@stan2004 posted:But who/what controls the Master? By "co-located" is this just physical location or is there any "software" interaction between the 2.4 GHz radio network and DCS... for example at the Wi-Fi level. Note that to turn on a newly powered engine (e.g., on a siding) in the silent state and in Command mode, you don't need to generate the Watchdog packet itself. ANY DCS activity during the first few seconds will tell a newly powered DCS engine to start up silent and in Command mode. The Watchdog is essentially a benign placeholder command that doesn't do anything (doesn't change speed, doesn't blow horn, etc.) other than tell a newly powered engine that this is a Command control environment so be quiet and wait for further instructions.
This idea of "manually" creating DCS activity during the first few seconds of turning on a siding was discussed early on in the thread - some 5 years ago! It just seems that with all those Arduino's there ought to be some way to "hack" into the WIU to tell the TIU to issue some benign DCS activity whenever a new siding is powered.
Another scheme discussed early on required Arduino-type smarts (which you have). Why not have the Arduino generate the watchdog or whatever suitable DCS activity and put it on the track. There are issues with this which you can review but I regurgitate it for the sake of completeness or potentially stimulate additional what-ifs.
But I think your Plan B is the way to go - since your Master knows when it is turning on a siding, simply add a relay to momentarily interrupt the passively applied power to Fixed 1. Since the TIU is passively powered, the engines will not see the power interruption so they are none the wiser. It's only if the power interruption somehow confuses the TIU such as whatever information it has about Active Engines or whatever. But this momentary power-interruption method was what GRJ proposed in his original post so I think the most logical next step.
Stan,
Wow, a lot to think about and digest. I'll start with the Master Arduino. It's directives come from a keypad mounted on the control console or via Bluetooth from an Android tablet. When I first built the layout there were four rows with five columns of the Atlas 2 position switches wired to the switches on the layout along with accessories and sidings. Talk about a wad of wires. So if I wanted to throw Node 1 Switch 1 on the mainline, I'd toggle switch R1C1. Now I input 11 on the keypad or tablet and press send. It was the easiest way I could think of not having to re-learn a new number schema.
'Co-located' references physical location, both the Master and TIU reside in the same cavity at the master console with the WIU on top. So physical wiring / interconnection is not a problem. The main point of converting to wireless was to minimize the wired connections between the console and the layout.
There is currently no direct interaction between the radios and DCS. I've only very recently started to dip my toes in the Arduino / Legacy pond and have a very large amount of knowledge to learn. One place I fall really short right now would be with the WIU and how it interfaces with the tablet. From everything I've read on the Forum it seems MTH never released the protocols for DCS unlike Lionel has for TMCC / Legacy. Needless to say a 'hack' between the Master and the WIU or TIU would be the perfect solution. Just not sure how I get to there from here.
I tend to agree with your assessment regarding Plan B. Since I'm still in the process of converting the layout to wireless, it's not really operational at the moment. I will try to come up with some kind of test bed to check on the Fixed 1 momentary interruption. I think where my brain is at regards the timing around an engine on the inactive list being powered up, moving to the active list and some form of DCS command being issued for that specific locomotive.
Your and John's PWB is also an attractive solution.
As always Stan, I appreciate your (and all on the Forum) input.
Thanks, Barry
