SquidDev: Fix getLocation implementation

2017-05-17T17:27:25Z

Fix getLocation implementation

Latias1290 at 06:10, 28 August 2013

2013-08-28T06:10:25Z

Latias1290 at 05:51, 28 August 2013

2013-08-28T05:51:57Z

Latias1290 at 05:51, 28 August 2013

2013-08-28T05:51:48Z

Latias1290: Created page with "This tutorial will teach you how to make a Turtle more efficient in keeping track of its location when using the GPS API. This is essentially an API that use..."

2013-08-28T05:42:59Z

Created page with "This tutorial will teach you how to make a Turtle more efficient in keeping track of its location when using the GPS API. This is essentially an API that use..."

New page

This tutorial will teach you how to make a [[Turtle]] more efficient in keeping track of its location when using the [[Gps_(API)|GPS API]]. This is essentially an API that uses the native Turtle movement API while using its own movement as a sensor to keep track of its location, so it only requires a GPS signal once, until it is turned off. This API requires every Turtle you want to use the API with to have it installed. I recommend using an [[Advanced_Computer|Advanced Computer]] to write it on, move it to a [[Disk]] with a [[Disk_Drive|disk drive]] and moving it to the Turtle. Alternatively, if you are on Singleplayer or a Multiplayer admin and have access to the mod file, you can move it into the turtle/rom folder to have it automatically installed on every new turtle that is placed.

Important: When starting, the program assumes that it is facing west, so first you must face West and then place the turtle. Here are some ways to check where you are facing:
You can see the sun/moon rising right in front of you. You are facing East.
You can see the sun/moon falling right in front of you. You are facing West.
Clouds go west. Check where they go.
Press F3 and locate the number behind "f". This one is below "x", "y" and "z". If this number is 0, you are facing North. If this number is 1, you are facing West. If this number is 2, you are facing South. If this number is 3, you are facing East.

== Code ==
''Note: This will only work on a Turtle. That said, even if it worked on a [[Computer|computer]], it wouldnt have any practical use because a computer cant move.''<br />
Before you start, you must add this to the program that you want to use it with at the top line:
os.loadApi("tst")
This will allow the program to use the API. This tutorial assumes that you use the file name "tst" for the API, but if you like to you can change it. You must then also change every reference to "tst" in your program, including the line above.
Write this in the computer/turtle:

-- Turtle Self-tracking System created by Latias1290.
-- Copyright (c) Dirk Kok 2013.

local xPos, yPos, zPos = nil
face = 1
cal = false

function setLocation() -- get gps using other computers
xPos, yPos, zPos = gps.locate()
cal = true
end

function manSetLocation(number x, number y, number z) -- manually set location
xPos = x
yPos = y
zPos = z
cal = true
end

function getLocation() -- return the location
if xPos != nil then
return xPos, yPos, zPos
elseif xPos == nil then
return nil
end
end

function turnLeft() -- turn left
if face == 0 then
face = 1
elseif face == 1 then
face = 2
elseif face == 2 then
face = 3
elseif face == 3 then
face = 0
end
end

function turnRight() -- turn right
if face == 0 then
face = 3
elseif face == 1 then
face = 0
elseif face == 2 then
face = 1
elseif face == 3 then
face = 2
end
end

function forward() -- go forward
turtle.forward()
if cal == true then
if face == 0 then
zPos = zPos - 1
elseif face == 1 then
xPos = xPos - 1
elseif face == 2 then
zPos = zPos + 1
elseif face == 3 then
xPos = xPos + 1
end
else
print("Not Calibrated.")
end
end

function back() -- go back
turtle.back()
if cal == true then
if face == 0 then
zPos = zPos + 1
elseif face == 1 then
xPos = xPos + 1
elseif face == 2 then
zPos = zPos - 1
elseif face == 2 then
xPos = xPos - 1
end
else
print("Not Calibrated.")
end
end

function up() -- go up
turtle.up()
if cal == true then
yPos = yPos + 1
else
print("Not Calibrated.")
end
end

function down() -- go down
turtle.down()
if cal == true then
yPos = yPos - 1
else
print("Not Calibrated.")
end

function jump() -- perform a jump. useless? yup!
turtle.up()
turtle.down()
end

== How to Use ==
This might seem daunting at the first moment. But dont worry, I will walk you through it. Note that to use it properly, you must always put "tst." in front of it, or how you named it followed by a dot. So if I wanted to have my turtle go 1 block forward, I typed "tst.forward()". Note that if you do not do either tst.getLocation OR tst.setLocation(coords), the API will print "Not Calibrated." every time you use a command. This will not prevent you from using it, however.

=== setLocation ===
To use this, you will need at least 4 computers equipped with a Wireless Modem, and having it host a GPS. More info about that [[Gps_(API)|here]] and [[Gps_(program)|here]].

=== manSetLocation ===
For this one you will need to know the location of your turtle. Any location will work, but the API loses its point if you use another coordinate set.
A good way to obtain the coordinates is to open up the debug screen(press F3), stand on the turtle, write down the x, y and z fields, substract 1 from the Y coordinate and use these.

=== getLocation ===
This one is pretty simple. It returns the coordinates. Note that you will have to overwrite all of them.
For example, if we had the variables x, y and z, and we wanted to have the value set to our location, we did this:
x, y, z = tst.getLocation()
Simple right? Note that this will return nil if you are not calibrated, which means if you do it before you do setLocation or manSetLocation, x, y and z will be null!

=== forward, back, up, down, turnLeft and turnRight ===
This one is pretty easy as well. It makes your turtle move 1 block in the direction you used(its obvious which function goes where) and update its location according to where it went.

=== jump ===
This one works a bit different. It makes the turtle go up, then go down. "But thats useless!" you might say, and indeed it is!

← Older revision		Revision as of 06:10, 28 August 2013
Line 141:		Line 141:
	=== jump ===		=== jump ===
	This one works a bit different. It makes the turtle go up, then go down. "But thats useless!" you might say, and indeed it is!		This one works a bit different. It makes the turtle go up, then go down. "But thats useless!" you might say, and indeed it is!
		+
		+	[[Category:Unofficial APIs]] [[Category:Tutorials]]

@@ Line 33: / Line 33: @@
   function getLocation() -- return the location
-   if xPos != nil then
+   if xPos ~= nil then
     return xPos, yPos, zPos
-   elseif xPos == nil then
+   else
     return nil
    end

@@ Line 15: / Line 15: @@
   -- Turtle Self-tracking System created by Latias1290.
-−
   local xPos, yPos, zPos = nil
   face = 1

Turtle GPS self-tracker expansion (tutorial) - Revision history

SquidDev: Fix getLocation implementation

Latias1290 at 06:10, 28 August 2013

Latias1290 at 05:51, 28 August 2013

Latias1290 at 05:51, 28 August 2013

Latias1290: Created page with "This tutorial will teach you how to make a Turtle more efficient in keeping track of its location when using the GPS API. This is essentially an API that use..."