The following code is running in a System with 2 SMA Tripower, 1 SMA Storage Boy 3.6 and a SMA Home Manager 2.0. In this system I added a Victron Multi Plus 2 GX and lifepo4 batteries. ESS is installed and grid feed in is disabled. This is Storage Boys job. The Multiplus has to run my server 24/7 and use only the large lifepo batteries. They will be recharged if there is overproduction or the SoC reachs 0%.
This small program emulates the ET340 Energy Meter in a Victron ESS System. It reads values from an existing SMA Home Manager 2.0, and publishes the result on dbus as if it were the ET340 meter.
Use this at your own risk, I have no association with Victron or SMA and am providing this for anyone who already has these components and wants to play around with this.
I use this privately, and it works in Europe, your results may vary.
In case you want to compile the tool by yourself or need some changes later on, you need to install the go Software. Follow the guides on their page according your operation system. Otherwise you can use my precompiled .arm file. It is the one without extention.
Setup your GX device and enable SSH. In my case I enabled the ESS too.
1: Test First ensure that this will work: Try out the ready compiled .arm https://github.com/Schnema1/shm-et340/blob/master/sma_home_manager_printer which will run on your Victron GX device and try to connect to the SMA meter. The above test program does not publish its result on dbus for use by victron, only prints out the result for your verification. It should be relatively safe to test with.
If the sma_home_manager_printer works and shows consistent/reliable result, then you can
install the shm.et340 in the same way.
While this is running, you should see correct values for a grid meter in your Venus UI:
On the console of your GX device, you should see regular updates, around once per second:
root@victronvenusgx:~# ./shm-et340
INFO[0000] Successfully connected to dbus and registered as a meter... Commencing reading of the SMA meter
INFO[0000] Meter update received: 6677.15 kWh bought and 3200.45 kWh sold, 681.3 W currently flowing
INFO[0001] Meter update received: 6677.15 kWh bought and 3200.45 kWh sold, 694.1 W currently flowing
INFO[0002] Meter update received: 6677.15 kWh bought and 3200.45 kWh sold, 686.3 W currently flowing
If this does not work, try to export LOG_LEVEL="debug" first, which should print out significantly more
information on what's happening.
For more details, see the thread on the Victron Energy community forums here:
https://community.victronenergy.com/questions/49293/alternative-to-et340-mqtt-sma-home-manager.html
The script only works as long as you computer is connected through SSH. This is not what I wanted and probably not what you want. We need to create an config file in order to get the shm-et340 run automaticly at system boot.
create a file in /data/ called rc.local -> /data/rc.local make it executable chmod +x and add the following two lines of code. Just as mitchese did. Remember to change the file name if your one is not called shm-et340
!#/bin/bash sleep 15 setsid /data/home/root/shm-et340 > /dev/null 2>/dev/null &
After you have saved it, you type reboot and take a look at automatic running energymeter.