Useful for finding the 12/12 or 18/6 pattern spikes of a weed grow house also.. `
Still easier to do thermal camera search, you don't have to find which address it actually is.
Monitoring Home Power Consumption for less than $25
71–80 of 137 posts
Re: Monitoring Home Power Consumption for less than $25
#72rtlamr is awesome. I use it to monitor my gas meter (which is going crazy lately with the low temps here in Ohio).
I had started a project [1] to read my water and electric meters, but just about the time I started figuring out the protocol, they upgraded the firmware and turned on encryption. Luckily the encryption seems to only affect the power meter, as I am still able to read the water meter (though I’m not sure how long that will last)
Re: Monitoring Home Power Consumption for less than $25
#73Pedantic engineering correction. The units are "watt-hours" or "watt hours", not watt/hours.
Re: Monitoring Home Power Consumption for less than $25
#74Nice method, but for future record you don't really need to mess with mains to hook up Sense or OpenEnergyMonitor, they use inductive current clamps which work by detecting the field around the a single terminal of your incoming mains. Pretty much as safe as it gets with this stuff.
Sense actually has you install a 240v breaker in addition to the clamps.
https://sense.com/help/installguide.pdf https://youtu.be/qh9m2xuDrW4
Re: Monitoring Home Power Consumption for less than $25
#75It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.
Why 64 bit? The minimum key strength supported by AES is 128 bits, so 64 bits seems very low.
Probably to keep hardware costs low.
Re: Monitoring Home Power Consumption for less than $25
#76Earlier quoted context omitted.
The clamp only systems lack accuracy due to not measuring supply voltage. Commercial/open source energy meters based on chips like the ADE7953[0] have a resistive voltage divider to attenuate the supply voltage to suitable level for the chip but preserving the envelope for sampling. The problem is there is no galvanic isolation, so interfacing is harder. [0] http://www.analog.com/en/products/analog-to-digital-convert…
There are transformer isolated energy monitors like MAX78615. Much safer to work with.
Resistors are cheaper. Much better for the bottom line.
Re: Monitoring Home Power Consumption for less than $25
#77It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.
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 consumption. Of four recources commonly metered in Russia - electricity, water, gas and heat - three should use autonomous power. We also making an autonomous plug-in modules for popular "dumb" electricity meters - to simplify installation. They broadcast once a day too so the battery could last for 6 years.
Re: Monitoring Home Power Consumption for less than $25
#78It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.
Why 64 bit? The minimum key strength supported by AES is 128 bits, so 64 bits seems very low.
To reduce power consumption by using simple hardware. See my answer to @mrb above.
Re: Monitoring Home Power Consumption for less than $25
#79Earlier 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…
Still, the comment above still stands. Not sure about the key bruteforcing estimates, surely a couple of days of readings would be enough.
Are the keys stored on the devices? Is it a shared key?
Re: Monitoring Home Power Consumption for less than $25
#80> Some research told me that the power company accomplishes this via a simple radio broadcast on the 900Mhz spectrum. Interesting. Around here (mainland Europe) they're currently installing "smart" meters which do this using CPL rather than radio. > And with one simple command, I was reading the power (and probably water) meters for my entire neighborhood That is a bit troubling from a physical security perspective,…
Interestingly, in the UK utilities are using GSM SIM cards in Smart Meters, and a mixture of SMS and data to monitor/send electricity usage.
Those smart meters should be outrageously expensive both in production and running. Are utilities government-sponsored in UK?