Re: X-10 RF troubleshooting

[nobody@xxxxxxxxxxxx (Dave Houston)]

Yes, the BX24-AHT already gives an RSSI measurement - it's the [bracketed]
number in the RF output. It could control an LED but that would be such
heavy overkill as to border on being criminally insane. ;)

It would be possible to write a simple program for the BX-24 or ZX-24 to do
this and you could download it instead of the normal program then switch
back when finished. The users manual for the BasicX and ZBasic languages can
be downloaded from their respective web sites. Look at the "GetADC" and
"PutDAC" procedures. I think they even have simple schematics for "PutDAC"
in some app notes on the BasicX site. The BX24-AHT is not, however, amenable
to being battery powered.

A PIC12F675 makes more sense at ~$1.25 vs $40-60 for the BX-24 or ZX-24
although there are no free Basic language compilers for PICs. I will try to
remember to create a PIC program for this and send you a vector board
circuit when I get to the wireless thermometers.

I've been struggling with roZetta, partly due to being hampered by health
(and age) issues, partly due to other outside events (my building was for
sale and there were prospective buyers traipsing through frequently), and
partly because some of the features that make the ZX-24 attractive needed a
lot of code to make use of them. The new owner of the building was here
yesterday so that's no longer an issue. A recent discussion on the ZBasic
forums has resolved some of the programming issues and I now hope to have it
ready in a couple of weeks.

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
>news:44312352.856750640@xxxxxxxxxxxxxxxx
>> You could do this inexpensively by using an 8-pin PIC with ADC (e.g.
>> PIC12F675) and the RF receiver listed in the BX24-AHT Bill Of Materials
>(on
>> Jeff Volp's site).
>
>Stop reading my mind!!! :-) I just sat down to write and ask if the BX24-AHT
>could be modified to show a "good X-10 signal received" via an LED output.
>
>> Pin 2 of the receiver gives a linear output which you can
>> measure with one of the ADC inputs. Measure the amplitude
>> difference between a pulse and space. You could use an LED
>> indicator and vary the brightness as a function of signal
>> strength using PWM.
>
>By ADC I assume you mean Analog to Digital converter.  I'm afraid although I
>can follow the concepts, translating that into a circuit diagram is beyond
>my skills.  It may be that the RF sensing pen I wrote about could be up to
>the task of finding a stuck ON unit if I'm able to mount it in a can and
>operate it directionally.  I really surprised that there isn't a low cost
>COTS solution to this problem.  I am going to mount the TM751/ESM-1 combo
>inside an old 12" parabolic lamp reflector.  That should give me some
>feeling for whether a battery operated unit would work well.
>
>> You can probably get by with an inefficient monopole wire
>> antenna and can power it with batteries. Just remove the
>> batteries when it's not in use as the constant RF noise will
>> drain them. Cost is about $10-15 exclusive of shipping and
>> paying someone to do the soldering.
>
>I don't think that I could design something even that simple, Dave.  :-(
>If the reflector works, I'll be happy enough.
>
>Let me know if you'll still be able to incorporate the RatShack wireless
>thermometers in your new device.  I'll ship them out whenever you need them.