Basic block detection

Hey there!

Complete novice here, so I understand that this is probably a very basic program!

I need to make a block detector that outputs a redstone signal when there isn't a block in front of it. I've tried the 'turtle.detect()' command but it didn't seem to work.

Thanks in advance.

turtle.detect should be enough for your needs, post the code you have so far so we can help you fix what isn't working.

Thanks for the reply,

I've literally just put this in https://imgur.com/a/yaq93

I'm a complete novice when it comes to this!

It's one thing to have the turtle detect a block, but if you want it to do something based on a block's presence, then you have to specify what that action's going to be.

turtle.detect() returns a boolean representing either true or false depending on whether a block is found in front of the turtle when it's called.

rs.setOutput() accepts a boolean, and uses it to either activate or de-activate a redstone signal from a given side of the turtle.

For example, we can activate a rear signal if a block is present by doing:

rs.setOutput( "back", turtle.detect() )

For the opposite (activating a signal when a block is not present), we can inverse the bool:

rs.setOutput( "back", not turtle.detect() )

Since you likely want the turtle to continuously check the space in front of it while updating the redstone signal accordingly, the line should be wrapped within a while loop:

while true do    --# Starts a loop that repeats indefinitely.
	rs.setOutput( "back", not turtle.detect() )
	sleep(1)   --# Wait a second before continuing.
end

That sounds like what I want, I just need it to send a signal when the space directly in front is empty so another block can be placed there.

https://imgur.com/a/7qa8F

Is this correct?

Looks good.

Thanks! This is working now!

How would I do this to make the redstone signal only activate for a single tick?

That's not much more complex. The same concepts apply, just slightly re-organised:

while true do
	while turtle.detect() do sleep(1) end  --# Wait until the front is clear.
	
	rs.setOutput( "back", true )
	sleep(0.1)
	rs.setOutput( "back", false )
	
	while not turtle.detect() do sleep(1) end --# Wait for the block to re-appear.
end

Note that there are "server" ticks (0.05s, a twentieth of a second), and there are "redstone" ticks (0.1s, a tenth of a second). If you change the state of a redstone signal more often than the redstone tick speed, whatever's at the end of the wire may not register that the state changed at all.

Thanks so much! This is exactly what I was looking for.

Thanks for your help!