17 posts
Posted 25 October 2016 - 10:21 AM
Does anyone know how to code detector rails and see which direction a train is coming from?
Also would I need APIs?
Also would I need APIs?
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RC detector rails and computers
Started by jkwok678, 25 October 2016 - 08:21 AM
2427 posts
UK
Posted 25 October 2016 - 03:16 PM
a pair of detector rails, with some gap between them, both have a separate redstone connection to the computer. Which redstone signal activates first tells you the direction the train is coming from.
17 posts
Posted 25 October 2016 - 06:26 PM
How would I code it? I'm trying to get the computer to wait for an input.
I tried this, but I can't get it to work. I think it's a logic error, also I can't seem to be able to output redstone signals to front and back.
The end goal is to connect it to make automatic signals
I tried this, but I can't get it to work. I think it's a logic error, also I can't seem to be able to output redstone signals to front and back.
The end goal is to connect it to make automatic signals
while true do
local right= rs.getInput("right")
local left= rs.getInput("left")
if right == "true" then
print(something)
if left == "true" then
print(something)
end
end
Edited on 25 October 2016 - 04:57 PM
3057 posts
United States of America
Posted 25 October 2016 - 06:58 PM
You don't have compare boolean values (true/false) at all to use them in an if statement (and you certainly shouldn't compare them to strings). Your code might look something like this:
while true do
local right = rs.getInput( 'right' )
local left = rs.getInput( "left" )
if right then
print( "There is a signal from the right" )
end
if left then
print( "There is a signal from the left" )
end
end
17 posts
Posted 25 October 2016 - 08:34 PM
So would it continually check for redstone signals? If not how would I make it so that it will?
I would like to connect the computers to railcraft signals, so how could I use another computer further on, to receive data from here. For example my train passes point A and the signal there goes red, then it passes point B and that turns red, and at the same time the signal at A is switched back to green, I know I can probably do this with on/off states of redstone, but how can i pass data around, do I need modems?
I would like to connect the computers to railcraft signals, so how could I use another computer further on, to receive data from here. For example my train passes point A and the signal there goes red, then it passes point B and that turns red, and at the same time the signal at A is switched back to green, I know I can probably do this with on/off states of redstone, but how can i pass data around, do I need modems?
Edited on 25 October 2016 - 08:19 PM
54 posts
Italy
Posted 25 October 2016 - 09:42 PM
If you want to pass data between computers, you do need modems, either wired or wireless.
17 posts
Posted 25 October 2016 - 11:00 PM
So would I need to use the modem API? How would I receive the data from the receiving computer and use that piece of data? how could I use this with RC signals?
If you want to pass data between computers, you do need modems, either wired or wireless.
3057 posts
United States of America
Posted 26 October 2016 - 12:45 AM
You would use the rednet API - specifically rednet.open, rednet.send and rednet.receive. I think send and receive are clear enough; open just tells the API which side the modem is attached.
I'm not sure what 'RC' signals are, I don't think they exist in computercraft. Were you perhaps asking about rednet or redstone?
It will, because it has an infinite loop. However, you should add
I'm not sure what 'RC' signals are, I don't think they exist in computercraft. Were you perhaps asking about rednet or redstone?
So would it continually check for redstone signals? If not how would I make it so that it will?
It will, because it has an infinite loop. However, you should add
os.pullEvent("redstone")
17 posts
Posted 27 October 2016 - 12:56 AM
So now that I have this, it's not fool proof, because a mine cart can run over both detectors and both outputs will happen, so how could I make sure only the first red stone signal from the detector is used. Also lets say I have another setup later on the mine cart line, with the two computers getting info with red net. How could I send a signal from the second detector back to the first to start that program again
Edited on 26 October 2016 - 10:58 PM
2427 posts
UK
Posted 27 October 2016 - 06:43 PM
how are your rails set up? if it's a single line then two trains would mean a crash (if it doesn't then reconfigure your track)
I would have the computer listening for a pair of signals to work out the direction of the train.
I would have the computer listening for a pair of signals to work out the direction of the train.
