irfan  
                
               
               
              
                  
                    December 15, 2012,  4:38pm
                   
                   
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The gear motor wheels, multi-directional wheel and the plastic sheet. I cut out 6 x 13 cm plastic for base.
Glued the wheels to make the body and connected the motors to the components.
After its completed. 
Robot Schematic
  
 
Light Following Robot without using microcontroller. This wheeled robot does not avoid collision. It runs towards the light or just brighter areas.
Control method: non-autonomous, moves toward the light or bright areas 
Sensors / input devices: 2x LDR, 2x BC547 Transistors, 2x 2 x 30 ohms Resistors, 2 x Gear motor wheels, 1 x multi-directional wheel, 9 volt Battery. 
Target environment: indoor 
 
 
 
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/light-following-robot  
             
            
               
               
               
            
            
                 
                 
              
           
          
            
            
              **Schematic ** Schematic please?
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    December 16, 2012,  1:01pm
                   
                   
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              Robot schematic is added. 
Robot schematic is added. Its a very straight forward circuit. 
             
            
               
               
               
            
            
                 
                 
              
           
          
            
            
              Gratulation 
Hello Irfan! I simply and goodly congratulate! Is the 30 ohms of resistance actual only 30 ohms ???  Oderlachs
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    December 17, 2012,  3:07pm
                   
                   
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                I read the colors from a
Thank you   I read the colors from a calculator, its a tiny one. for this it doesnt matter if its bellow 100 ohm. I might be wrong about it been 30 ohm.
             
            
               
               
               
            
            
                 
                 
              
           
          
            
            
              We have a new “first robot”! 
Wow! That robot looks great and performs great! Congrats on the build!
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                mikuuu  
                
               
               
              
                  
                    February 24, 2014,  1:11am
                   
                   
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              Please Help 
Hello there. I’m trying to do this as my project but something seems wrong can you please help?
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                mikuuu  
                
               
               
              
                  
                    February 24, 2014,  1:11am
                   
                   
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              Please Help 
Hello there. I’m trying to do this as my project but something seems wrong can you please help?
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                gromer  
                
               
               
              
                  
                    April 21, 2014,  3:51am
                   
                   
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              about lightseeker 
Hi man did you done this project ? i can help 
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                joya  
                
               
               
              
                  
                    May 4, 2014,  3:50am
                   
                   
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              works without light 
I have triple checked my circuit and it works even without light.  Any idea what’s wrong?
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                joya  
                
               
               
              
                  
                    May 4, 2014,  2:25pm
                   
                   
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              Need help with light seeking robot 
Hi you mentioned you could help on this one.  I built it and triple checked the circuit but it works even without light.  Do you know why?
 
thanks!
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    May 6, 2014, 10:34am
                   
                   
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              sorry for the late reply… 
sorry for the late reply… can you share your diagram?
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    May 6, 2014, 10:36am
                   
                   
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              share the exact components 
share the exact components used and diagram so i can check…
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                absdr  
                
               
               
              
                  
                    October 16, 2015,  6:30am
                   
                   
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              is something work with the circuit?Please Help! 
So I created the model as you said.First I created only the left motor to see if it works and it didnt.When I connected the 9v Battery the transistor fried/heated up. So is there something work? btw i used a 22ohm Resistor since i couldnt find a 30ohms resistor at any shop. So please helpbtw your model is nice and i would like to have one like that too,so HELP!  
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                dannyv  
                
               
               
              
                  
                    October 28, 2015,  4:01pm
                   
                   
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              The bc547 can only handle 
The bc547 can only handle 100mA. That is not very much. A bc337 for example can handle 800mA.
If you have a multimeter you can measure the current your motor needs.
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    November 21, 2015, 10:16pm
                   
                   
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              so sorry all i was away for 
so sorry all i was away for some time on a project. Let me make a simple how to vdo probably post next week. Thanks
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                pierp20  
                
               
               
              
                  
                    September 1, 2017, 10:52am
                   
                   
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              light follower circuit problem 
Hi,
I tested the circuit with electronic simulator software.
i have the same problem works all the time (with light and no light)
to resolve problem, change 30 ohms resistor with 10k (worked correctly).
 
 
             
            
               
               
               
            
            
                 
                 
              
           
          
            
              
                pierp20  
                
               
               
              
                  
                    September 1, 2017, 11:02am
                   
                   
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              Robot light follower 
Hi,
Circuit problem!
i tested this circuit with electronic simulator software.
The motors are on all the time (light and no light)
To resolve the problem i replaced resistor 30 ohms with 10k (working fine)
             
            
               
               
              1 Like 
            
            
                 
                 
              
           
          
            
              
                irfan  
                
               
               
              
                  
                    December 10, 2018,  9:20pm
                   
                   
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              I might have read the resistor wrong. thanks