Transcript Home Doormat Buzzer and Welcome Chat in

Hacking Minecraft on the Raspberry Pi
using Python
Lesson 4
1
Starter
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Switch on your Raspberry Pi.
Open Minecraft
Open Idle (not Idle 3)
Click on File>New File
This opens up the Idle editor where you can
write and edit your Python code
• Open Minecraft>Create New World (Minecraft
must be open for you to hack it)
2
Objective of the lesson
Use Python to control a game called Minecraft
• All of you will:
– Use Python to make text print to the screen
• Most of you will:
– Use code to make a doormat to tell you when you have
arrived home
• Some of you will:
– Use a Pibrella to make an electronic doorbell when you have
arrived home
3
Type the following into the editor
You always use these lines first in your Minecraft code
This connects your code to Minecraft so that you can hack
it. Careful, Python code is case sensitive
Remember to have Minecraft open)
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
You need to add a new line of code
mc.postToChat (“Hello World”)
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
mc.postToChat (“Hello World”)
Press F5 to save and run the program
Your message should print to the screen
Change the message which prints to the screen.
We now want it to print a message to the screen if
you arrive home and stand on the doormat
We need to find our position.
We can use
pos = mc.player.getTilePos()
to find the coordinates of the tile below the player.
This gives a x,y,z as integers
(whole numbers) which is better when tying to
match up a player’s position against the position of
the doormat.
Add this line of code in
You can get it to print your position using the
following code
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
pos = mc.player.getTilePos()
mc.postToChat (“Your x position is ” +str(pos.x) + “, your
y position is ” +str(pos.y) + (“, your z position is ”
+str(pos.z) )
pos.x is your position along the x axis
pos.y is your position along the y axis
pos.z is your position along the z axis
str stands for string. This converts the x,y,z numbers into text so that it
can be printed to the screen
You now need it to keep updating your position
You will need to
- import time
- add a while True:
Add a time.sleep command depending on how
quickly you want your position to update
You can get it to print your position using the
following code
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
while True:
pos = mc.player.getTilePos()
mc.postToChat (“Your x position is, ” +str(pos.x) + “, your y
position is ” +str(pos.y) + (“, your z position is ” +str(pos.z) )
time.sleep(2)
Build a house and identify the x,y,z coordinates of the tile outside
of the door (the doormat). Mine is at x=10,y=0,z=10
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
while True:
pos = mc.player.getTilePos()
mc.postToChat (“Your x position is, ” +str(pos.x) + “, your y position
is ” +str(pos.y) + (“, your z position is ” +str(pos.z) )
time.sleep(2)
mc.postToChat (“Your are looking for x=10, y=0, z=10”)
time.sleep(5)
I have added some code. What will it do?
We will need an line of code using ‘if’ to see if we are at the doormat
position. To check to see if a value is the same as another value held in a
variable, we use ==
Your y coordinate will automatically match if you are stood on the ground.
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
while True:
pos = mc.player.getTilePos()
mc.postToChat (“Your x position is, ” +str(pos.x) + “, your y
position is ” +str(pos.y) + (“, your z position is ” +str(pos.z) )
time.sleep(2)
mc.postToChat (“Your are looking for x=10, y=0, z=10”)
time.sleep(2)
if pos.x ==10 and pos.z==10:
mc.postToChat (“Your are home”)
else:
mc.postToChat (“Are you lost?)
What you have learned
Strings Strings are a kind of data type called
text. They have speech marks around them.
Same as == This compares a value to a value
held in a variable. e.g. Your age is 12. This is a
value. I keep asking you is your age 5,6,7 etc
which always returns a false value until I ask is
your age 12? and then this returns a true value
postToChat() This displays text in the Minecaft
game
Challenge 1
We will now get a Pibrella doorbell to sound a ‘success’ tune if you
land on the doormat. You need to add in the line
pibrella.buzzer.success()
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
mc.postToChat (“Your x position is, ” +str(pos.x) + “your y
position is, ” +str(pos.y) + (“your z position is ” +str(pos.z) )
time.sleep(2)
mc.postToChat (“Your are looking for x=10 and z=10”)
time.sleep(2)
while True:
if pos.x ==10 and pos.z==10:
mc.postToChat (“Your are home”)
else:
mc.postToChat (“Are you lost?)
We will need an line of code using ‘if’ to see if we are at the doormat
position. To check to see if a value is the same as another value held in a
variable, we use ==
Your y coordinate will automatically match if you are stood on the ground.
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
while True:
pos = mc.player.getTilePos()
mc.postToChat (“Your x position is, ” +str(pos.x) + “, your y position is
” +str(pos.y) + (“, your z position is ” +str(pos.z) )
time.sleep(2)
mc.postToChat (“Your are looking for x=10, y=0, z=10”)
time.sleep(2)
if pos.x ==10 and pos.z==10:
mc.postToChat (“Your are home”)
pibrella.buzzer.success()
else:
mc.postToChat (“Are you lost?)
pibrella.buzzer.fail()
time.sleep(2)
Did you get it correct?
import mcpi.minecraft as minecraft
mc = minecraft.Minecraft.create()
import time
import pibrella
mc.postToChat (“Your x position is, ” +str(pos.x) + “your y position
is, ” +str(pos.y) + (“your z position is ” +str(pos.z) )
time.sleep(2)
mc.postToChat (“Your are looking for x=10 and z=10”)
time.sleep(2)
while True:
if pos.x ==10 and pos.z==10:
mc.postToChat (“Your are home”)
pibrella.buzzer.success()
else:
mc.postToChat (“Are you lost?)
pibrella.buzzer.off()