Edited on 27 October 2016 - 04:43 PM
17 posts
Posted 27 October 2016 - 09:03 PM
At the moment there are 4 detectors between detector 2 and 3 is a block, so a space for one train, so they won't crash into each other. What I want is for when the train passes the first detector the computer will notice the redstone current and will will switch on the redstone for front side and turn the signal to red. Then once it passes the 3rd detector, it will send a signal to the first computer telling it to turn the redstone at the front off. Does the code look OK?
So this is the code for the computer the first set of detectors
For computer at second set of detectors
So this is the code for the computer the first set of detectors
--this computerID is 202
rednet.open("back")
while true do
local right = rs.getInput("right") -- detector 2
local left = rs.getInput("left") -- detector 1
local next_comp = rednet.receive(1)
print(next_comp)
if right then
print("Train coming from right")
elseif left then
print("Train coming from left")
rs.setOutput("front",true) --set signal to red
elseif next_comp=="clear" then
rs.setOutput("front",false)-- set signal to green
end
os.pullEvent("redstone")
end
For computer at second set of detectors
--this computer ID is 183
rednet.open("back")
while true do
local right = rs.getInput("right") -- detector 4
local left = rs.getInput("left") -- detector 3
if right then
print("Train coming from right")
elseif left then
print("Train coming from left")
rednet.send(202,"clear")
end
end
os.pullEvent("redstone")
Edited on 28 October 2016 - 09:11 AM
54 posts
Italy
Posted 28 October 2016 - 05:42 PM
Because of the os.pullEvent("redstone"). It simply stops the code until redstone changes - but you want to do something also when a rednet message is recieved.
You can simply delete the parameter - it will run the code for every event it listens, but it should work fine.
Also, in the second code, that pullEvent should be before the last end, it won't work otherwise. Now, after that the while loop terminated, the computer will wait for a redstone event - you wanted instead to wait for a redstone event for restarting the while loop.
You can simply delete the parameter - it will run the code for every event it listens, but it should work fine.
Also, in the second code, that pullEvent should be before the last end, it won't work otherwise. Now, after that the while loop terminated, the computer will wait for a redstone event - you wanted instead to wait for a redstone event for restarting the while loop.
17 posts
Posted 29 October 2016 - 10:20 PM
For some reason this computer with the first code still doesn't switch the signal at the front of the computer.
This is the code for the first computer. I think it's the first computer not receiving the signal because the front redstone of the second computer lights up but the both computers are wired by a modem on the back
This is the code for the first computer. I think it's the first computer not receiving the signal because the front redstone of the second computer lights up but the both computers are wired by a modem on the back
--ComputerID is 202
rednet.open("back")
while true do
local right =rs.getInput("right")
local left = rs.getInput("left")
local next = rednet.receive()
if left then
rs.setOutput("front",true)
elseif right then
print("right")
end
if next=="clear" then
rs.setOutput("front",false)
end
end
--ComputerID is 183
rednet.open("back")
while true do
local right =rs.getInput("right")
local left =rs.getInput("left")
if left then
rs.setOutput("front",true)
rednet.send(202,"clear")
elseif right then
print("right")
end
os.pullEvent("redstone")
end
Edited on 29 October 2016 - 08:41 PM
7083 posts
Tasmania (AU)
Posted 30 October 2016 - 12:29 AM
Remember that rednet.receive() returns multiple values - first the sender ID, then the message.
local sender, next = rednet.receive()
17 posts
Posted 01 November 2016 - 06:57 PM
Is there a way for example to make the if statements choose the path based on the direction of travel for example if left detector is activated and then right detector is activated it will do something?
2427 posts
UK
Posted 01 November 2016 - 10:05 PM
Is there a way for example to make the if statements choose the path based on the direction of travel for example if left detector is activated and then right detector is activated it will do something?
if left restone then
start a timer
exit = false
while not exit do
event = os.pullEvent()
if event is timer then
print("one signal")
exit = true
elseif event is redstone
if right redstone then
print("signal pair")
exit = true
end
end
end
end
Edited on 01 November 2016 - 09:07 PM
17 posts
Posted 02 November 2016 - 04:40 PM
I was thinking of more like this
This is kinda pseudo code
This is kinda pseudo code
if "left detector activates and then right detector activates"
print "cart is from left"
if "right detector activates and then left detector activates"
print "cart is from right"
2427 posts
UK
Posted 02 November 2016 - 06:13 PM
my code does that but only for one side, you can copy-paste and edit to do right to left
17 posts
Posted 05 November 2016 - 12:19 PM
I have no idea how to incorporate the earlier code into this one of sending red stone signals forward and backwards with the new conditions.
