[How to guide] GPS Global Position System (2024)

http://en.wikipedia....inate_systemGPS in Computer craft is a way to find Turtle or Computer positions.This guide will explain how to set up a working GPS cluster. a GPS cluster is a group of GPS server computers arranged in a way to give best accuracy and coverage.

A GPS server is a computer with a rednet wifi modem that when asked will tell passing computers / turtles where it is its location in X , Y , Z .This combined with the distance from the sever allows a computer / turtle to locate where it is. the turtle must have this information from four different severs so it can Trilateration its location. This group of turtles is called a GPS cluster.

The way the severs are positioned has an affect on how accurate / reliable your system is. In Picture one you can see that i have computers In a pattern that pattern allows the position to be found in X Y and Z if you have four computers in a line along Y It would not be able to identify its hight or its X position. You must have computers on different locations. My recommendation is to use the below configuration I use it all the time ant it is very accurate affective and compact.
[EDIT] I derped Hard This is the Correct Picture [/EDIT]

After setting up four computers in this pattern at the top of the world.Set up a startup file on each computer with the continence as the picture shown.Put this in a file named startup

shell.run("gps","host",x,y,z)

replace the x y z with numbers from the picture

Example computer A's startup file would contain

shell.run("gps","host",0,3,255)

after this reboot the computer's and repeat the process for the other three computers using the numbers from the picture.

You should now be able to check GPS coordinated from any where within a 370 Meter radius of the cluster.

For more information on the math behind GPS see http://en.wikipedia....i/Trilateration
For more information on coordinate systems see http://en.wikipedia....ordinate_system

Make a turtle with wifi and run gps locate. it should show position. use go to move the turtle and check again with gps locate

Download [CC_1.41] BENCH v1.3 multi porous testing utility using Turtle Driver option press "g" to check for GPS location.

I hope this was helpful as the GPS system is extremely useful.

GPS builder program
neonerz has created a automatic build script for GPS satellites
http://www.computercraft.info/forums2/index.php?/topic/9528-gps-deploy-10/

abc, on 03 August 2012 - 08:12 PM said:

you only need 3 computers, if you look at the gps code it can narrow a position based on only 3 positions and distances
also i have a program to scramble or crash recon turtles so PM me if you plan on having a huge turtle battle

I have tried with only three and get mixed if best results you are right for spherical trigonometry all you need is three But given CC's double floating point the math cant determent with accuracy its position so uses a fourth to make final confirmation.

this was tested in ver 1.3 so maybe it has been improved in 1.41 If you could test that three configuration I would be appreciable.
[EDIT]
Made a new test world built and tested antenna as seen in opening post all worked . turned off one computer and it shows this. proving it needs at least four for locating its position
[With three GPS server's on]

[with four GPS server's on]

[/EDIT]

What we need is some sort of signal booster block. Possibly a powerful relay block that only transmits in a straight line?

Also, I think if the computers are spread out and none of the positions are similar then the computers only need three coordinates. You have two of them at 0 in that picture, which doesn't tell the turtle as much.

How it works:
The rather messy diagram below shows GPS A, GPS B, and GPS C - three computers on a 2D plane sending their distance from a Turtle. the Distance labels are the radiuses of each circle, the iX labels are intersections of the circles.

GPS A responds with Distance A, putting the turtle anywhere on the green circle.
GPS B responds with Distance B, meaning the turtle has to be on the green AND blue circles. This could put it at either iA or iD - still not enough info.
GPS C responds with Distance C, meaning the turtle has to be on ALL circles. The only option is iD - the turtle must be there. The turtle realizes this and tells itself that it is there through some serious complicated math.

This is a Experimental and possibly bug riddled code

GPS builder turtle program.

This program sends a turtle up as far as it can go then builds a GPS cluster

Instructions < Reed

[WARNING] This is experimental code there are probably bugs and errors in it you may loose items when using this. I give no Warner to this code. use at your own risk

if you already have working GPS in your world DON'T USE THIS it will cause you a Big problems

I would recommended tying this out in a New creative world before using it in a real survival world so you know what is does.

place a turtle can be mining or normal WIFI not required.

place turtle with a clear path to the sky (no trees or obstacle above it)

add 600 fuel (one bucket of lava is 1200)
add 4 computers to slot 1
add 4 wifi modems to slot 2
If you are using a Mining turtle then you only need one disk drive in slot 3 and you will get it back. if you are not using a mining turtle then you will need four disk drives in slot 3
place a BLANK disk in slot 4

RUN this program.
http://pastebin.com/gLTwfr8V

press Enter when you have it set up correctly and it will fly up into the sky place Computers turn them on and comeback down.

