Difference between revisions of "Gps (API)"

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m (<nowiki> goes *around* the `[`s. Also, greetings IRC from the middle of nowhere!)
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<tr><td style="width: 100px; background: #E0E0E0; padding: .4em; font-weight:bold;">Return</td><td style="width: 350px; background: #E0E0E0; padding: .4em; font-weight:bold;">Method Name</td><td style="background: #E0E0E0; padding: .4em; font-weight:bold;">Description</td></tr>
 
<tr><td style="width: 100px; background: #E0E0E0; padding: .4em; font-weight:bold;">Return</td><td style="width: 350px; background: #E0E0E0; padding: .4em; font-weight:bold;">Method Name</td><td style="background: #E0E0E0; padding: .4em; font-weight:bold;">Description</td></tr>
  
<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">({{Type|int}} x, {{Type|int}} y, {{Type|int}} z), or [[nil]]</td>
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<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">({{Type|number}} x, {{Type|number}} y, {{Type|number}} z), or [[nil]]</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">gps.locate(<nowiki>[</nowiki>{{Type|float}} timeout [, {{Type|boolean}} debug]])</td>
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<td style="border-top: solid #C9C9C9 1px; padding: .4em;">gps.locate(<nowiki>[</nowiki>{{Type|number}} timeout [, {{Type|boolean}} debug]])</td>
 
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Tries to retrieve the computer or turtles own location. On success, returns the location of the turtle’s modem. On failure (if no responses are received for <var>timeout</var> seconds, by default 2), returns [[nil]]. If <var>debug</var> is <code>true</code>, debug messages are printed.</td></tr></table>
 
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Tries to retrieve the computer or turtles own location. On success, returns the location of the turtle’s modem. On failure (if no responses are received for <var>timeout</var> seconds, by default 2), returns [[nil]]. If <var>debug</var> is <code>true</code>, debug messages are printed.</td></tr></table>
  

Revision as of 00:55, 12 July 2013

The GPS API provides a method for turtles and computers to retrieve their own locations.

It broadcasts a PING message over rednet and wait for responses. In order for this system to work, there must be at least 4 computers used as gps hosts which will respond and allow trilateration. Three of these hosts should be in a plane, and the fourth should be either above or below the other three. You can set up hosts using the gps program.

Note: When entering in the coordinates for the host you need to put in the x,y,z of the computer, not the modem, as all rednet distances are measured from the block the computer is in.

Grid disk.png   Gps (API)

ReturnMethod NameDescription
(number x, number y, number z), or nil gps.locate([number timeout [, boolean debug]]) Tries to retrieve the computer or turtles own location. On success, returns the location of the turtle’s modem. On failure (if no responses are received for timeout seconds, by default 2), returns nil. If debug is true, debug messages are printed.

Example

 print("Man I am so lost right now!")
 local x, y, z = gps.locate(5)
 if x == nil then
   print("Nope, still lost :(")
 else
   print("I am at ",x," ",y," ",z)
 end

Vector Example

GPS position and navigation can be handled more easily using a vector.

 local home = vector.new(45, 85, 20)
 local position = vector.new(gps.locate(5))
 local displacement = position - home
 
 print("I am ", displacement.tostring(), " away from home!!!")


code>true