Currently neither of them work properly
--ComputerId is 202
rednet.open("back")
while true do
local right =rs.getInput("right")
local left = rs.getInput("left")
local next = rednet.receive()
if left then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event == "timer" then
exit = true
elseif event=="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(183,"clear")
os.sleep(10)
rs.setOutput("back",false)
rs.setOutput("front",false)
exit = true
end
end
end
if right then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event == "timer" then
exit = true
elseif event =="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(183,"blocked")
exit = true
end
end
end
end
if message=="clear" and SenderID ==183then
rs.setOutput("front",false)
rs.setOutput("back",false)
end
Currently neither of them work properly
--ComputerId is 183
rednet.open("back")
while true do
local right =rs.getInput("right")
local left = rs.getInput("left")
local next = rednet.receive()
if left restone then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event=="timer" then
exit = true
elseif event=="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(202,"blocked")
exit = true
end
end
end
if right redstone then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event="timer" then
exit = true
elseif event=="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(202,"clear")
os.sleep(10)
rs.setOutput("back",false)
rs.setOutput("front",false)
exit = true
end
end
end
end
if message=="clear" and SenderID ==202 then
rs.setOutput("front",false)
end
2427 posts
UK
Posted 05 November 2016 - 12:39 PM
indentation should line up with scope, this makes code more readable
also error codes help
rednet.recive is like a specialized pull event
if left redstone then is not valid lua
also error codes help
rednet.recive is like a specialized pull event
if left redstone then is not valid lua
Edited on 05 November 2016 - 11:42 AM
17 posts
Posted 05 November 2016 - 08:13 PM
This is the code fixed up a little, but right now it's a logic error, I'm trying to merge the the redstone opening and closing and the directional detector
--ComputerId is 202
rednet.open("back")
while true do
local right =rs.getInput("right")
local left = rs.getInput("left")
local next = rednet.receive()
if left then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event == "timer" then
exit = true
elseif event=="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(183,"clear")
os.sleep(10)
rs.setOutput("back",false)
rs.setOutput("front",false)
exit = true
end
end
end
if right then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event == "timer" then
exit = true
elseif event =="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(183,"blocked")
exit = true
end
end
end
if message=="clear" and SenderID ==183 then
rs.setOutput("front",false)
rs.setOutput("back",false)
end
end
--ComputerId is 183
rednet.open("back")
while true do
local right =rs.getInput("right")
local left = rs.getInput("left")
local next = rednet.receive()
if left then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event=="timer" then
exit = true
elseif event=="redstone" then
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(202,"blocked")
exit = true
end
end
end
if right then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event="timer" then
exit = true
elseif event=="redstone" then
print("signal pair")
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(202,"clear")
os.sleep(10)
rs.setOutput("back",false)
rs.setOutput("front",false)
exit = true
end
end
end
if message=="clear" and SenderID ==202 then
rs.setOutput("front",false)
end
end
7083 posts
Tasmania (AU)
Posted 05 November 2016 - 11:45 PM
What does the code currently do, and how does this actually differ from what you want it to do?
17 posts
Posted 07 November 2016 - 06:10 PM
At the moment, in the second code it first checks for an redstone input on the right and left, if it's from the left it will start a timer, if within that timer, there is another redstone input from the right then it means that the train is coming from the left, next the computer will output two redstone signal (front and back) that will turn the signals going forward and backwards to red at this point. It will also send the next computer in line blocked so that, that computer will switch the backwards signal to red, then when the train passes the second signal in front, the computer will send a signal back to the first telling it to turn off the redstone at front and back to reset signals to green.