There is no back door into the computers so ounce they are up there they are staying there you can edit there code after this.

all going well your turtle returns with the disk to ground level. Report bugs here and I will hunt them down.

FuzzyPurp, on 29 August 2012 - 08:13 PM said:

Nice work BST- alot of people will appreciate this, including myself.

Thanks. When I have cleaned it up and hardened it against mob interference I will release a more stable version. for now the warnings are still relevant (as no check for movement are made) . I have used it in SSP and it worked fine.

FuzzyPurp, on 04 September 2012 - 12:21 PM said:

I think Direwolf used your design in his SMP-LP ep 51 :D/>/>

He did! :P/>/>

Thanks for the guide. :D/>/>

When I tried this I saw the note "at the top of the world". Never mind for a moment that you call the up down axis Z (which is cartesian coords as I learned them) and minecraft calls this Y…I went up to about Y=250 and placed this GPS server set up. When I got back down and tried "gps locate" in a computer, it was unable to receive anything from the servers.

I went looking and found this in configs/mod_ComputerCraft.cfg:

modem_range=64

When I changed this to 192, everything worked and I was able to "gps locate". So I'm wondering how you got this server farm to work? Am I missing something important like wraparound vis 8-bits or something?

Slye, on 07 September 2012 - 05:32 AM said:

Thanks for the guide. :D/>/>

When I tried this I saw the note "at the top of the world". Never mind for a moment that you call the up down axis Z (which is cartesian coords as I learned them) and minecraft calls this Y…I went up to about Y=250 and placed this GPS server set up. When I got back down and tried "gps locate" in a computer, it was unable to receive anything from the servers.

I went looking and found this in configs/mod_ComputerCraft.cfg:

modem_range=64

When I changed this to 192, everything worked and I was able to "gps locate". So I'm wondering how you got this server farm to work? Am I missing something important like wraparound vis 8-bits or something?

you are not using the most resent version of computer craft. Computers range increases the higher they are. also dan200 doesn't recommend using the "real world" coordinates and recommends that "Relative coordinates" be used instead. the reason that minecraft uses Y for the X axis is because it allows the game to some rendering shortcuts saving CPU time. I might add that the F3 is for debugging not for finding location and will most likely be removed in time.

BigSHinyToys, on 07 September 2012 - 06:04 AM said:

you are not using the most resent version of computer craft. Computers range increases the higher they are. also dan200 doesn't recommend using the "real world" coordinates and recommends that "Relative coordinates" be used instead. the reason that minecraft uses Y for the X axis is because it allows the game to some rendering shortcuts saving CPU time. I might add that the F3 is for debugging not for finding location and will most likely be removed in time.

Relative coordinates? So … where do you get those if not from the information in F3?

Do you mean keeping track of where your turtle moves and letting the origin be where you started the turtle?

Slye, on 07 September 2012 - 06:22 AM said:

Relative coordinates? So … where do you get those if not from the information in F3?

Do you mean keeping track of where your turtle moves and letting the origin be where you started the turtle?

You chose where the coordinates start then all other coordinates are relative to that. I make the origin bellow my main base normally. Origin being the point where x y and z are 0 this is bellow my main house. you also chose what direction is north. I normally pick the front of my house. I pick the top of the world as Z 255 and then make all other GPS towers with in GPS range and just get the coordinates for them from using gps locate. basically you chose where and what the coordinates are. you can use Y or Z for up and down it is all up to you. for simplicity sake I just go with Z is up down as that is how i learned it before I started using CC and it could be argued that it is the right system.

Hey BigSHinyToys,

I am working on a way to allow an Airship to move via the Cartesian Coordinate system and it came to me that perhaps a Computer from Computer Craft would be able to talk to a GPS system to do so. IE: the computer asks for a target location via XYZ coordinates, then calculates it's current location and then slowly move (the only way you can move with Frame Motors) from point A to point B.

1) Do you think that is possible?
2) What would be the best way to implement said system?

