real time power meter


My family is out of town so I have (finally) had a chance to try and track down some nasty passive power loads. With my family around I get too many screams of pain when I switch breakers off during the day!

I was spurred into action today as I noticed (via Flusko) that my house was using 550W (13.2 kWh/day) with no one home. About 350W of that is the average load of our fridge + deep freezer. About 140W are some passive loads that I have yet to track down, and about 60W my laptop and basic "nerd" IT that is running most of the time.

To keep Flusko running I powered my DSL modem and Wifi router (plus the Flukso) from a 12V battery via an inverter.

The only problem I found was that as I switched off loads the update time of Flusko graph was very slow, for example 5-10 minutes. Is there any way to speed this up?

What would be ideal was a some sort of real time power meter application I can run here, rather that waiting for the web graphs to update.



yschaeff's picture

This is an item on my wish list as well. I intent to collect higher resolution data by reprogramming the sensor board and writing the data to an external device with more resources. Then we could make all kind of fancy sugercoated real time graphs in OpenGL.

Ofcourse I'd like to aggregate that data and send it at regular intervals to When I have time (within weeks / months?) I'll try to mimic the fluksometers XMLRPC call. I'd like to do this in python as Lua is not my cup of tea.

icarus75's picture

Hi David,

Here are some ways of achieving a (near) real-time power meter. We could:
1/ Adapt the daemon on the Fluksometer to calculate a power reading from the incoming pulses or ADC values. We'd probably have to implement some sort of low-pass filtering so that the output is not too jittery. We would then have to make this power reading available. I can come up with two options here:
a/ Broadcast on the local domain ( and a fixed UDP port
b/ Overwrite a local /tmp/power file (in RAM) each time a new value is calculated. This value could be read out and presented on the Fluksometer's local webpage.

Option 1 is a bit of a hack since a Fluksometer doesn't know which type of variable(s) it is measuring: kWh's, liters, m3, ... The mapping of sensor id to unit resides on the server side. And yes we're reading only kWh's for now. But the platform was made so that all kinds of variables could be measured and reported to the Flukso server. The internal digital ports are pre-provisioned from v1.1 on. So if you'd hook up a sensor to them, the Fluksometer would start reporting them to the server right away. A web interface would allow you to map the sensor id to a type/unit.

2/ Implement a boost button on the Flukso website. Push the button and the reporting interval would decrease from the default 5min to e.g. 1min. After a fixed time, say 30min, the Fluksometer would return to reporting values with the default interval. This would entail a modification of the web service call. A remote update feature is present on the Fluksometer, so we could update them in the field if necessary. After some thorough testing of course. :-)

Would option 2 meet your needs?
If you can think of other alternatives, shoot!


drowe67's picture

Hi Bart,

Either of those options would be great.

OK, so the default update is 5 minutes, I didn't realise that. If no power is being used, does that mean no pulses are sent to the server? I was wondering how long it takes to update when no power is being consumed. When I was doing my low power tests it looked like updates slowed under very low power consumption.



>About 350W of that is the average load of our fridge + deep freezer.


*ouch!* :)

my fridge ( has a peak load of <50, and that is VA, not Watt. Average load should be below 20VA. Highly recommended device, btw. The deep-freezer box is not too big, but it`s quite ok for us.....

gonium's picture

As for the real time power measurements, I am currently running a visualization on a Chumby to do this. Here's a small preview:


I will release the full documentation and software soon. In the meantime, you can check out the mySmartGrid developer wiki:

ChumbySoftware page

Stay tuned!

skynetbbs's picture

nice movie.... perhaps best is to put it on youtube?