So I spent all night working on a switch I can operate from inside my minecart at my three-way T-intersection on my elevated rail network. Took hours... but I finally got it working and that's pretty satisfying indeed. A lot of experimenting and learing about logic gates with redstone.
Basically I have a flat track at elevation 26 above sea level. Right before the T, on all three incoming legs, I drop down to elevation 25 for 2 blocks. In those blocks I put a downward (un)powered rail (to stop the cart). Next to the cart is a lever which I can use to switch the intersection either direction. And next to the lever is a button which powers up the rail I'm sitting on when I'm ready to go. The next section is standard rail which takes me back up to 26 and on thru the T.
On the first flat section after the little 2-block dip (but before the T), I put a detector rail and run redstone wire to the powered rail. This allows the cart to go right thru the other dip sections when I've cleared the T and am on my way. The cart doesn't stop on the way out, it only stops on the way in.
So I end up with three levers, and they needed to basically toggle the T in either direction. This was the real challenge. I ended up with two XOR logic gates in series. The first XOR takes the input from two of the switches and turns it into one output. This output then goes to one of the inputs on the second XOR. The second input is the third lever. This final output goes right under the T intersection itself, with a redstone torch to toggle it.
Basically, it doesn't matter if the T is powered or not. I just need to toggle it, so flipping any of the levers will switch the track the other way. That's what this all does.
I built the whole thing under the track directly below the intersection. It's pretty massive of course. LOL I first used the "F" XOR gate from the wiki. I got the whole thing working perfectly. But it was a mess. The thing was huge and deep too, almost reaching the ground. So I did more searching, and found another XOR that's only 1 block deep and 5 or 6 blocks tall. I took a deep breath (and groaned), and tore it all down and rebuilt it from scratch with the new XOR's. Took me hours... and it's still pretty massive but it works perfectly and this one is a keeper.
The next thing I need to do is figure out a system of lights to show which way the switch it pointing. I dunno how I'm gonna do this part, it's stumping me right now. I'm pretty much out of room for redstone since it seems you really have to be careful with adjacent blocks transmitting to others unintentionally. Obviously the signals will have to go over the rail somehow.
Haven't seen much discussion here of redstone, but it seems to be the biggest puzzle left in the game to figure out so that's gonna be my new focus. Since I'm adding the third leg now to my rail network, this was important for me to do.
Originally I wanted to flip a switch at the station to remotely select the switch at the T... but at this point I have no idea if that would ever work since I think I'd run into the "chunk issue" where the redstone signal wouldn't travel such a long distance and work in a distant chunk that isn't even loaded. That's a big project, too big for experimenting. Gonna have to go research more.
If anyone has questions, I'll see if I can try to help out. I have no idea how to get screenshots and post em on here, but not sure what it would really show you, except this massive 11x11 cobblestone box below my elevated rail that extends down about 7 or 8 blocks below the track, making a huge shadow on the ground. LOL Shadows are a problem, because I soon realized mobs don't burn up down there even tho the sun is shining. I finally just went to peaceful mode (I cheated) to finish it. haha
Oh, almost forgot... here's the XOR switch I used.
Basically I have a flat track at elevation 26 above sea level. Right before the T, on all three incoming legs, I drop down to elevation 25 for 2 blocks. In those blocks I put a downward (un)powered rail (to stop the cart). Next to the cart is a lever which I can use to switch the intersection either direction. And next to the lever is a button which powers up the rail I'm sitting on when I'm ready to go. The next section is standard rail which takes me back up to 26 and on thru the T.
On the first flat section after the little 2-block dip (but before the T), I put a detector rail and run redstone wire to the powered rail. This allows the cart to go right thru the other dip sections when I've cleared the T and am on my way. The cart doesn't stop on the way out, it only stops on the way in.
So I end up with three levers, and they needed to basically toggle the T in either direction. This was the real challenge. I ended up with two XOR logic gates in series. The first XOR takes the input from two of the switches and turns it into one output. This output then goes to one of the inputs on the second XOR. The second input is the third lever. This final output goes right under the T intersection itself, with a redstone torch to toggle it.
Basically, it doesn't matter if the T is powered or not. I just need to toggle it, so flipping any of the levers will switch the track the other way. That's what this all does.
I built the whole thing under the track directly below the intersection. It's pretty massive of course. LOL I first used the "F" XOR gate from the wiki. I got the whole thing working perfectly. But it was a mess.
The next thing I need to do is figure out a system of lights to show which way the switch it pointing. I dunno how I'm gonna do this part, it's stumping me right now. I'm pretty much out of room for redstone since it seems you really have to be careful with adjacent blocks transmitting to others unintentionally. Obviously the signals will have to go over the rail somehow.
Haven't seen much discussion here of redstone, but it seems to be the biggest puzzle left in the game to figure out so that's gonna be my new focus. Since I'm adding the third leg now to my rail network, this was important for me to do.
Originally I wanted to flip a switch at the station to remotely select the switch at the T... but at this point I have no idea if that would ever work since I think I'd run into the "chunk issue" where the redstone signal wouldn't travel such a long distance and work in a distant chunk that isn't even loaded. That's a big project, too big for experimenting.
If anyone has questions, I'll see if I can try to help out. I have no idea how to get screenshots and post em on here, but not sure what it would really show you, except this massive 11x11 cobblestone box below my elevated rail that extends down about 7 or 8 blocks below the track, making a huge shadow on the ground. LOL Shadows are a problem, because I soon realized mobs don't burn up down there even tho the sun is shining. I finally just went to peaceful mode (I cheated) to finish it. haha
Oh, almost forgot... here's the XOR switch I used.