I assume that we would need to set up at least 1 GPS system, if not more then one… say about 4. Each station with a full 4 rig setup and have them talk to each other via the RedNet system already in the world. With at least one full on HOST system setup in the GPS Ring. Looking at the above image of the overlapping GPS rings would show how a multiple GPS system would allow for longer distances to be reached/mapped.

I understand that it would take some time to program this… in fact I already have a working check list started on this very subject. I would welcome any input you could provide. Thank you in advance for your time &amp; assistance on this matter.

KelticRaven

@KelticRaven

in the case of an air ship it would probably be better to have a turtle in the ship flying it and that turtle storing its location in a file inside the turtle. Turtles return true if they have moved and false if they haven't this can be harnessed to make a turtle fly blind with out GPS cluster set up if you tell it its starting location. I would have one GPS cluster just as a point of reference if something goes wrong you will know where you are because of the cluster. as for making the ship go places if there is no obstacle then a simple move on Z then move on Y then Move on Z program should do it. If you want to avoid obstacle then a more complex program would be needed but I'm guessing you want to stay hight above the ground.

To summarize:
A turtle flying the ship storing its location and changing that every time it moves. the smart move API might be of assistance I haven't worked with it but it should have a tracking system for turtle movement. It would get its starting location from the GPS cluster but from then on would not require to be in range This would allow you to fly any ware you want and not worry about range to clusters.

Lyqyd, on 20 November 2012 - 02:58 PM said:

For the purposes of a tutorial, it would be better to use Minecraft's (significantly more sensible) coordinate system and axis assignments. Preventing confusing amongst the readers is more important in a tutorial setting than promulgating your own opinions on which axis should be what.

I can only respond to this by saying dan200 doesn't like people using the real coordinates. and using a debugging too s as a gps is a cheat / hack. that said if you pay the game and ignore that tool with will likely be removed at some point then using the real world system on coordinates would make more sense. If would would like to remove this tutorial and replace it will one you conciser correct I would ask you consult with dan200 or Cloudy first before doing so.

tiin57, on 20 November 2012 - 04:18 PM said:

You do realize that the picture is completely backwards, right?

what is backwards ??

I have done this on my AirShip. At first I used a RedPower computer, because they don't loose their texture when moved by frames, but then I upgraded to tekkit 3.1.3 and I can move ComputerCraft computers on the ship.
My computer controls several transmiters that control the engine of the ship. 6 for the 6 axis movement.
It uses a bundleded cable output to acheive this.
As for the GPS system, I must warn you, it can go out of range pretty quick, so you will need to scatter GPS towers around where you want to travel.
Also make sure to have a world anchor on your ship so it will not have problems on unloaded chunks.
(horrible things can happen to your ship if you don't have that, I found my ship slashed in 2 and separated by 8 blocks)
I have several ways to control the ship. with multiple remote controls, from docking stations (airports), from on board.

So to answer your questions:

1) Do you think that is possible?
Yes is possible

2) What would be the best way to implement said system?
I used a computer (not a turtle as suggested earlier), using bundled cables, controlling transmitters.
As for the GOTO program. I have a GoToXZ function where I provide the final destination, and it will start looping pulses to the engine until it reaches the destination. A normal computer can read its own location using gps.locate() same as the turtles.

The fun part is to make everything stick into panels.

leftyisgod, on 13 December 2012 - 03:29 PM said:

I have a redpower mobile quarry with an attatched computer and modem. I also have a gps tower set up. I would like to make the computer send a pulse to a specified bundled cable color (diff color wire to a diff frequency to each motor moving the quarry) could someone give me an example on the ways/ codes to do this? i have done simple programs but not anything this big. Thank you for any help

It seems I am trying to do exactly the same thing.
I've set up 4 computer modems for the GPS signal. There is a computer on the quarry with also a modem attached.
My code is not yet finished, but I'm able to do 'goto x y z' and then it requests it current position, substracts that from the destination coordinates, and the result of that is how many blocks it needs to move.
So that result, is the count for the for loop.
Here is the (simple, not yet finished) code:

