[ERROR] event red net message detection

I'm attempting to create a red net based secret door; where one computer sends a specific red net message and the receiving computer sends a redstone signal to some pistons. When it receives a different message it stops the redstone signal. I want it to be able to receive the signal at any time. The code is located as the startup.

Finished code:
Startup code on computer #28

while true do
rednet.open("back")
Rednet1, Rednet2, Rednet3 = os.pullEvent("rednet_message")
print(Rednet1)
print(Rednet2)
print(Rednet3)
if Rednet3 == "open" then
redstone.setOutput("left", false
elseif Rednet3 == "close" then
redstone.setOoutput("left", true)
else
end
end

open_trap_door code on computer #21

rednet.open("left")
rednet.send(28, "open")

close_trap_door code on computer #21

rednet.open("left")
rednet.send(28, "close")

wrothmonk, on 19 March 2012 - 06:49 PM said:

I'm attempting to create a red net based secret door; where one computer sends a specific red net message and the receiving computer sends a redstone signal to some pistons. When it receives a different message it stops the redstone signal. I want it to be able to receive the signal at any time. The code is located as the startup.
CODE

while true do
rednet.open("back")
Rednet1, Rednet2, other1, other2, other3 = os.pullEvent()
if "red net_message", "open" = Rednet1, Rednet2 then
redstone.setOutput("left", false)
elseif "rednet_message", "open" = Rednet1, Rednet2 then
redstone.setOutput("left", true)
else
end

ERROR

bios:206: [string "startup]:4: 'then' expected

Use '==' instead of '='. I have that same error all the time too :D/>/>.

ty for pointing that out. However it still didn't fix the bug :D/>/>

missed one… although I'm getting another bug

CODE

while true do
rednet.open("back")
Rednet1, Rednet2, other1, other2, other3 == os.pullEvent()
if "red net_message", "open" == Rednet1, Rednet2 then
redstone.setOutput("left", false)
elseif "rednet_message", "open" == Rednet1, Rednet2 then
redstone.setOutput("left", true)
else
end

ERROR

bios:206: [string "startup"]:3: '=' expected

To many ='s in os.pullEvent() statements.

proper syntax with the = is:
a = 1
if a == 1 then

Should be(you probably dont need this many vars and would be better to use locals)

Rednet1, Rednet2, other1, other2, other3 = os.pullEvent()

For the first example anyway. I don't think the second method would work.

You also have some typo's and errors in your if statements.

I would personally do it like this

while true do
rednet.open("back")
local event, other1, other2 = os.pullEvent("rednet_message")
   if other2 == "open" then
	  redstone.setOutput("left", true)
   elseif other2 == "close" then
	   redstone.setOutput("left", false)
   end
end

event var - will get set as the event type
other1 var - will get set as the sending computer id
other2 var - will get set as the message

the os.pullEvent("rednet_message") filters out all other events except rednet_message

@wrothmonk:
= is used to assign a variable.
== is used for comparison.

Specifically in your code:
Use = for assigning variables to os.pullEvent(), but == if you want to compare them.

EDIT: Whoops, too late, got Ninja'd. :D/>/>

ok then. Heres the new code and error.
CODE

while true do
rednet.open("back")
Rednet1, Rednet2, other1, other2, other3 = os.pullEvent()
if "red net_message", "open" == Rednet1, Rednet2 then
redstone.setOutput("left", false)
elseif "rednet_message", "open" == Rednet1, Rednet2 then
redstone.setOutput("left", true)
else
end

ERROR

bios:206: [string "startup"]:4: 'then' expected

add two 'end's

updated original post code/error. Still having the same error as before though.
Also thank you liraal for pointing that out. I hadn't realized at first that I needed two ends. Makes sense with the if though.

Wow alot going on here… lol

Try the edit I put it.

ok tried your edit no errors popped up. However when I attempt to send a message using the close_trap_door code it doesn't do anything. I have update main post with all info.

check whether the messages get through at all. open the lua prompt and type os.pullEvent("rednet_message") is something pops up when you send the message, it's all good.

try doing a rednet.broadcast( "open" ) to see if it will pick that up. If so make sure you are using the correct id.

If not make sure the computers are in range and that the ports are opening.

@wrothmonk:
Case-Sensitivity is important not only in Lua code, but especially when using Strings.
E.g. you used "rednet_Message" with a capital M, but it should be lower-case.

ok broadcast didn't work. Can you tell me the range of the rednet? I also don't know how to check if the ports are opening.
@Espen: sorry that was a typo on the post. It is lower case in code. (now its updated in OP)

ah I figured out the problem. it turns out the message was not being received properly in luanub's.
Updated OP for any of those interested inthe working code.