My students are making a line following robot, and they asked me about the best line following sensor.
My reply was what I use (the output from a CNY70 is hooked up to the AVRs ADC, so I can use a nice autocalibration algorythm (will post someday)), and how they could use it,then I told them the simple analog comparator way, where you have an external analog comparator, but you get faster results in a digital (0 - 1) form. Then they asked me, if it was possible to hook up the CNY70 directly to the pin of the procesor. I advised against it.
Which of these aproaches would you use?
A: External comparator:
+Simple, yes/no results
-A lot of extra components
B: Internal ADC:
+No extra components, software configurable
-Slower, a bit more complex
C: See it as a digital output:
+Simple, no extra parts
-You cannot use it on all surfaces, nor can you calibrate it in any way.
PS: This poll was made only out of interest as to what the other freaks use.