EyeBlock

Theory

A photocell changes resistance as it is exposed to light. The more light it recieves, the less it resists the flow of electricity.
The circuit below is setup like a tug-of-war.
The 10k resistor always has the same strength, and is on team G for Ground (negative).
The photocell gets stronger as it gets more light, and is on team V for voltage (positive).
S (signal) is like the flag in the middle of the rope that shows who is winning.

 

 

Assembly

1. 
   Cut the connectors off one end of the cable
2. 
   Strip about 10mm off the end of each wire
3. 
   Twist one leg of the 10k Ohm resistor and Photoresistor together
   The twisted legs will be connected to the Signal wire later
4. 
   Twist the Voltage (middle) wire to the other (the unused) leg of the photoresistor
5. 
   Twist the Ground (left) wire to the other resistor leg
   Twist the Signal (right) wire to the joined legs (photoresistor and resistor)
6. 
   Solder and trim the the legs short
7. 
   Check with Mr. Dash before continuing

8. 

   Drill a 6mm hole in one side for the photocell
   Drill a 3mm hole in the opposite side for the wires

   
   
9. 
   
   Use a pin to bend the latch that holds the black connector housing on
10. 
    Pull the housing off each wire
11. 
    
12. 
    Place the 3 pin housing on the ends of the wires
    Make sure the metal ends are the right way up so the plastic latch can click into place

 

 

 

 

 

 

Connection Diagram

The EyeBlock can be connected to any Analog Input (A0-A7).
If the EyeBlock is connected backward no damage occures, but all readings are 0.

 

Hints

Example Programs

 

 

Advanced

See the JoyBlock for an example of how to control the WiggleBlock using an Analog Input, you can use the same program with the EyeBlock.