function showInfo()shell.run('clear')print("Quarry control center 1.0")print("-------------------------")print("Commands:")print("dig, moveto")print("------------------------------------")endshowInfo()------------------------------------local cableside = "back"local up= colors.yellowlocal down = colors.redlocal left = colors.orangelocal right = colors.pinklocal forwards = colors.blacklocal backwards = colors.whitelocal digblocks = colors.blue------------------------------------function noOutput()rs.setBundledOutput(cableside, 0)end------------------------------------function move(direction, amount, bBreak)amount = amount or 1bBreak = bBreak or falsefor i=1,amount do if bBreak == true then rs.setBundledOutput(cableside, digblocks) sleep(0.1) end rs.setBundledOutput(cableside, direction) sleep(0.1) noOutput() sleep(1.8)endend------------------------------------function moveTo(x, y, z)local xc, yc, zc = gps.locate(3)local xm = x-xclocal ym = y-yclocal zm = z-zcif xm > 0 then move(backwards, xm)elseif xm < 0 then move(forwards, -xm)endif ym > 0 then move(up, ym)elseif ym < 0 then move(down, -ym)endif zm > 0 then move(left, zm)elseif zm < 0 then move(right, -zm)endend------------------------------------function dig(blocks)while true do move(left, blocks-5, true) move(down, 1, true) move(right, blocks-5, true) move(down, 1, true)endend------------------------------------while true dolocal input = read()if input == "dig" then write("size=") local size = read() dig(size*6)elseif input == "moveto" then write("x=") local tx = read() write("y=") local ty = read() write("z=") local tz = read() moveTo(tx, ty, tz)endshowInfo()end------------------------------------shell.run('clear')

just an fyi to the OP the gps prgram does not use Triangulation because Triangulation uses angles to find its distance to whatever you are using. computers cant get the angles from point a to b and Triangulation requires 3 nodes. the GPS program that is in computercraft uses Trilateration which uses 4 nodes and does not require angles at all but uses math to find a position using straight distance from one point to another.

http://en.wikipedia.org/wiki/Trilateration

BigSHinyToys, on 29 August 2012 - 12:50 PM said:

This is a Experimental and possibly bug riddled code

GPS builder turtle program.

This program sends a turtle up as far as it can go then builds a GPS cluster

Instructions < Reed

[WARNING] This is experimental code there are probably bugs and errors in it you may loose items when using this. I give no Warner to this code. use at your own risk

if you already have working GPS in your world DON'T USE THIS it will cause you a Big problems

I would recommended tying this out in a New creative world before using it in a real survival world so you know what is does.

place a turtle can be mining or normal WIFI not required.

place turtle with a clear path to the sky (no trees or obstacle above it)

add 600 fuel (one bucket of lava is 1200)
add 4 computers to slot 1
add 4 wifi modems to slot 2
If you are using a Mining turtle then you only need one disk drive in slot 3 and you will get it back. if you are not using a mining turtle then you will need four disk drives in slot 3
place a BLANK disk in slot 4

RUN this program.

Spoiler

if not turtle thenprint("Error Not turtle")returnendif turtle.getFuelLevel() < 600 thenprint("600 fuel is required")returnelseprint("Please Place 4 computers in slot one")print("4 modems in slot two")print("Disk drive in slot three")print("and boot disk in slot four")print("press Enter key to continue")while true do local event , key = os.pullEvent("key") if key == 28 then break endendprint("Launching")endlocal set = {}set[1] = {x = 0,y = 3,z = 255}set[2] = {x = 3,y = 0,z = 252}set[3] = {x = 0,y = -3,z = 255}set[4] = {x = -3,y = 0,z = 252}while turtle.up() doendfor a = 1,4 dofor i = 1,2 do turtle.forward()endturtle.select(1)turtle.place()turtle.back()turtle.select(2)turtle.place()turtle.down()turtle.forward()turtle.select(3)turtle.place()turtle.select(4)turtle.drop()-- make disk cusromfs.delete("disk/startup")file = fs.open("disk/startup","w")file.write([[fs.copy("disk/install","startup")]])file.close()file = fs.open("disk/install","w")file.write([[shell.run("gps","host",]]..set[a]["x"]..","..set[a]["y"]..","..set[a]["z"]..[[)]])file.close()-- end make disk customturtle.turnLeft()turtle.forward()turtle.up()turtle.turnRight()turtle.forward()turtle.turnRight()peripheral.call("front","turnOn")turtle.down()turtle.suck()turtle.select(3)turtle.dig()turtle.up()peripheral.call("front","reboot")turtle.turnRight()for i = 1,3 do turtle.forward()endturtle.turnLeft()turtle.forward()if a == 1 or a == 3 then for i = 1,3 do turtle.down() endelseif a == 2 or a == 4 then for i = 1,3 do turtle.up() endendendwhile turtle.down() doend

press Enter when you have it set up correctly and it will fly up into the sky place Computers turn them on and comeback down.

