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Topic: Adapting eHZ IR receiver schematics for Arduino? (Read 2023 times) previous topic - next topic



I'd like to use an Arduino board to capture data from smart meters - devices like these:

They have an IR transmitter that sends a SML package about every 2 seconds. From what I've read so far, the transmission uses standard serial protocols (9600 baud, 8N1 or 7E1), so I should be able to use the onboard UART, right?
I've found some schematics for an IR interface at http://wiki.volkszaehler.org/hardware/controllers/ir-schreib-lesekopf#stromlaufplan (I need only the first part, the second part is the IR transmitter). Some of the components that are used there are not that easy to get for me, and I wonder whether I really need all this or if there's a simpler way to get this done. Does anyone have expericene in this area?



I thought smart meters used a wireless protocol, not IR. Have you got a spec of what it sends?



Pete: I'm unsure about the difference between IR and wireless protocol - I'm more the software guy. With "IR", I only meant the frequency of the light - infrared instead of visible light. Some general notes can be found at http://en.wikipedia.org/wiki/IEC_62056. As far as I understand the matter so far, this is just a standard asynchronous serial transmission like RS-232, but using infrared light instead of a direct electrical connection.


I'm unsure about the difference between IR and wireless protocol - I'm more the software guy

You really are stretching my credibility to the breaking point. What kind of software guy doesn't know the difference between IR and wireless/wifi/etc.?

But, *if* the meter follows the specification you linked to, that communication protocol requires that the meter reader press a reading device against the faceplate and the reader device must then identify itself before data is transmitted. So, in that case unless you know how to transmit the identifying code you aren't going to get any response from the meter.



Pete: This might not be a problem of credibility, but of technical jargon. Maybe we're thinking along the same lines, but I'm not able to provide the information you need because I don't understand the contradiction in "smart meters used a wireless protocol, not IR".

As for the identification, that's only necessary to change the configuration of the meter. Left to itself, the meter will send a SML message every two seconds, whether there's someone there to listen or not. One application is described here: http://kuehnast.com/s9y/archives/460-Stromzaehler-auslesen.html (german, sorry). I want to do something similar - intercept the contents of the message and store it for later processing.


If we're having language difficulties why don't you post this in the German language forum. I'm sure there are people there who can help you without tripping over the language.



Its not a language problem.

El_supremo is in the wrong here.

El Supremo thinks that Wireless has only 1 meaning WIFI. And true  North American meters use that form of communication.

And IR is a not wired form of communication so it to is WIreless.

If someone was not so  caught up in Trolling  they might have helped.

What you are looking for is here.



Gotta agree with that, you can see what appears to be the ir transmittoer port where it says "IR"


If someone was not so  caught up in Trolling

That's very interesting coming from someone who posted this in their very first message just ten minutes after they registered! At least you picked a descriptive login name for yourself.

you can see what appears to be the ir transmittoer port where it says "IR"

You get the prize for stating the bleeding obvious.

If either of you geniuses had bothered to read, and tried to understand, http://en.wikipedia.org/wiki/IEC_62056 you would see that the protocol described there is not one you can simply record and play back like a TV remote control. It involves handshaking which is a lot more difficult to decode.
If the meter does actually send an "SML Package" every 2 seconds it isn't defined there. And I don't read German but perhaps one of you can figure this out http://kuehnast.com/s9y/archives/460-Stromzaehler-auslesen.html and contribute something useful.



It's interesting to see where this discussiorant went, considering the original question (I was asking for some help with the circuit design, not the software, after all). In the meantime, I was able to get things working, with considerable help from the person who designed the circuit I originally referred to. The schematics and some documentation are available at https://sourceforge.net/p/ehzy/wiki/Hardware/.

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