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wiki:v2:lego_line_following_demo [2019/01/31 00:48]
pixycam
wiki:v2:lego_line_following_demo [2019/01/31 01:42]
pixycam
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   - Attach Pixy2 and plug into port 1 as shown. ​ Note how Pixy2 is pointed down (It's going to be tracking lines on the ground!)\\   - Attach Pixy2 and plug into port 1 as shown. ​ Note how Pixy2 is pointed down (It's going to be tracking lines on the ground!)\\
 {{wiki:​v1:​img_5351_result.jpg?​400}} {{wiki:​v1:​img_5351_result.jpg?​400}}
 +  - Here's what the finished robot should look like.\\ 
 +{{wiki:​v1:​img_5345_result.jpg?​400}}
  
 ==== Cables (IMPORTANT!) ==== ==== Cables (IMPORTANT!) ====
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 {{wiki:​img:​3e3b64f2ff052ac58280fa2315eff9d803714e6e.png}}\\ {{wiki:​img:​3e3b64f2ff052ac58280fa2315eff9d803714e6e.png}}\\
    
-  - Browse to the location where you unzipped the "LEGO blocks and examples"​ file (which you can download [[https://​pixycam.com/​downloads-pixy2/​|on this page]]), and then to the **examples** directory and select "​line\_follow.ev3"​ and click on **Open**+  - Browse to the location where you unzipped the "LEGO blocks and examples"​ file (which you can download [[https://​pixycam.com/​downloads-pixy2/​|on this page]]), and then to the **examples** directory and select "​line\_follow.ev3"​ and click on **Open**. You should see a program that looks like this (below).\\ 
-  - Click on the "​track"​ tab. You should see a program that looks like this (below).\\ +{{wiki:​v1:​image_741.png}}\\
-{{}}\\+
   - Draw a smooth line on a large sheet of paper using a black marker. ​ Taping several standard-sized pieces of paper together to create a larger sheet of paper is a good approach. ​ You can make a circle, oval, figure-eight,​ or something more complex, but keeping it simple is good for the first test.   - Draw a smooth line on a large sheet of paper using a black marker. ​ Taping several standard-sized pieces of paper together to create a larger sheet of paper is a good approach. ​ You can make a circle, oval, figure-eight,​ or something more complex, but keeping it simple is good for the first test.
   - Place your robot on the line that you've drawn and clicking on the play icon in the lower right corner of your EV3 software window.\\   - Place your robot on the line that you've drawn and clicking on the play icon in the lower right corner of your EV3 software window.\\
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   - If your robot turns away from the line, make sure that the motor cables aren't crossed. ​ That is, if you are facing the motor ports (the back of the robot), the left motor connects to port B, the right motor connects to port A.   - If your robot turns away from the line, make sure that the motor cables aren't crossed. ​ That is, if you are facing the motor ports (the back of the robot), the left motor connects to port B, the right motor connects to port A.
-  - If your robot starts turning left before the line curves to the left (for example), try tilting Pixy2 more downward toward the paper. ​ That is, if Pixy2 is tilted too far up, it will see too much of the line in front of it and "​anticipate"​ any turns. ​ On the other hand, this might be what you want. :)   +  - If your robot starts turning left before the line curves to the left (for example), try tilting Pixy2 more downward toward the paper. ​ That is, if Pixy2 is tilted too far up, it will see too much of the line in front of it and "​anticipate"​ any turns. ​ On the other hand, this might be what you want. :) 
-  - Although it's unlikely, sometimes the Vector can become "​inverted "such that the Vector points down instead of up, which will cause your robot to back-up (reverse) instead of move forward. ​ It will resolve itself because your robot will back-up and turn around such that the Vector is pointing up again, but it can be unexpected. ​ The easiest way to prevent ​the Vector from being is to place a blank sheet of paper in front of Pixy2 such that it loses the current Vector, then remove the paper before you start the program. ​ After you remove the paper, Pixy2 will see the line in front of it, assign it as the Vector, and (by default) choose an upward orientation. ​ Your robot will then move forward.+  - Although it's unlikely, sometimes the Vector can become "​inverted"​ such that the Vector points down instead of up, which will cause your robot to back-up (reverse) instead of move forward. ​ It will resolve itself because your robot will back-up and turn around such that the Vector is pointing up again, but it can be unexpected. ​ The easiest way to prevent ​this is to place a blank sheet of paper in front of Pixy2 such that it loses the current Vector, then remove the paper before you start the program. ​ After you remove the paper, Pixy2 will see the line in front of it, assign it as the Vector, and (by default) choose an upward orientation. ​ Your robot will then move forward.
  
  
-===== Making Turns =====+===== Making Turns at Intersections ​=====
  
 If your line drawing has an intersection,​ you can tell your robot always turn left or always turn right (for example) by "​hard-coding"​ the Turn Angle. ​ With the program stopped, try setting the Turn Angle to -90 degrees. If your line drawing has an intersection,​ you can tell your robot always turn left or always turn right (for example) by "​hard-coding"​ the Turn Angle. ​ With the program stopped, try setting the Turn Angle to -90 degrees.
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-===== What's Next =====+===== What's Next=====
  
 Can you extend this demo to make turns based on barcodes? ​ Barcode images (including roadsigns!) are available [[https://​pixycam.com/​downloads-pixy2/​|here]]. Can you extend this demo to make turns based on barcodes? ​ Barcode images (including roadsigns!) are available [[https://​pixycam.com/​downloads-pixy2/​|here]].
  
  
wiki/v2/lego_line_following_demo.txt · Last modified: 2019/01/31 01:43 by pixycam