Step 9: The Sensor

The sensor comes as an array of 8 sensors. There are 2 on the end that can be removed and need to be removed. I used a pair of side cutters to do this. A 9 pin strip of female headers has to be soldered on to the sensor from "GND" to pin "6" of the sensor. I then plugged in a strip of male headers.

These sensors put out an analog voltage based on how much IR light is being reflected back. We can use these to detect the white and black areas on the maze. The sensor outputs a low voltage near 0V if the sensor detects a white surface. The sensor outputs a voltage near VIN if it detects a dark surface. 

<p>To be honest the code is written pretty .. ehm .. *not-so-nice-words* ... BUT when I will find the part about optimizing to ideal route it will surely be helpful and I thank you for that.<br>....<br>we are doing a school project where we have similar robot and we are navigating it through complete mess of loops, dead ends, loops and dead end loops and .. did I mention loops? </p>
<p>Please! You can for mo know: What software to read file &quot;pde&quot; :((</p>
<p>hello,mr.admin,i want to make this project,can you plz provide me the proper circuit of this line maze solver robot working over arudino and its master programing as soon as possible,it will be great help admin</p>
Mr Patric, I like your project. I want to make it but haven't analogsensor. can I use Digital sensor QTR-8RC
<p>Sir,I had tried working Hard to make this BOT and it turned out pretty well.It took more than a month and a half to make it.Finally made it.I just made minute changes in the code.The results were actually amazing.....here is the link of the vid.....Sorry about the middle finger in the video.Those were for my friends they thought that I couldn't make it.....Would soon write Instructable on it....Thank you for this....</p><p><a href="https://drive.google.com/open?id=0B-f1xWTJwulda2QwQVYwMm1scXM&authuser=0" rel="nofollow">https://drive.google.com/open?id=0B-f1xWTJwulda2Qw...</a></p>
<p>can you please give me the code. i have tried making my robot find the shortest path. i would appreciate some help.</p><p>please mail the code alokgrao@gmail.com</p><p>thanks</p>
<p>BTW Ajay, where did you find those sensor arrays?</p>
<p>pololu.com qtr-8ra I think is the model number for the analog sensors.</p>
<p>Nice job!</p>
<p>Dear Patrick,</p><p>Nice work !!!</p><p>I'm trying to make this robot but getting problem with related to algo i think there is some error in code. can you send me the modified code so ill complete my project.</p>
<p>I made this robot but with slightly different parts, (used uno and 12v motor).</p><p>The problem is that my bot is not running fine. While debugging and viewing the output of rightcenter sensor the reading is constant at 1023 and does not change regardless of what I do. </p><p>I think the sensor is faulty.</p>
<p>I made this robot but with slightly different parts, (used uno and 12v motor).</p><p>The problem is that my bot is not running fine. While debugging and viewing the output of rightcenter sensor the reading is constant at 1023 and does not change regardless of what I do. </p><p>I think the sensor is faulty.</p>
<p>very helpful post..thanks !</p>
<p>Got code?</p>
<p>i want to know how would i convert the long path &quot;LLLBSR.....&quot;</p><p>into the direct path in coding</p><p>and thanks for this great post</p>
<p>Now make it so you can place the robot on any point of the maze after it has found the end and it works out where in the maze it is (drives around until it finds a bit it recognizes) then drives straight to the exit once it has got its bearings.</p>
Hii sir can you send me the full code because I'm trying to making this my email id is pratikjaiswal.pj28@gmail.com<br>Thanks in advance
<p>well, the instructions were pretty useful but i am facing a problem with this.</p><p>what should i do if a maze have a single solution(exit) but multiple paths. my bot used two different paths when i used right and left in different runs.</p><p>and definitely the both the paths are of different lengths hence not traversing the shortest one.</p>
<p>if there are white lines and black background instead of black lines and white background where i have to make changes in program..</p>
<p>i wanted use arudino cc intstead of arduino RBB</p><p>will it work if i use external IR sensors </p>
