Re: Water heater eating X-10 signal

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>I see.  IIUC, the X-10 signal's frequency (120KHz?) is way outside the
>normal audio range so eventual success is going to depend a lot on the
>characteristics of the sound card and recording software.

OK, I have the prototype running. It does show the 140kHz noise, even at the
lowest (8Ks/s) sampling rate although with no detail at that resolution.
Still, it's an indication that there's something on the line that needs
further investigation. I'm not sure we need the resistors so it might get
even simpler and a bit cheaper.

I've added a screenshot showing a section of the .WAV file at...

     http://davehouston.net/ESM1-TEST.htm

A 10 hour .WAV file is about 2.2GB so I'm not sure it's all that useful for
overnight recording but it's also possible to design a small PIC-based
module to plug in instead of the soundcard with enough smarts to output just
the X-10 bits via RS232 so a 10 hour file becomes much smaller and much
easier to decipher. I was discussing adding RS232 output to the ESM1 with
Paul Beam (the designer) before ELK bought the rights to it. I sure wish I
had thought of this then.

Damn - that 60Hz hum (ZC squarewave) from my PC speaker is starting to annoy
me. You can also hear the X-10 bursts so this may prove to be a handy
troubleshooting tool.

I have to get my network back up before I can finish documenting things. I
have pictures of the ESM1 board with the added cable but my camera software
is on a different machine from my graphics editing software and HTML editor.