Picture of Wall Following Robot Using 555 Timer
 This robot is also in the Robot Contest for the age 12-18 category.

In this instructable I will write out the basic ideas which I used to make a wall following robot without any microcontroller. The robot in these instructions was originally used in the Trinity Firefighting contest , and was supposed to be the first robot (that I know of) to compete without a microcontroller. However it did not successfully blow out the candle.

Recently, my friend informed me of the 555 contest and encouraged me to enter the robot. However, I do not have time to remake the robot frame and whatnot, so I will give this instructable using the original frame with the firefighting parts removed. Also, I used some specific parts in this build like Vex motors, and I haven't tested if one can substitute in other continuous rotation servos and have the same effect. As a result of all this, I will not tell you how to replicate my robot, but instead give the ideas (and circuit) that its based on and leave it to you to determine the frame and parts to use in your build.

 Also, this is my first instructable. I will update it or redo it with proper instructions if I have time later maybe.

Hello guys this wll follower robot is cool

you can have a loook to concept of wall follower robot in detail here
Can you please post a video of how does it work?
hasn0life (author)  vinayakniraj00022 years ago
Ptr_V_24 years ago
Nice ible, nicely written, innovative and detailed.
HarveyH444 years ago
I think there is a slight flaw in your schematic. The signal from the IR receiver goes to the opamp, the output of the opamp, feeds both halves of the 556. Both motors should basically do the same thing, only difference would be from variance in part tolerances. The trim pots should cover that. This bot, doesn't exactly move in a straight line, does it?

I have watch the video, I use FireFox, which doesn't like YouTube for some reason...
hasn0life (author)  HarveyH444 years ago
I tried to explain this in the last section. The motors do the same thing, but because one of them is upside down, it moves backwards, so the robot wants to turn. You have to bias the motors using the trimpots so that they both move forward when the distance sensor sees a certain distance.

The robot can move in a straight line if its following a straight wall and you calibrate it in a specific way. In my video I adjusted it to do wide turns because I didn't have much time to tune it. It can actually run even better than that and not do the twitching in the video.