. Such devices are called oscilloscopes. “Scope” means to see, and “oscillate” means to move back and forth (usually quickly). Oscilloscopes let us see rapid oscillations. By the way, don’t confuse this word with osculate, which means to kiss!

If you are online, you can see a touch command-triggered version of this circuit in action, connected to an oscilloscope here: https://www.youtube.com/watch?v=TDcV8mHVj9M

If you’re offline, the following still images from this very short video will give you the idea.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.