That is basically what I want to do but it doesn't seem to work, probably a logic error and it could be the conditions for finding out the direction of the train
That is basically what I want to do but it doesn't seem to work, probably a logic error and it could be the conditions for finding out the direction of the train
Edited on 07 November 2016 - 05:12 PM
2427 posts
UK
Posted 07 November 2016 - 07:40 PM
At the moment, in the second code it first checks for an redstone input on the right and left, if it's from the left it will start a timer, if within that timer, there is another redstone input from the right then it means that the train is coming from the left, next the computer will output two redstone signal (front and back) that will turn the signals going forward and backwards to red at this point. It will also send the next computer in line blocked so that, that computer will switch the backwards signal to red, then when the train passes the second signal in front, the computer will send a signal back to the first telling it to turn off the redstone at front and back to reset signals to green.
That is basically what I want to do but it doesn't seem to work, probably a logic error and it could be the conditions for finding out the direction of the train
This is really unclear, where are you saying what it currently does and where are you saying what you want it to do?
Repeating the questions separately:
- What does the code currently do? I.E. when it is running in game what happens?
- What are you wanting it to be doing? Focus on the things that it's not doing currently.
17 posts
Posted 08 November 2016 - 11:28 PM
Ok I'm getting confused as well, so I'm going to start again.
Does this code look right for just detecting the train coming from the left then Outputing redstone signals front and back if it is?
Does this code look right for just detecting the train coming from the left then Outputing redstone signals front and back if it is?
--First computer on the line ID 183
while true do
local left=rs.getInput("left")
local right=rs.getInput("right")
local senderID,message,protocol=rednet.receive(1)
if left then
os.startTimer(3)
exit = false
while not exit do
event = os.pullEvent()
if event =="timer" then
exit = true
elseif event is redstone
if right redstone then
rs.setOutput("front",true)
rs.setOutput("back",true)
rednet.send(202,"blocked")
exit = true
end
end
end
end
Edited on 08 November 2016 - 10:30 PM
2427 posts
UK
Posted 09 November 2016 - 09:33 AM
you need to call redstone.getInput("right")after the redstone event.
also, if right redstone then will error as it's not valid lua
also, if right redstone then will error as it's not valid lua
17 posts
Posted 09 November 2016 - 08:29 PM
Does it look alright? The logic is that, if a train comes from either left or right redstone outputs at front and back. Then if the train is coming from left send a message to the next computer to tell it that the line is "blocked". The other will tell that same signal that the line is "clear"
The code is there because formatting is really hard on here
http://pastebin.com/QGghZWQY
The code is there because formatting is really hard on here
http://pastebin.com/QGghZWQY
2427 posts
UK
Posted 09 November 2016 - 09:12 PM
the pastebin one looks fine, not the most efficient but I think it should work.
Have you tested it and does it do what you want it to do?
Have you tested it and does it do what you want it to do?
17 posts
Posted 12 November 2016 - 12:17 AM
No, I haven't tested it yet but I will do soon because for it to be complete, I would need the second computer program code.on.
How could I make this more efficient? I know that the code is very long right now
By utilising functions?
How could I make this more efficient? I know that the code is very long right now
By utilising functions?
2427 posts
UK
Posted 12 November 2016 - 12:50 PM
I'd get the whole system working before trying to get it more efficient.
17 posts
Posted 15 November 2016 - 06:37 PM
The code for the second computer: http://pastebin.com/3WQYSBt6
The code for the first computer: http://pastebin.com/QGghZWQY
There seems to be a logic error but I can't seem to spot it. There is no syntax error though.
The code for the first computer: http://pastebin.com/QGghZWQY
There seems to be a logic error but I can't seem to spot it. There is no syntax error though.
7083 posts
Tasmania (AU)
Posted 15 November 2016 - 09:19 PM
And you expect someone else to spot it, even if you don't explain the behavioural problem it's causing?
17 posts
Posted 17 November 2016 - 06:47 PM
I think it's the code that decides on the direction of cart because the code before worked and I only just copied the code that worked for turning on and off rs signals. So I think what I need is another way to do it, especially if there are two carts going after each other, in which the code that was shown to me wouldn't work