Line Following Tank Without A Microcontroller

This line following tank uses analog circuitry to sense where a dark line is and adjust its course. Despite the opening paragraph on the schematic page (which looks to be leftover from a past project writeup) this circuit relies on a set of transistors for motor control. [Chris] does a great job of explaining the setup in detail; it boils down to a phototransistor detecting reflected light and flipping which motor is running based on what is detected. A couple of potentiometers are included to tune up the accuracy of the circuit. There’s a short clip of the treaded-terror making a loop around the track after the break.

This is another great way to try your hand at analog circuitry. Once you’ve built the body (tank or otherwise) and line tracking circuit it can be repurposed by swapping out the brains for your next project.


23 thoughts on “Line Following Tank Without A Microcontroller

  1. Just a quick glance at this article makes me think of the BEAM robotics from years ago. I’m glad to see that people still make things (including robotics), without using microcontrollers (as simple as they can make things). Nice.

  2. reminds me of the robotic kits i would make when i was a kid that were line following using all passive and analog devices
    personally non-microcontroller robotics is old news to me they have been around longer than microcontroller robotics
    but for thoes who have not seen these robotics try it! … if done right they almost never mess up XD

  3. wonderful!
    the best write up, i have seen in a long time. great pictuers, good explanations. not just the usual look-whative-done-video, this is something one can try with kids on a rainy sunday.
    all my annoyance about instructables -this makes up for everything.

  4. I always wonder why Myth Busters don’t use a similar setup instead of their clunky RC controllers. Half their car stunts are fubar’d because they can’t hit the ramp/other car/etc straight on.

  5. This was probably the most fun project I did in first year compsci. We started off with a basic breadboard, sensors, and wires, and had to make the car successfully follow a line. then we swapped out our circuitry for a microcontroller, and had to reproduce the same effect with assembler.

    If you got the code working, there were bonus points for the most efficient and smooth line tracking – they had a bunch of pre-prepared lines designed to throw your car off the scent.

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