What sensor configuration do/would you use?

Go To Last Post
3 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

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.

Thanks,

David

PS: This poll was made only out of interest as to what the other freaks use.

Attachment(s): 

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I would use 4 sensors. 3 for following and 1 for calibration. 3 sensors to the analogue comparator inputs (3 different comps of course) and the compare value comes from the calibration sensor that is placed on the background area. add a jumper to change if it needs to follow a light line or a dark one. easy ;)

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Bloody hell - I got into the BBC thirty years ago partly on the strength of a line follower: two OP12 (or maybe something-59?) and a couple of opamps.

Who needs micros?