Playing with the Apple PowerMac backlight
An article in arstechnica.com teaches how to use the backlight of the keyboard in the powerbook as a CPU load monitor. The code is simple, and you try to have some fun with your mac.
According to the page:
It took some trial and error to get the numbers from the CPU usage to correspond properly with the number needed to set the brightness of the backlight. What I did find is that the function host_processor_info is not granular enough to give accurate readings under a second. My keyboard was flashing when the update time was 0.1 seconds. I might try to look to see if there is a better what to get the numbers I want.
I also want to make the brightness fade instead of jump like the program does now. It should be relatively easy to do: Amit showed how in Figure 6 of his article. I want to tinker with the range of the brightness of the keyboard as well, to make it a little more obvious. Another idea I had was to change how bright the min and max were depending on the readings of the Ambient Light Sensors: brighter during high light levels, and lower during less.