Even something as simple as having an accessory for the Universal Module so it can tell AHP if the garage door is opened or closed
It's not an accessory specifically for the Universal Module per se, but you can use a PowerFlash module to tell AHP whether a set of contacts is open or closed over the power line.
https://www.x10.com/psc01-powerflash-burgular-alarm-interface.htmlIn mode 3, it sends ON when the contacts close and OFF when they open.
A couple of things to note, however: (Aren't there always?)
- You'll have to design your own smart macros or other scheme to make use of these commands.
- The PowerFlash uses a non-polite transmitter, so the transmission could collide with another transmission sent at the same time and result in corrupt or no data received.
You could use an XPT3 instead, which is a polite transmitter and waits until the line is clear and then retransmits until successful. However, the XPT3 is meant to be hardwired in a wall box rather than plugged into an outlet, and you'll need either double-throw contacts on your door switch or two door switches, one normally open and one normally closed. (The XPT3 requires one wire to be shorted to common for an ON signal and a different wire shorted to common for an OFF signal.)
https://www.x10.com/xpt3.htmlI share all your sentiments regarding the RF issues. The RF protocol was not implemented with handling of retransmissions, acknowledgements, or programmed hops in mind, making it difficult to extend without side effects. I'd like to see those features better accommodated, but I don't know if there is a way to do it and keep it backward compatible. And if you start talking about designing a communication protocol, you may as well jump to Insteon or Z-Wave, which have already done that and had years to work out the bugs.