iSKRA MT382

Hi all,

 

I'm a newbie so treat me gentle, please :-)

I've got three emonTx V3 which should monitors the power consumption of each group (once I finalize my built). To get a better total I'd like to read the "official" output of the Smart Meter (iSKRA MT382). The thing is though, I have no clue how to do this with the emonTx V3 I have right now...

The Smart Meter has an RJ11 connector which outputs the data (according to this article), but how do I read this data using a emonTx? Any help is welcome!

 

Kind regards,

Ingmar

IngmarVerheij's picture

Re: iSKRA MT382

Anyone? Please?

Robert Wall's picture

Re: iSKRA MT382

Clearly, nobody here has tried to do that. The article you quote indicates that the protocol is serial at 9600 baud, but the voltage levels are the same as the FTDI. Have you looked at Arduino tutorials for serial comms? It looks to me as if this http://arduino.cc/en/Tutorial/ArduinoSoftwareRS232 could be a starting point, and you'd also need to drive the "request" pin from an I/O line - I guess this instructs the meter to start sending the data - when you're ready to receive. And what he says about inverting - you'd do that in the sketch before you process the input.

dBC's picture

Re: iSKRA MT382

If you follow enough links/comments from your original pointer, you end up here:

https://github.com/willem4ever/Arduino-P1/blob/master/SmartMeter.ino

IngmarVerheij's picture

Re: iSKRA MT382

Wow! Thanks guys, really helpful! Software-wise I'm sure I'm able to get things sorted out.

Now - with the risk of asking a dumb question - how do I connect this to an emonTx v3? Can I somehow use CT4 for this or wire it up via the green block on the back (see attached photo)? Again, sorry for my newbie questions ;-)

 

 

 

 

Robert Wall's picture

Re: iSKRA MT382

CT4 isn't the place to connect anything other than a CT!
Have you looked at the schematic diagram for the V3? It's on GitHub and there's a link from the Wiki also - and that too is well worth reading. The schematic, Wiki plus the photo should tell you what's available. I haven't studied those links above in great detail so I can't say immediately what you need to do.

IngmarVerheij's picture

Re: iSKRA MT382

I'm starting to realise the emonTx V3 doesn't enable me to connect another serial input device. I'm looking for an Arduino Mega so I can read the input of water and warm water in the future, I'm sure I'll find some information about Arduino's and reading serial data on the interweb.

IngmarVerheij's picture

Re: iSKRA MT382

(talking to myself here, might as well use this thread for notes)

The emonTx has some digital input available (incl. 3.3V and 5V) which theoretically enables me to read the P1 from the MT382. All I have to do is add a 7404IC between the ATMEGA328 and the RJ11 and I'm good to go. But I'd rather not mess to much with my emonTx so I'd go with a separate device.

Since I'd like to read some more equipment (water and hot-water) I've got the TSL257 (optical pulse) and TSL261R (IR sensor) kits, so I need some more digital inputs for those. Since the P1 in the MT382 (which requires 5v) I can't  use a JeeNode (easy, cheap and comes with RFM12b) so I'll go for an Arduno Uno (still pretty cheap, small and cases avaiable).

 

Some resources I found useful:

and some other less related:

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