Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by stuart on Wed, 08/07/2015 - 11:58

If you have a USB bluetooth adapter, you can wirelessly capture data from an SMA solar inverter (I've got a 3000HF model)

The code uses MQTT to push data into emonCMS

https://github.com/stuartpittaway/SMASolarMQTT

Its useful because it captures both AC and DC power readings directly from the inverter - as well as overall yield in kWh.

In emonCMS, the code mimics the appearance of 4 separate notes numbered 50-53

Its still early days for the code, but it's been running for a few days non-stop now, and captures values such as...

ACOutputPhase1
ACOutputPhase2
ACOutputPhase3
ACLineVoltagePhase1
ACLineVoltagePhase2
ACLineVoltagePhase3
ACLineCurrentPhase1
ACLineCurrentPhase2
ACLineCurrentPhase3
ACGridFrequency
TotalYield
DayYield
OperatingTime
FeedInTime
DCVoltage
DCCurrent
DCPower

Please let me know if you find this useful.

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by bruce_miranda on Thu, 09/07/2015 - 07:29.

I don't have a Bluetooth adapter, my SMA was one of the newer ones that came with the inbuilt SunnyPortal Ethernet connection. So it sends information to SunnyPortal.
I have been trying to see if I can intercept the messages for my own logging to cms. So am interested in what you are doing.

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by stuart on Thu, 09/07/2015 - 19:44.

Not seen one of the newer inverters, have you tried monitoring the network using wireshark or something similar?

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by gloorung on Tue, 11/08/2015 - 08:15.

Sounds very interesting ! I've tried your code with a SMA 4000HF. It connects and reads out the values from the invertor correctly (based on the print messages), but I'm having some problems getting the values into emoncms. I can't see any mqtt packets in the emonhub log (debug mode). I don't have the emonPI, but I'm running emoncms v8.5 with the emonpi version of emonhub on an odroid, so mqtt should be enabled. Anything you can think of that I might be doing wrong ?

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by Ian Eagland on Tue, 11/08/2015 - 14:27.

You might find this thread helpful

http://openenergymonitor.org/emon/node/10746

Regards

Ian

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by derek_j on Thu, 24/12/2015 - 15:28.

New openenergy monitor user here. Thanks for the code it was just what I needed for my new SMA 3600 inverter. It has been working for the last day. All I had to do was define a systemd unit to start it.

Observations so far :-

* It was not necessary to start the bluetooth service. It runs without it.

* My bluetooth dongle is very temperamental. It is not recognised from boot, I have to unplug and reinsert it. Also it often disappears while in use and has to be plugged back in again. It would be handy if there was a way to 'virtually' unplug it from the command line. Maybe I should just buy a new dongle.

* Node 51 DC_Watts is commented out in the code, but if I uncomment it it works OK

* For reasons I do not understand emoncms lists 10 items in Node51 each item is named with one letter of the words 'SolarDCWatts'

* The code does not retrieve separate DC information for the two strings of solar panels.

Re: Talking to an SMA solar inverter from emonPI and emonCMS - MQTT

Submitted by derek_j on Fri, 01/01/2016 - 14:41.

I worked out how to get information on the DC strings. The data was alteady being collected, but was just not being published.

In SMASolarMQTT.py from line 171

                    print("dc v/a")
                    # These values only update every 5 mins by the inverter.
                    #0x451f String1 DC Voltage V
                    #0x4521 String1 DC Voltage V
            #String1 DC Current A
            #String2 DC Current A
                    L2 = SMASolarMQTT_library.spotvalues_dc(btSocket, packet_send_counter, mylocalBTAddress,
                                                            InverterCodeArray,
                                                            AddressFFFFFFFF)
                    packet_send_counter += 1
                    payload = "{0},{1},{2},{3}".format(L2[1][1], L2[2][1], L2[3][1], L2[4][1])
                    client.publish(topic_spotvalues_dc, payload=payload, qos=0, retain=False)
                    time.sleep(1)

and in emonhub.conf

[[53]]
    nodename = SMASolarMQTT_DC
    firmware = not_applicable
    hardware = not_applicable
    [[[rx]]]
       names = String1_DCVoltage, String2_DCVoltage, String1_DCCurrent, String2_DCCurrent
       datacode = h
       scales = 1,1,1,1
       units =V,V,A,A

This works in my SMA3600. I do not know if it would be the same in other inverters

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