I have been meaning to design a robot which basically avoids obstacles. So I decided to make a IR sensor and brightness sensor. Attached is a written step by step process of designing a IR sensor that would be remain turned on when no obstacle is in front and will turn off when an obstacle is detected. The blue LED is a general purpose Led to visually show how the circuit performs.

I have covered the IR led and the IR phototransistor with heat shrink tubing to make it less susceptible to ambient light.

This procedure will come in hand if someone else also decided to make one.

Please comment

 

Hello,

I do not see the attachment.
Did you forget it?

Bertus

 

it should be attached now

 

When, not if, you get into microcontrollers, you can do error correction a different way. Here is an old link to noise correction using the 12F/12C series PIC.

http://users.frii.com/dlc/robotics/projects/botproj.htm

Scroll to the 12C508 project. There are also useful links therein to the Dallas group.

I have been using that method in a device for several years. It works indoors, outside, bright sunlight, overcast, etc.

John

 

i was thinking about it..and have been reading up on the subject. So far, I think the Arduino Uno seems like a good start off point.. I think i should start a new thread for this topic

 

When, not if, you get into microcontrollers, you can do error correction a different way. Here is an old link to noise correction using the 12F/12C series PIC.

http://users.frii.com/dlc/robotics/projects/botproj.htm

Scroll to the 12C508 project. There are also useful links therein to the Dallas group.

I have been using that method in a device for several years. It works indoors, outside, bright sunlight, overcast, etc.

John

That is a great link!

I usually add something similar to the whisker/contact sensors in addition to IR and/or sonar, sometimes things appear out of nowhere (kid's hands, cats, paws, etc), and miss the IR sensors. Other things that are too small to catch, such as thin chair legs when off axis/in a turn will be caught by the whiskers and stop it before it gets scratched.

Remember to add a reverse direction option, obstacle avoidance robots have a tendency of getting stuck somewhere that they need to back up.

Lastly, a beeper or "SOS" LED to go off when the program is out of solutions for whatever spot it got into. This helps you to program better and learn what is going on.

For starting out, it doesn't matter if you use an Arduino or Picaxe, the languages are a bit different, but the concept is the same.

To keep costs down, you'll eventually start using just the AVR (Arduino) or PIC (PicAxe, Basic Stamp) IC and a programmer, doing the program design and compiling on a PC. This changes the cost of a robot control from $30-$50 down to under $10 each, after the one time cost of the programmer.