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Blueline / Black & Decker Power Monitor RF Packets
Update 2014-10-02: I’ve forked Bryan’s Arduino code and added some instructions: scruss/Powermon433 (though use Bryan’s, srsly)
Update 2014-08-19: Bryan Mayland has decoded the data on Arduino! More details here: CapnBry/Powermon433
Given that I first started thinking about reverse-engineering the Blueline Powercost Monitor‘s data stream in September 2010, I hardly win any awards for rapid development. Here’s what I know so far about the device and its transmissions:
- The Blueline unit and the (now discontinued)Â Black & Decker Power Monitor (EM100B) appear to be functionally identical. Both transmit data using simple ASK/OOK at 433.92 MHz in the ISM band.
- It is, however, completely different from the Norgo NGE101 meter, dammit.
- The display unit is made by Hideki Electronic Limited, who make many small weather stations and wireless displays. [Pictures of the display circuit boards]
- The transmitter unit was designed by Intectus in Ottawa for Blueline. It uses a TI MSP430 µcontroller. [Transmitter board picture]
- The transmitter can be triggered by simulating a power meter if you flash a 940 nm IR Emitter LED for 50 ms into its sensor. 1× 50 ms flash represents 1 Wh of power consumed. A pulse frequency of 1 Hz represents 3.6 kW consumption.
- The transmitter sends a bundle of three (seemingly) identical packets every 31.8 seconds. These appear to contain consumption data, as the display updates approximately every 32 seconds.
- A series of contiguous packets, recorded as audio using a simple circuit described by the Protocol Analyzer project: audio201311182215-silenced (FLAC; please note that interstitial silences have been blanked to reduce file size).
- Temperature packets may be sent separately from power, as the display updates temperature much more slowly than power use.
- Power packets only appear to contain use data (along with a transmitter ID). If the sensor receives an absolutely constant input, the packets transmitted 32 s apart can be identical.
- The packets appear to be Manchester-encoded.
Some rough notes on mark/space timing (all times in µs):
Mark : Mean   529.4 Min   499.0 Max   590.0 StdDev:  15.03 Space: Mean   694.5 Min   385.0 Max  1474.0 StdDev: 281.57
Mark/space times, by frequency (all times in µs):
MARK ==== µS Rank    Value  Count -------- ------- -----     1       522 498     2       544 206     3       567  32     4       499  32     5       590   8 SPACE ===== µS Rank    Value  Count -------- ------- -----     1       476 279     2       975 223     3       454  99     4       952  65     5       431  26     6      1474  22     7       408  21     8       499  17     9       998  12    10    199000   8    11       385   2    12      1451   2More later, including raw packet data.
Thanks to Randy Simons and Bryan Mayland for the recent help. Thanks too to Brett “Wiring†Hagman for asking just why I was trying to do this …
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We won’t, we won’t Roku …
I’m pretty sure the 9V DC power supply for one of my Roku Soundbridges shouldn’t be doing that ↑↑ . This is the second unit I’ve had to replace, my other Soundbridge blowing its 5 V supply a couple of years back. This one cycles from 9.4 to 4.4 V about 5 times a second. Not very DC, but kind of lethargic for AC.
It’s hard to tell, but one of the caps inside the rather complex little Unifive wall wart may have blown. I’ve scrapped the PSU and replaced it with a beefier one. It seems that power supplies are a problem (see: 1, 2, 3, 4) on these machines, so I wonder when/if I will need to replace this one.
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Serious nostalgia…
Oh man — emulating an Atari ST. It’s 1987, and I’m back in that computer lab on the first floor of the James Weir Building …
(Jeremy Ruston went on to write TiddlyWiki, amongst other things.)
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Protext lives!
Oh man, Protext! For years, it was all I used: every magazine article, every essay at university (all two of them), my undergraduate dissertation (now mercifully lost to time: The Parametric Design of a Medium Specific Speed Pump Impeller, complete with spline-drawing code in HiSoft BASIC for the Amiga, is unlikely to be of value to anyone these days), letters —you name it, I used Protext for it.
I first had it on 16kB EPROM for the Amstrad CPC464; instant access with |P. I then ran it on the Amiga, snagging a cheap copy direct from the authors at a trade show. I think I had it for the PC, but I don’t really remember my DOS days too well.
The freeware version runs quite nicely under dosemu. You can even get it to print directly to PDF:
- In your Linux printer admin, set up a CUPS PDF printer. Anything sent to it will appear as a PDF file in the folder ~/PDF.
- Add the following lines to your ~/.dosemurc:
$_lpt1 = “lpr -l -P PDF”
$_printer_timeout = (20) - In Protext, configure your printer to be a PostScript printer on LPT1:
The results come out not bad at all:
Protext’s file import and export is a bit dated. You can use the CONVERT utility to create RTF, but it assumes Code page 437, so your accents won’t come out right. Adding \ansicpg437 to the end of the first line should make it read okay.
(engraving of Michel de Montaigne in mad puffy sleeves: public domain from Wikimedia Commons: File:Michel de Montaigne 1.jpg – Wikimedia Commons)
