stan2004 posted:I think there are 2 overlapping aspects to this conversation. 1) What it is, 2) How to do it. While there is a necessary and useful back-and-forth between the What and How, it seems threads like this get bogged down.
I believe the What needs to play out more. In other words, I for one would like to hear more ideas on What guys would want to do with control of rolling stock. I am 100% on-board with the original idea of sync'ing the directional or classification lighting of a slave/trailing engine to the master/lead engine. But I'm curious about other animation functions slaved to engine behavior...or that would make sense to be remotely-controlled via the engine.
Separately, there's How. As you've mentioned earlier, the challenge with the 99 cent "garage-door-opener" modules is how to shut up the transmitter so that the RF channel is available for other layout devices. This being in contrast to Bluetooth, Wi-Fi, or similar wireless modules/technologies that have the inherent ability to co-exist or play well with others. As you point out, what's neat about the so-called "learning" receiver module you found is the latching mode. This mode was not available on the original eBay 99 cent receivers. So with latching mode, you can send a short RF signal to turn on the back-up light and it latches on...and then minutes or hours later send a separate short RF signal to turn off the back-up light and it latches off. And for all the time between direction changes, the RF channel is available for other devices on the layout to do the same.
What's not clear to me is how a custom 50 cent microcontroller would play into a practical solution for the average O-gauger. Would this be a one-off proof-of-concept or would there be an actual order-able, no-soldering-required kit? Or something in between... like a link to a circuit board layout that one orders from OSH-Park and maybe a downloadable software image that runs on an Arduino Nano. I initially thought a rudimentary implementation would be some kind of discrete timer circuit (no software) that momentarily pulses the transmitter with the ON/Reverse command when it detects the engine's backup light turning on. The timer circuit would additionally momentarily pulse the transmitter with the OFF/Forward command when it detects the engine's backup light turning off. The receiver module would be set to the latching mode.
Stan, to be clear, I'm not complaining about your input, rarely do I see any issue with what you say. 
My concept is indeed to lay out two little support boards, one for each end. They would have the uP, input signal conditioning circuitry for the tranmitter, output drivers for the receiver, and of course, the power supply for the receiver or transmitter.
The uP is necessary, at least in my mind. If I'm triggering on something like the backup light coming on, the question arises as to how I terminate the transmission. Obviously, if we can come up with something with sufficient flexibility that doesn't require the uP, that would likely be a better plan, easier for anyone to build and use.
One reason I'm looking at extra circuits is in order to make this truly semi-universal, I believe you'll need opto isolation on the transmitter inputs. Given that many signals, especially on DCS and later Legacy, have no common ground, I wouldn't want to cause issues trying to tap into them. My vision if for stuff like lights, couplers, smoke, and of course I'd probably do one senses the motor voltage (motion sensing).
There would probably only be two or three transmit inputs by my way of thinking, but the purpose of this thread was to get some more input as to what people envision something like this unit being used for.
