/ / Introduction

The bot that you are going to build will move when light is detected.

The Jitterbug is an extremely simple battery-powered photophobic robot that takes advantage of a light sensor. Light sensors are among the cheapest and most reliable parts available.

When building the bot, you want to keep it as light as possible.

/ / Parts

• Photocell
• 2N3904 transistor
• 4.7K ohm resistor (yellow, purple, red)
• Vibrator motor
• 3 Volt CR2032 button cell battery
• Battery clip
• Hook-up wire
• (optional) Ball bearings

/ / Instructions

1. Solder a red piece of wire to the power terminal and a black piece of wire the the GND terminal.
   
   
   
   

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2. This is a transistor:
   
   Hold the transistor with its legs up and the flat face away from you.
   
   

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3. Solder one leg of the photocell to the right leg of the transistor (the collector) and the other leg of the photocell to the center leg of the transistor (the Base).
   
   

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4. Solder the resistor also to the Base of the transistor (the center leg).
   
   
   
   
   

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5. Solder a shorter piece of wire from the positive terminal of the battery holder to the right leg of the transistor (the collector).
   
   

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6. Here I bent my leads around the battery holder
   
   
   

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7. Solder the left leg of the transistor (the emitter) to one of your motor's terminals.
   
   
   

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8. Solder the other end of the resistor to the GND terminal and also the other terminal of the motor.
   
   
   

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9. Now you can add a little personality. You can hot glue ball bearings to the bottom, or you could bend the long leads attached to the battery's terminals to add balance. Decorate your bot.
   
   
   
   
   
   
   

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10. Add the battery and shine a light on the bot.
    
    

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11. Compete with another bot:
    
    1. Place your bot on the black circle and shine a light on the bots. The last one on the board wins.
    2. Dim the lights and using laser pointers, see who can get their bot to escape the circle first.
    
    
    

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