This instructable will use three photoresistors (light dependent resistors) and an Arduino to control the motion of a robot. Any common robot chassis can be used for the robot. The light sensors will be mounted on the left side, right side and front of the robot. When light of sufficient intensity falls on a sensor, the robot will respond with a left turn, right turn or forward movement, corresponding to the location of the sensor that is activated. The instructable will also pass along some electronics tips that I have found useful and, hopefully, will prove useful to others.

Step 1: List of Materials

List of Materials:

3x Light Dependent Resistors


3x 250K trimmers (potentiometers)


3x Three pin sensor cables


1x Duemilanove or compatible Arduino board http://www.freetronics.com/collections/arduino/products/eleven#.UzImtdhOWM8

1x DFRobot motor shield

http://www.dfrobot.com/index.php?route=product/product&filter_name=motor shield&product_id=69#.UzInGthOWM8

1x Arduino proto shield


1x Robot Chassis


2x 4”x6” Proto boards


Various standoffs and hardware. A good kit can be found at


The standoffs used in this instructable are from a Trossen Robotics robot kit. The standoffs and hardware are also sold individually



1x 6AA battery holder


1x 9V battery holder with barrel plug


Finally, we will need some male and female headers



<p>Hey I need some help with project. i'll pay good ... ? i want to make a rc plane that has a object recognition and following that object (car, other rc plane, ...) </p><p>whatever you need i'll provide</p>
<p>can you send a circuit diagram</p>
<p>You listed a 9V batt holder in the parts list, but no mention of it was made in the assembly instructions. May we assume it was used to power the Arduino board? Of course the Arduino could also be powered by the 6xAA battery pack, but the electrical noise generated by brush-type DC motors would probably not make the microcontroller too happy. Is that why you used the 9V batt? Or did you use it after all. I don't see it in the finished robot.</p>
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<p>on what software would i download the code?</p>
<p>can you the main circuit diagram.</p>
<p>how is the motor controlled?</p><p>I'm kind of new to the whole the robot thing</p>
<p>The motors are controlled by a DFRobot motor shield. Here's a youtube video describing the shield <a href="https://www.youtube.com/watch?v=Uqtdf1vYM6Q" rel="nofollow">https://www.youtube.com/watch?v=Uqtdf1vYM6Q</a> and here is a link to the manual <a rel="nofollow">http://www.dfrobot.com/wiki/index.php?title=Arduino_Motor_Shield_(L298N)_(SKU:DRI0009)</a></p>
<p>Great job. Very nice.</p><p>Take a look at my instructables too (my BUGBot) <a href="http://www.instructables.com/id/Basic-Principles/" rel="nofollow">http://www.instructables.com/id/Basic-Principles/</a></p><p>Voted.</p>
<p>And i been made analog car. :)) https://www.youtube.com/watch?v=4rYxZ-xUAAI</p>
<p>Nicely documented....Sweet Robot!!!! </p>
<p>A neat and nice project. Keep it up!</p>

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