<p>Hey man. I think I found a way to solve (some) looping mazes as well. If the robot has turned left/right (depending on the rule) more than 4 times in a row (which would be the case in a loop), then switch the rule. If it was left-hand rule, switch to right-hand rule and vice versa. This would enable certain looping mazes to be solved.</p>
<p>Please someone mail me the code, please i cant get it dominguezfernandez94@gmail.com please i will apreciate that</p>
<p>Could you repost the code. </p>
<p>brilliant work you have done.. can this project use only 5 sensor.. help is needed..</p>
<p>urgent help... can i use arduino mega, and digital line sensor instead of analog line sensor, also can i use 12v dcmotor for for this project .. i provide link of component that i want to use and need your advice does it can be use..</p><p><a href="http://cytron.com.my/p-mdd10a" rel="nofollow">http://cytron.com.my/p-mdd10a</a></p><p><a href="http://cytron.com.my/p-lss05" rel="nofollow">http://cytron.com.my/p-lss05</a></p>
hi. I dont get the exact parts which you used. firstly, can i use a arduino uno instead of the one which you used?<br><br>can i use regular DC motors? (http://www.rhydolabz.com/index.php?main_page=product_info&amp;cPath=121&amp;products_id=815)<br><br>and can i use a motor driver (http://www.rhydolabz.com/index.php?main_page=product_info&amp;cPath=108&amp;products_id=858)<br><br>if yes, could you please guide me through the process, it would be of great help.<br>thanks
<p>dear can you send me its complete codes ?</p>
That motor driver will work, but you do not want that motor. That motor operates at 12 volts. You would have to get a 12v battery pack and regulate it down to 5v for the other parts. I would find a 5v motor.
<p>need its complete codding please .</p>
<p>I can't get the code. Can somebody reupload it please.</p>
<p>To which pin in arduino should we connect the 2nd pin right next to VCC </p>
<p>Sir,you didn't mentioned the value of the Cap on the Motor Controller Ckt.Also you have not included that in your PCB.Is is not necessary??</p>
<p>Plz give me code with atmega avr 16/32..if it's teotorial i'll highly appreciate that.</p>
<p>Hey Patrick, the link for the code has expired. Do you think we can get an updated one?</p>
<p>the code not download, please help me!!</p>
<p>Mate can u explain the this value for me ? because im not using the same sensor </p><p>(leftCenterReading&gt;200 || <br>rightCenterReading&gt;200 <br>why is 200? </p>
<p>Well done. Honestly I have to say that was the best tutorial I could find on a line solving robot but I have one question. Where can I get the code because the code no longer exist anymore. Can you help me out there. Thanks. :)</p>
<p>Nevermind I found the code I believe something must be wrong with my internet. Wish me good luck improving it. :)</p>
<p>Great Work...<br>Can i use EEPROM library to store the path?<br>U didn't used an LCD... So, were u testing the path and storing the character using serial monitor all the time?</p>
<p>A question:</p><p>how is your PWM pin?</p>
<p>A question:</p><p>I have a l298 driver and Arduino Uno V3</p><p>can you help me to change the code for my robot?</p>
<p>Hi, </p><p>Did you use the 30:1 motor or a different ratio? mMy robot is extremely fast (almost out of control)</p><p>Thanks</p>
<p>Hello,</p><p>The robot I have built does not move in a straight line i.e. it keeps getting off the black line always. </p><p>Can you provide me a solution for this?</p>
Hey, nice work. I'm building a maze solver myself but I have one question if I leave the start point and have a L shaped turn to the right, according to the algorithm I can't make left so leaves my 2 options go straight or turn right, my issue is how do I detect if I can go straight or not, since all the sensor are on the same line, they will be both true for right and straight even if in fact i can't go straight because it's a turn. I tought using another sensor ahead, offseted forward from the line sensors array. Waiting for an answer. Thanks :)
You have to drive forward some to see if the line continues on (i.e. you can go straight) only then does the robot make the decision. This motion is kind of disguised because the robot has to drive forward anyway in order to turn in place and end up centered on the line.
Good ideea, will try that. Thank's for the input. :)
Can u give the PCB layout of ine sensor array?
I did not make the line sensor array. You should be able to get more information about it by visiting the Pololu website.

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