I'm not familiar with the RTL-SDR. Why would one use that to monitor temperature/humidity over something like an arduino + sensors?
Monitoring Home Power Consumption for less than $25
111–120 of 137 posts
Re: Monitoring Home Power Consumption for less than $25
#112Reading this piqued my interest as this is something I’ve wanted to do ever since my local electric company started to roll out smart meters.
I took a look at my electric company’s web site to see what kind of meters they use and it turns out that they have already seen this need. They will enable the ZigBee module in the meters and set it up to talk to a home energy monitoring device (which you have to buy separately)[0]. The fact that this is officially sanctioned is pretty cool!
Once of the devices, the Rainforest Eagle, even has API documentation[1] so that you can build this type of thing, but with real-time data. The best part, from my point of view, is that they expose an API via their Cloud service AND have a local API on the device itself. It’s possible, though I have no way to know this without buying one, that you may even be able to use it completely independent of their Cloud service. So far the only limitation I’ve found while reading the docs is that you seem to need the Cloud service to configure the Push API, but I didn’t notice that limitation with the Pull API.
[0] https://www.epcor.com/learn/meters/advanced-meters/Pages/hom...
Re: Monitoring Home Power Consumption for less than $25
#113* OWL power monitor with inductive clamp and separate LCD display (in the reduced bin at the local DIY barn), transmits data on 433MHz - £12 * Arduino Mega+ESP8266 combo board - £8 * Rflink Rx/TX board - order a kit or build your own ( http://www.rflink.nl/blog2/wiring ) 433 or 868MHz operation, can also work with some devices at 2.4GHz - About £15 * Rflink software ( http://www.rflink.nl/blog2/ ) + Serial link softw…
True, though this isn't for everyone. To quote the article why the author didn't in this case...
...I HATE electricity. Too many years of geeky endeavors have resulted in far too many shocks, and mains electricity scares the hell out of me.
Re: Monitoring Home Power Consumption for less than $25
#114Earlier quoted context omitted.
There are transformer isolated energy monitors like MAX78615. Much safer to work with.
Resistors are cheaper. Much better for the bottom line.
MAX78700 uses a pulse transformer for isolation from the MAX78615, and is powered by the '78615 via that same transformer. It uses resistors for voltage and current sensing.
Re: Monitoring Home Power Consumption for less than $25
#115I do something similar at home. However, the meter in my house has a LED that blinks per Wh used, so all I did is put something light sensitive on top of it, wire it to a tiny board of your choice (GPIO on a Raspberry Pi in this case) and then export the data from there. I run a tiny Prometheus exporter on that same Pi which gets scraped and everything neatly shows up in Grafana. For other devices I use Z-wave powere…
This gets challenging when you have solar export and a bidirectional meter. The light blinks for every _absolute_ kWh. That is, you don’t know if that was imported or exported electricity, so you need additional information. One approach I’ve seen is to use current clamps just to work out the difference between what’s coming out of the solar inverter, and what’s going into the house. If a > b then the blinks are export, and vice versa.
Re: Monitoring Home Power Consumption for less than $25
#116"I'm not going to lie. It felt weird polling the meter readings for the entire neighborhood." Yikes, and I though we had it bad here in the Netherlands where you explicitly needed to opt-out of your power supplier being able to read your meter. At least here it is ordered that if these newer 'smart meters' are to be installed they always need to include a 'P1 port' which allows the home owner to simply read out the m…
Wish that an accessible real-time port was required here in Australia. Best I can do is download the 30minute interval data from my electricity retailer after the meter sends them overnight (or use other hacks like reading the blinks)
Re: Monitoring Home Power Consumption for less than $25
#117Reading this piqued my interest as this is something I’ve wanted to do ever since my local electric company started to roll out smart meters. I took a look at my electric company’s web site to see what kind of meters they use and it turns out that they have already seen this need. They will enable the ZigBee module in the meters and set it up to talk to a home energy monitoring device (which you have to buy separatel…
I built a purely local version using the Raven USB Zigbee modem, flask and D3.js. Crude, uses SQLite but might be of interest. The XML decoding is only hard part really.
Re: Monitoring Home Power Consumption for less than $25
#118Earlier quoted context omitted.
That's great, but using a 64-bit key in 2017 isn't "taking security seriously". Especially if you are designing meters that will have a lifespan of 10+ years, therefore must be secure until 2027 and beyond.
Our most talkative meters are currently broadcasting 4 packets of data per hour. Water meters with autonomous power are limited to one or two (for central hot water supply) packets per day. With all the randomness added collecting data for successful key bruteforcing will take months or even years. On the other hand, using 64 bits allows us to use 16- or even 8-bit microcontrollers, which is beneficial to power consu…
I can't speak to the specifics of your project, but 128-bit symmetric crypto on 8-bit microcontrollers is perfectly possible, at a low power budget and with relatively small code and RAM usage.
Re: Monitoring Home Power Consumption for less than $25
#119I have five or six different RTL-SDR dongles that are looking for something to do, so I am interested in this project. But it seems that I have to install a GO ecosystem on my computer in order to compile and run the program. That is a step too far for me in order to just kick the tires.
Does anyone know of a prebuilt windows binary for this? (I have always heard that is one of the strengths of GO -- it produces a simple standalone binary)
[edit: I'm really referring to rtlamr, not the project described in the post. first I would want to get rtlamr running before attempting to get the datebase / presentation program running]
Re: Monitoring Home Power Consumption for less than $25
#120How does the power company actually get the information transmitted by the meter?
One of the articles the author links to says that it is collected by the power company sending someone with an appropriate receiver to drive around collecting the data.
However, my power company website lets you look up your usage on their website, and that is updated daily which makes me seriously doubt that there are any manual steps in its collection. In particular, it gets read on those occasions every few years when we get enough snow to close down traffic on side streets like mine.
My meter is at least 11 years, and appears quite old fashioned--it's got the spinning disc to show instantaneous usage and analog dials to display the cumulative usage.
I'm not actually sure that my meter has remote read capability. I read somewhere that some power companies add remote reading to older installations by putting something on the pole where the lines to a particular house branch off.
There are some mysterious signals in the 900 MHz neighborhood that show up on my SDR. I've seen them at 929.616, 929.664, 929.940, 931.066, 931.216, 931.865, and 931.942 MHz, and have not been able to figure out what they are from. Mostly, they consist of periodical short (about 1 second) bursts of something digital followed a few seconds later by a longer burst (several seconds), then silence for maybe a minute, and then repeat.
Some seemed to be in pairs, where one would send a short burst, then another would send a long burst. I suspected that this may have been my "Weather Channel" weather meter, which has an outdoor sensor and an indoor display, and operates in the 900 MHz area. I suspected the short burst was the indoor unit asking the sensor for a report, and the sensor responding. I ruled that out, though, by taking the batteries out of the indoor unit and seeing no change in the signal pair.
It's been a while since I looked at these, and so I took another look--and now I don't see that apparent pair. I'm not thinking that that one wasn't two things talking to each other, but two separate things that just happened to have their reports lined up so that it looked like they were talking to each other.
I had guessed that they might be power meters, but I have not been able to find anything that looks like it could be the receiver for them. I don't see anything on the poles around here other than the usual transformers, and we don't have any evident equipment pedestals. The signals don't seem very strong, so I've been assuming that whatever they are talking to cannot be far away. That made power meters seem less likely.