Skip to main content

The Internet of Meh

Yes, I know there are some very talented, hardworking people busy making "The Internet of Things" (IoT) a reality, and yes, there's even some govt money available just now. However there's still a huge hurdle to overcome before it will ever progress beyond a geek hobby.

Example 1: We have a solar PV system installed (Peak output 2500W) and happen to live in a Damn Sunny place. Great. So far it's chucked out ~2400kWh. Our daytime loads are the evaporative aircon (variable speed 1500w motor) and the pool pump (1600W, fixed speed, needs to run for ~8h day in summer). Together with 'normal' modern household appliances of Washing machine and dishwasher we *should* be able to balance our house load so we're roughly running "grid neutral" -- ie hardly importing or exporting during day. With the current tarrifs (feed in 8c/unit, consumption, 28c unit) it's just not cost effective to put a huge array up (ignoring the fact that we're restricted to 5kW max feed in anyway, and don't have unlimited roof space).

What I want is some smart magic load shedding intelligence - if we have sun, make sure pool pump has run for minimum amount of time. Look at weather forecast - no clouds predicted, take a chance on there being sun up till sunset (so we can predict insolation and expected output) and run for 4h morning, 4h afternoon. Spare capacity? sure - lets ramp up aircon and cool the house a little more comfortably. Oh wait - unexpected load? (dishwasher / WM on a daytime cycle) - back off the aircon, if its the dishwasher, we know that heating cycle will be over in X mins, so suspend the pump.

Sounds lovely right? sure it can be manually done watching the display on the PV inverter and the main electricity meter, but there's gotta be a better way. Well Tough. In Australia a standard domestic fusebox lurks outside, and has max 30 ways. Unless you're a licenced electrician, any poking in here is illegal, and so will cost you contractor rates. How many hours of sparky work (excluding any materials) will it take to make any cost savings negligible. Not Many. Boo.

So, what about appliance control at the "heavy users" directly? RJ12 connector on the bottom of pool controller -- lets ask the manufacturer - do they make an interface? No. Can I get the spec?
"All of our equipment uses an dedicated communication system designed purely for our own use.  Our comms system is not compatible with any other equipment and here is no protocol that we can release for external use."
Maybe not then. Perhaps try Breezair? Similar story.

So, everything has to be reverse engineered (needing skills and tooling) or you pay an integrator (no there aren't any) who will charge $$$$ to do this based on previous work. Current state: Ongoing as a spare time project. Mutter.

Example 2: Air Quality Egg.
Launched with a great flourish and fanfare 2 years ago. OK there were issues with producing the prototypes, but judging from the map, there's now quite a few of us with shields, eggs and more up and running.

Now what? where's the "one year on... report with a few pretty graphs. Even if its a case of "hmm variation is too high to make out anything reasonable" at least let your users know what's going on. Otherwise they'll get bored.

How can I compare my results with others around Perth? Not easily -- takes some hacking of the site to get the raw pachube^Wcosm^Wxively feed ID and then poll it and feed into gnuplot. End-User friendly? I think not.

I *like* the idea of IoT -- it does have the potential to help do clever things - but unless the glue and costs to end user are reasonable it's just not going to take off. Yet.


Popular posts from this blog

Growatt inverter monitoring with Raspberry Pi

At home we have a small (2.5KW - 10*250w panels) PV system to try and offset our daytime electricity usage. This is connected to a 'Growatt' inverter that handily has both RS485 (wierd 2 pin plugs) and RS232 (9 pin D connector buried under a screwplate) outputs.

With the firmware on ours (installed Sept 2013) it supports modbus-rtu over serial 9600 8N1.

I had done some initial digging and experimentation (as announced on Whirlpool) but never really got sensible values out.When my guruplug (via a long USB to serial adaptor) finally died and I shelved the whole thing. With the completion of the structured wiring though I finally got round to reconnecting it and starting again.

Small D9 Gender changer, + cisco console cable (all hail fleabay) gives a nice neat look on the outside, and in the garage I have another console cable plugged into the relevant patch outlet and a cheap usb-serial adaptor in a Raspberry Pi (which also has a GPS module connected, acting as a PPS NTP master)

Publishing DHT22 data via MQTT with an ESP8266

Some time ago I picked up a couple of ESP-01 modules with the intention of using them as wireless temperature/humidity sensors coupled with a DHT22.

Initial investigations took place at the Perth Artifactory "Arduino-U" evenings - I managed to put on a nodemcu lua firmware and found a few (varying) dht22 libraries. however I couldn't ever manage to get it to consistently publish the information to my message broker - it'd do one or two and then lock up. I dug it out again recently and decided to have another go - especially as Pete Scargill seemed to be having success with them (running native C).

So trying to 'revert' to a newer espressif release turned out to be non-trivial - installing the relevant toolchain needs multiple bits. I gave up and noticed that there was a newer (0.9.6-dev_20150704) nodemcu release, so I gave that a try.

First discovery - There's native support for the dht sensors in the firmware, so to get the current values all you need is…

Pretty Colours via MQTT

What does a geek do when they have some spare RGB LED strip (addressable WS2812B) and some cheap nasty LED devices? LED transplant time...

So, first to go was the LED glass prism stand received as a christmas present - out went the potted pcb with three fading LEDs, and in went a single piece of RGB strip fixed in place with a hot glue gun.
wire comes out the bottom and goes to a nanode.
So far so good, but I don't just want fixed or fading colours so time to revisit an IoT idea: Cheerlights

The cheerlights API defines 10 colors that can be set, but I want the possibility of sending any RGB value, so I created @FakeCheerlights as an MQTT series of topics on the broker


which contain the hex RGB value, the identified colour name and the raw tweet.

A separate script (running on the NAS) uses the twitter API via tweepy to follow the twitter stream search for 'cheerlights' and 'fakecheerlights…