@JD2035RR: "Something like this in kit form would be a fun project to involve older kids (teens) into the hobby while introducing them to electronic engineering and software coding."
I agree! Just before I sat down here my wife was encouraging me to put together a course (I have a background in education). I may do it. There are online forums like Great Courses Plus where a short course with labs could work. I'm also thinking about laying out some PCBs for manufacture for what I've worked up because a time consuming effort for me has been routing and soldering all the little wires on the solderable perf boards I use. If you know someone who does small batch PCBs please let me know. I've only begun to look.
>>> does the radio signal emit from the phone/device?
A more general answer before offering my specifics. Your handheld device needs to be able to access my home network. As I mentioned above if I poked a hole in my home network firewall you could get to my internal Web server by surfing to my IP address through your Web browser and you'd be off and running. Right now you have to be in the house and access my Web server through my wireless network. By accessing the proper name for the server (IP address) on my home network you gain access to the webpages I showed in my previous post. The Web server connects through software to a packet radio. Commands you issue through the Web interface are sent out through back end software for the Web server through an attached packet radio to my engines. The Web server software I wrote can run on most any popular computing platform. It's not as complex as it may initially sound and I'll be making my software available on Github in the near term.
My Web server and its backend software are all implemented on a $30 Raspberry Pi 3 with an attached packet radio. The RPi is attached to my home network. So it serves up control webpages to anyone accessing it through a browser (as depicted in my previous post), sends the commands to backend software I wrote in Python, which in turns sends the commands on to my engines. So one platform, the RPi, sits between your handheld and my engines. The webpages could be hosted on your home PC, as long as you had a way to connect your PC to a device with a packet radio. That's easily done through USB to, say, one of the Adafruit Feathers with a packet radio on board. Here's the Raspberry Pi 3 with a packet radio daughter board ("HAT"). It's connected to my home network and power only. It communicates (Webpages) with my handheld device and sends commands to all of my engines.
>>> I would like to hear more about the radio controlled switch modules.
Sure. As with the engine control, there's one device -- I'm calling it the switch master-- that has a packet radio that acts as the distributor of commands to a set of remote modules (in this case "switch nodes" rather than engine control modules). The switch master receives commands from my desktop computer via USB right now, but that could be changed to most any other source. It sends a command on to the correct switch module, and waits for an ACK back to ensure the command was received and acted upon. The switch master could just be one of the Adafruit Feather M0's with a packet radio attached (See my original post for the one I used in engine control modules). Because I had a handful of Adafruit "Itsy-Bitsys" around ($14 each) I bought separate packet radio boards ($10) and drive them from the Itsy Bitsys. Total cost ($24) is essentially the same as for the Feather M0 with on board packet radio ($25). Here's my first switch master ($24):
And here's a switch node that sits out by a cluster of switches:
Again, the switch node is using an Itsy Bitsy and separate packet radio board. The Feather M0 with packet radio on board I used in my engines could be used instead. To avoid using up all of the I/O pins on the Itsy Bitsy I bought a $5 mux/demux board from Sparkfun and can control 16 switch operations with five output lines from the Itsy Bitsy (4 channel select and 1 signal). Right now I'm using DZ1000's on my switches. They require about 14 VAC. So I bought the board of relays you see in the image ($14). If I decide to switch to DC controlled switch motors like the Tortoise I should be able to drive the switch operations through NPN FETs instead. To be determined.
What you see above is all built out and tested. The 16 gauge wire I'll be using to run 14VAC out to the switch nodes arrived on my doorstep about an hour ago. I'll use a bridge rectifier with smoothing cap to produce DC, and step it down to 12VDC (for the relays switching) and 5VDC to Itsy-Bitsy, radio and mux power using a couple of LM2596 Buck converters for. If I switch over to DC switch machines that setup would be simplified (12 VDC on the bus instead and one Buck converter for the 5VDC.)
>>> Which brand / model of projector are you using?
I've got a couple of DBPower projectors gotten off Amazon. There are a bunch of brands out there starting at about $40. Be sure to get one with vertical keystone correction since you'll want to mount them up high and aim down somewhat towards your projection surface. If you watched my video in my preceding post you can see I've got a lot of projection surfaces. And I have a lot of images I plan to project. I'm not into building trackside models and scenes much, at least on my mainline. My plan is to project scenes that can take you across the country, using careful fading and reuse of projection surfaces to create a convincing effect.
Ultimately my trains will be automatically dispatched. I'm a computer scientist. I read papers about how the big railroads avoid collisions and deadlock. I've kept up with the development of Positive Train Control (PTC). My plans for my auto dispatcher will take an arbitrary schedule and run the trains, deadlock and collision free, on schedule if it's feasible.
Again, I heartily agree with you @JD2035RR. These kinds of electronics re very attractive to students and trains offer an excellent platform on which to experiment with control, audio, video...
I'm happy to address any further questions.
The problem with retirement is there's just not enough time.
