Question for those using the CM11A for PC-based automation software

[JeffVolp]

I have a question for those of you who use the CM11A as a powerline interface for PC-based automation software.

I have been developing a RS232 serial port XTB powerline interface.  It is strictly a powerline interface, and does not repeat powerline commands.  To make this compatible with existing systems, it would emulate the “real-time” CM11A protocol.  It would not support any CM11A programmed functions, such as timers or macros.  It would strictly work as a powerline interface.

The CM11A serial port includes a Ring Indicator output to wake up a PC as it begins to receive a command.  My question is whether this signal is really needed for PC-based automation software.

The reason I ask is that I am at a quandary.  It just won't fit.  Adding the isolated serial port I/O takes too much PCB space, so I am looking for anything to reduce the size.  Eliminating the ring indicator allows using a smaller PIC, and also eliminates an opto-isolator and related passive components.  This may be just enough to let me squeeze everything onto the board.

If the ring indicator is needed, pretty much the only option is to go surface mount with components on both sides.  That takes this into a different assembly class, and eliminates any possibility of a kit version.

Jeff

[pconroy]

IIRC HeyU doesn't care about RI.

The half dozen times I've written something to control my CM11A, I've never cared about it either.
Personally I find the modem control lines (RTS, CTS etc) all more of a pain than value.

TX, RX and GND would be about the only ones I care about.

And - from what I've seen on the few USB/232 adapters out there, ignoring those non essential pins probably helps us out.

[Brian H]

I believe Active Home used the RI. Since yours is going to be a interface only. I doubt anyone would be using AH on it.

[JeffVolp]

Thank you for the info.

Jeff

[JeffVolp]

I managed to squeeze everything onto the board (no surface mount).  Prototype boards are on order.

Jeff

[JeffVolp]

I don't know about continuing this project.  As most of you know, the CM11A had been discontinued several years ago, and the remaining supply of new units has pretty much dried up.  Like with the XTBM, I started working this project to fill the gap.

Just yesterday I found out that a new batch of over 1000 CM11A's were manufactured several months ago, and they are available through a major eBay distributor.

Jeff

[Brian H]

Wow. X10 actually did a production run of CM11A's. For an EBay dealer.
Does sound like you may want to put the project on the shelf for now.

[Dan Lawrence]

Who's the EBay dealer for those who want a CM11A not for this project?

[Brian H]

Google found a few EBay vendors with the CM11A search line.
One said more than ten available. 

[JeffVolp]

One said more than ten available. 

How about 25 cases of 48?

Jeff

[Brian H]

Oh I missed the one selling cases of 48. 

Did a search directly on EBay and did find the vendor selling the cases of 48.

I also found an X10 dealer with 980 left. This morning.

[JeffVolp]

For anyone interested, here is a photo of the prototype.

Jeff

[-Bill- (of wgjohns.com)]

JeffVolp,
To coin a phrase (more or less )... This is obviously some strange usage of the word prototype that I wasn't previously aware of.   
Where's the perfboard?  Where are the unruly wires terminated in solder blobs that I know I should have reheated?   

"Prototype".      

[JeffVolp]

Years ago a prototype for me was a wire-wrapped board, but that doesn't work well for mixed signal circuits, especially where high currents or 120VAC are involved.  So a "prototype" now is a bare bones PCB without a solder mask or silk screen.  That also verifies the PCB layout to minimize the risk transitioning from the prototype to the first quantity PCB order.  A mistake there can be costly.  And there was one on this "prototype"  I had used the library SIP symbol for the programming header, and forgot to enlarge the holes from the PCB pins to the .025 square posts.

Jeff

[pconroy]

Nice!!!

Jeff - add a USB interface, keep the CM11A protocol and you'd be elected Grand Poobah in the HeyU Hall of Heroes!   






Heyu users still lament the fact there is no support for the CM15A.