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Re: ESP with MODBUS protocol

PostPosted: Thu Jul 16, 2015 7:22 am
by Aledav
Hello,
I have experience with the SDM120c. I ordered another from China with Aliexpress:
http://www.aliexpress.com/item/SDM120C- ... 29725.html
Also sdm120 can 'work to 240 Volt
    Nominal Voltage(Un): 230V AC
    Operational Voltage : 176~276V AC

While DRS-205C:
    output Voltage:120V/ 230V
240 ?
There is also the SDM220Modbus but I have no experience.
I used the SDM120c with Raspberry with a USB / RS485 like this:
http://www.ebay.com/itm/New-USB-to-RS48 ... 58bb354d7f

I installed Nodejs and interrogate the SDM120c from Raspberry with the API:

https://github.com/gianfrdp/SDM120C

I write a little html page which send (socket.io) readings at intervals of 2 seconds.

I'm recording all the data every two minutes on a Firebase DB and writing a nodejs app to analyze them!
The works is in progress!!

I'd like to read the second sdm120c via wifi to connect for example to an inverter grid tie that reads energy production, or
to another user far from the raspy I want to monitor.
You could use to monitor the consumption of several apartments in a residence, etc.
Too bad I do not know LUA, actually I have not updated the firmware esp8266 for testing (do not have much time available).
I hope to do some testing during the holidays, but where I live, the sea is very nice !!!! :D
I'm happy someone else and interested in making this small project and share the software free to all!
Do you think that the electrical schematic that I drew, it can work?

Re: ESP with MODBUS protocol

PostPosted: Thu Jul 16, 2015 12:54 pm
by Aledav
Quick Details from ali:

Place of Origin: China (Mainland)
Brand Name: Eastron
Model Number: SDM120C
Display Type: LCD diplay
Phase: Single Phase
Measuring Energy Range: working voltage 220/230/110/127
Accuracy Class: better than Class 1
Operating Temperature: -25~+55
Dimensions: 119x62x17.5
current: 5(32)A, 5(40)A, 5(45)A

http://www.alibaba.com/product-detail/S ... 90711.html

Re: ESP with MODBUS protocol

PostPosted: Fri Jul 31, 2015 2:48 am
by sjfaustino
frank_dunn1 wrote:I have tried to get modbus Tcp to work on a olimex board with esp8266 , it needs a lot extras to be added in but basic function 3 and 6 for 1 register with crc16 works . I can share the code if you want it.

I'm also interested in the working code if you woudn't mind sharing it.

Re: ESP with MODBUS protocol

PostPosted: Fri Jul 31, 2015 8:09 pm
by tytower
Well the first bit is somewhere public to put the data so
http://ubidots.com/features-create-custom-insights.html
seems to have suitable displays but it would need a longer reading space say 30 seconds .

Then we just need the IDE code to extract the data from the sensor so see here
download/file.php?id=1134

I still hav'nt got my power sensor though so I can't put it together yet.