So first off I would just like tp introduce my self... Yes I realize that there is a thread for this but I decided just to combine it into one thread. I am a 14 year old who got into trains when every Christmas my grandpa got a out a basic oval track to put around the Christmas tree. In 2012 We decided that in my basement we would build a larger layout. We built the layout stuck a train on it and hey it worked. But it was just track, we added a few accessories (A small train house with a small led, a culvert loader & an unloader). We made plans to get a few more powered accessories as well as locking into getting scale decorations (trees, gravel, etc.). Before we actually got around to this my grandpa's health started declining and without him to push me forward (I was just barely 10 at the time) The project came to a halt. The room that it was in was a multi-purpose room. It was our network room, Gift wrapping room, as well as my robotics room and so the table the train layout was on got used mainly as a storage table meaning even if I wanted to just go down to run it would have taken an hour just to get stuff cleared off the track, so the train never go used. Fast forward 4 years and I decided that I am going to start working on it again. Now with new knowledge of electronics and how things in general work I have decided that I am going to make my own, Raspberry pi based, control system. I have done most of the grunt work (Cleaning up the room, getting the track into a basic working order, and then completely disassembling the current network of power cables the provide power to the track. Now I'm starting on the fun stuff (and the stuff I need the help of this board to problem-solve) So what I am currently doing is running each section of track it's own power line back to the "control station". I am also running accessory power to each switch so it can be operated regardless of track power. Then once I have everything run back to where it is easily manageable in one location on the track I will start adding in the new component. The idea is that I will have a normal electromechanical relay control board for each switch and possibly a solid state relay for each block of track. (1) This is the first problem I hit: How do I use a relay (or some other piece of hardware) to control the "large" amount of track power with the "small" amount of power from a raspberry pi and still maintain the ability to control the voltage (speed) of the train. The next part is direction and sound. I figured out pretty quickly, confirmed by a quick google search, that direction is changed just by a drop to zero in the voltage and then bringing it back up again. (2) The part I can't figure out is how my current train transformer/controller tells the train to sounds its bell/whistle. There is no voltage fluctuation that I could see use a multimeter and it doesn't have Lionel's tmcc controller on board. (3) The last problem I face is the software I love electrical engineering/playing with the hardware but I only know the basics to coding in any language and defiantly couldn't build the software that I have in mind. I would like something that is open-source and low to no cost. And although I'm not ruling anything out because of this, It would be nice to be able to send inputs ( button presses) to the software and have it respond accordingly so that way I could use a traditional interface combined with some form of computer system. I looked into JMRI but I wasn't sure if it would be able to control the relays from the GPIO pins of the pi (just to clarify the whole software doesn't need to be run from the pi it just needs to be able to accept inputs and transmit them to say a pc based system either way works). So just as a short recap or for those who don't prefer reading large blocks of text here are the problems I face: (refer to numbers in text for more details) Using a relay/other hardware to "dim" the tracks voltage (not just ON/OFF) How to trigger the Bell/Whistle function on train using the above method Software interface for the whole project Attached is a photo of the train layout design for anyone interested. I appreciate any help even if they are just untested ideas as I can always research and if nothing else just try it out.