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First Steps

What we will learn: How to turn an LED off and on with the Raspberry Pi General Purpose Inputs and Output Pins with Scratch

One 220 ohm  resistor

or

 

 

Materials:

Two male to male jumpers

One LED

Follow the instructions below and try playing with the code to see what changes you can make

Click here first

then click here

2.Click on More Blocks and Add an Extension

click here

then here

3.Click on the Raspi picture to add the GPIO

click here

then click OK down here

4.Cool!  These are the General Purpose Input Output blocks we will need to connect to Scratch to the Raspberry Pi

these are your GPIO blocks

                                  WARNING!!!!!!                                  

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5.Plug your male jumper into GPIO 5 and into any number below the GND on your T-Cobbler on your bread board 

Do not start randomly plugging in wires or LEDs into the

breadboard.  You can damage or destroy the Pi!  Only use the numbered GPIO's and follow each tutorial step closley 

this is GPIO 5 plug your jumper right across from it

then plug the other end into your breadboard any number will be ok!

6.Grab your LED, the LONG LEG (anode+) is the one you want to plug across from the jumper

LONG LEG (anode+)

short leg (cathode-)

6.Put the LONG LEG into the hole ACROSS from the jumper and the short leg next to it

LONG LEG (anode+)

short leg (cathode-)

7.Grab a 220 Ohm resistor.  Check out this site and place in the colour code in the menu to see what kind of resistor you have

Red

Red

Brown

Gold

or

Red

Red

Black

Black

Brown

9.Place the resistor next to the cathode (short leg) and the other end in the ground 

put your resistor in here in ground 

the resistor reduces the amount of current 

you current will run up here to the - symbol

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10.OK now lets turn that LED on! Pull out a "when clicked block" a "forever block" and a "set gpio to output high" block.  Place "5" in the gpio block.  Then click the green flag 

from More Blocks

from Events

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11.To get the light blinking follow the code below! Set the other gpio block to "output low"

set to "low"

set to "high"

12.a)GPIO 5 is set to HIGH which sends 3.3 volts to the pin

b)GPIO 5 is set to LOW which sends 0 volts to the pin

c)You are making it wait 1 second in between

d)the forever loop makes to loop forever!

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                               Taking it Further

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You will need to wire up 3 blinking at once to move to the next challenge, or maybe you are feeling adventurous and can do more?

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there is a mistake here, what do you think it is?

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