elnasmartmeter 1.1.1

A simple library for the E.ON Elna API written in Python 3.

Elna SmartMeter Library

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Introduction

A simple library for the E.ON Elna API written in Python 3. Elna is a smart power meter that is plugged in to the HAN (Home Area Network) port of the electricity meter using an RJ12 connector.

This library is using the built-in API in the Elna device to gather information, about your power consumption and/or production, directly from the device itself.

Elna is based on hardware from Net2Grid so it's probably also compatible with more devices from the Net2Grid family. Any feedback is welcome.

Demo

Here is a small command-line demo application showing the information that can be obtained by the library.

Check out the source code to the demo here: smartmeter-demo.py.

Installation

Setup the virtual environment:

virtualenv venv
source venv/bin/activate

Install the latest version with pip:

pip install elnasmartmeter

Basics

Setup

In order to use the library you need to know the IP address of the Elna device. You can find it in the DHCP server of your router (or wherever you are running your DHCP server). The MAC address of Elna is printed on the back of the device.

from elna import smartmeter

# Connect the library to the Elna device
meter = smartmeter.Connect('192.168.0.10')

# Get general information
info = meter.get_info()

# Get power readings
electricity = meter.get_electricity()

It's as simple as that to fetch the power consuption/production of your household. In a moment we will be looking at how to access the information via the info and electricity objects.

Exceptions

All of the methods callable from the library will throw exceptions on failure. A full list of exceptions can be found here.

from elna import smartmeter
from elna.exceptions import *
...
try:
    info = meter.get_info()
except NewConnectionError as e:
    print(e)

Printing Objects and Properties

The objects representing various entities in the library can be output with the print() method for easy inspection of its properties.

As an example, you can output the properties of an Information object by passing it to the print() method:

print(info)
# Output: <class 'elna.classes.Information'>: {'id': '01ab:0200:00cd:03ef', 'manufacturer': 'NET2GRID', 'model': 'SBWF4602', 'firmware': '1.7.14', 'hardware': 1, 'batch': 'HMX-P0D-123456'}

Also, the properties are easily accessed from the object:

print(f"Model    : {info.model}")
print(f"Firmware : {info.firmware}")

The same goes for all object classes in the library: Information, Electricity, Power and WLANInformation.

Access the Data

There are two pieces of data that can be fetched with this library: general device Information and Power statistics.

Device Information

To get the general device information we just call the get_info() method.

info = meter.get_info()

Access the values via the class properties:

info.id                         # Returns the device ID        : '01ab:0200:00cd:03ef'  (for example).
info.manufacturer               # Returns the manufacturer     : 'NET2GRID'
info.model                      # Returns the model            : 'SBWF4602'
info.firmware                   # Returns the firmware version : '1.7.14'
info.hardware                   # Returns the hardware version : 1
info.batch                      # Returns the batch number     : 'HMX-P0D-123456'

Power Readings

To get the power readings we call the get_electricity() method. These readings are a bit more complex since the information gathered from the Elna device is divided in to sub-classes, but it's not that complicated:

electricity = meter.get_electricity()

Now

Get the current power consumption:

electricity.now.key             # Returns the string  : 'now'
electricity.now.value           # Returns the power   : 453  (for example).
electricity.now.unit            # Returns the unit    : 'W'  (as in Watt)
electricity.now.timestamp       # Returns a timestamp : '2022-12-24 13:37:00'

Minimum

Get the minimum power consumption in the period:

electricity.minimum.key         # Returns the string  : 'minimum'
electricity.minimum.value       # Returns the power   : 202  (for example).
electricity.minimum.unit        # Returns the unit    : 'W'  (as in Watt)
electricity.minimum.timestamp   # Returns a timestamp : '2022-12-13 13:37:00'

Maximum

Get the maximum power consumption in the period:

electricity.maximum.key         # Returns the string  : 'maximum'
electricity.maximum.value       # Returns the power   : 14320  (for example).
electricity.maximum.unit        # Returns the unit    : 'W'  (as in Watt)
electricity.maximum.timestamp   # Returns a timestamp : '2022-12-31 13:37:00'

The time frame (period) of which the minimum and maximum values has been recorded is unknown (to me).

Imported

Get the imported power. This would be total power coming into the household:

electricity.imported.key         # Returns the string  : 'imported'
electricity.imported.value       # Returns the power   : 12345678  (for example).
electricity.imported.unit        # Returns the unit    : 'Wh'  (as in Watt hours)
electricity.imported.timestamp   # Returns a timestamp : '2022-12-31 13:37:00'

Exported

Get the exported power. This would be total power coming out of the household:

electricity.exported.key         # Returns the string  : 'exported'
electricity.exported.value       # Returns the power   : 87654321  (for example).
electricity.exported.unit        # Returns the unit    : 'Wh'  (as in Watt hours)
electricity.exported.timestamp   # Returns a timestamp : '2022-12-31 13:37:00'

Check out the smartmeter demo at the top to try it out.

WLAN Information

We can also get the WLAN information of the device by calling the get_wlan_info() method. The device can act as both a Wireless Client (Station) and an Access Point (AP) depending on if it has been connected to you WiFi network or not.

wlan = meter.get_wlan_info()

Access the WLAN information via the class properties of the object:

wlan.mode           # Returns the current WLAN mode
wlan.ap_ssid        # Returns the Access Point SSID
wlan.ap_key         # Returns the Access Point Password
wlan.client_ssid    # Returns the SSID of the AP Elna is connected to
wlan.join_status    # Returns the number of clients joined to the Elna AP
wlan.mac            # Returns the MAC address currently in use
wlan.ip             # Returns the IP address
wlan.subnet         # Returns the Subnet mask
wlan.gateway        # Returns the Default gateway
wlan.dns            # Returns the Primary DNS server
wlan.dnsalt         # Returns the Secondary DNS server
wlan.n2g_id         # Returns the Net2Grid ID number
wlan.sta_mac        # Returns the MAC address of the WLAN Station
wlan.ap_mac         # Returns the MAC address of the Access Point
wlan.eth_mac        # Returns the Ethernet MAC address (?)

Note: The descriptions following the WLAN properties above are estimated guesses.

Legal Disclaimer

The product names, trademarks and registered trademarks in this repository, are property of their respective owners, and are used by the author for identification purposes only. The use of these names, trademarks and brands, do not imply endorsement or affiliation.