There is no back door into the computers so ounce they are up there they are staying there you can edit there code after this.

all going well your turtle returns with the disk to ground level. Report bugs here and I will hunt them down.

I just tested this in my ssp, it isn't rebooting the computers.

Um, I think I found an error, (feel free to troll me if i'm wrong).

But isn't the Y coordinate the vertical coordinate?
Then this would make Z north to south…

I've changed your code a little bit to allow for the minecraft coord system. Because of my very limited coding experience the turtle has to be facing west for the coords to be correct. It will prompt you for the x and z coords first before launching, Tell me what you think :)/>

http://pastebin.com/kiSuDf0Z

usmc3891, on 04 January 2013 - 12:41 PM said:

I've changed your code a little bit to allow for the minecraft coord system. Because of my very limited coding experience the turtle has to be facing west for the coords to be correct. It will prompt you for the x and z coords first before launching, Tell me what you think :)/>

http://pastebin.com/kiSuDf0Z

just tried this Pastebin I am not sure where its going wrong it starts to launch after fuel filling it up etc it just moved 2 blocks forward and places a computer and then backs up places a modem on the grass and then sits there.

i am in a mystcraft age if this matters or not?

Edit: himm must have been because it was raining i re-ran this a 3rd time in sunshine daytime and it worked.

BSH, thanks for this tutorial mate, really helped clear things up for me!

One observation with the GPS program, I think there may be an offset error with z (vertical):

I launched the turtle from a level where my feet position (y) shows as level 64. However once I've seeded the gps and place a computer/turtle at the same place I launched from, I get a z-coord of 65. If I go down to the lowest bedrock level (i.e only one bedrock block between me and void) feet loc shows as 1 whereas GPS z shows as 2.

Either this is an offset error, or the feet pos in the minecraft debug gives the coord of the block below the feet.

DrCeph, on 07 January 2013 - 08:13 PM said:

BSH, thanks for this tutorial mate, really helped clear things up for me!

One observation with the GPS program, I think there may be an offset error with z (vertical):

I launched the turtle from a level where my feet position (y) shows as level 64. However once I've seeded the gps and place a computer/turtle at the same place I launched from, I get a z-coord of 65. If I go down to the lowest bedrock level (i.e only one bedrock block between me and void) feet loc shows as 1 whereas GPS z shows as 2.

Either this is an offset error, or the feet pos in the minecraft debug gives the coord of the block below the feet.

looks like turtles can go to the highs block location or the lowest for some reason correction made to code thanks for pointing that out.

GPS Builder ALPHA v0.2 http://pastebin.com/gLTwfr8V

Niederlenz, on 07 February 2013 - 11:50 PM said:

How do I get the coords of my turtle like this?

There is a program that CC comes with called "gps" to Quote the help file from it

gps can be used to host a GPS server over rednet, or determine a position using trilateration.
Type "help gpsapi" for help using GPS functions in lua programs.

ex:
"gps locate" will connect to nearby GPS servers, and try to determine the position of the computer or turtle.
"gps host" will try to detemine the position, and host a GPS server if successful.
"gps host 10 20 30" will host a GPS server, using the manually entered position 10,20,30.

Take care when manually entering host positions. If the positions entered into multiple GPS host
are not consisent, the results of locate calls will be incorrect.

if you want to get that information from inside a program you can use the gps api to quote the help files.

Functions in the GPS API:
gps.locate( timeout )

The locate function will send a signal to nearby gps servers, and wait for responses before the timeout. If it receives enough responses to determine this computers position then x, y and z co-ordinates will be returned, otherwise it will return nil. If GPS hosts do not have their positions configured correctly, results will be inaccurate.

ChunLing, on 03 August 2012 - 08:47 PM said:

The GPS api itself doesn't do anything other than figure out positions based on existing positions, but your turtles can also act as GPS hosts themselves once they get their own positions. Because they can also transmit rednet wireless messages, it means that you could have all the turtle positions sent back to a central console from which you can see where they all are, and could even give them new orders on the fly (so to speak).

You could set up a monitor that shows the positions of all your turtles on a map of sorts.
would look awesome!