Showing posts with label eco. Show all posts
Showing posts with label eco. Show all posts

Thursday, 6 December 2018

Green Millhouse: OK Google, turn on the living room air conditioner

My Broadlink RM3 IR blaster has been working pretty well, so I thought I'd share how I've been using it with a couple of IR-controlled air conditioners in my house, to control them with the Google Home Assistant via OpenHAB.

The RM3 sits in a little niche that has line-of-sight to both these devices (a Daikin in the living room, and a Panasonic in the dining area). Using the RM-Bridge Android app, the fun2code website and the method I've documented over on the OpenHAB forums), I've learnt the ON and OFF codes for each device, and put them into transforms/broadlink.map:
PANASONIC_AIRCON_ON=D3ADB33F...

PANASONIC_AIRCON_OFF=13371337...

DAIKIN_AIRCON_ON=F00F00FAAFAA...

DAIKIN_AIRCON_OFF=F00D00FAAFAA...

The "basic" way of invoking the commands is by using a String Item for your IR-blaster device, and a Switch in your sitemap, like this:

items/remotecontrollable.items:
String RM3_MINI {channel="broadlink:rm3:34-ea-34-58-9d-5b:command"}

sitemaps/default.sitemap:
sitemap default label="My house" {
  Frame label="Aircon" {
    Switch
      item=RM3_MINI 
      label="Dining Area"
      mappings=[PANASONIC_AIRCON_ON="On", PANASONIC_AIRCON_OFF="Off"]
  }
  ...
}

Which gives you this:

... which is completely fine for basic UI control. But if you want the Google Home Assistant (aka "OK Google") to be able to operate it, it won't work. The reason for this is that the Switchable trait that you have to give the item can only take the simple values ON and OFF, not a string like PANASONIC_AIRCON_ON. So while it *might* work if you named your remote control commands ON and OFF, you're hosed if you want to add a second switchable device.
The best solution I could find was to set up a second Item, which is literally the most basic Switch you can have. You can also give it a label that makes it easier to remember and say when commanding your Google Home device. You then use a rule to issue the "command" to match the desired item's state. I'll demonstrate the difference by configuring the Living Room aircon in this Google-friendly way:

items/remotecontrollable.items:
String RM3_MINI {channel="broadlink:rm3:34-ea-34-58-9d-5b:command"}
Switch AC_LIVING_ONOFF "Living Room Air Conditioner" [ "Switchable" ] 

Notice the "label" in the Switch is the one that will be used for Google voice commands.

rules/remotecontrollable.rules:
rule "Translate Living Room ON/OFF to aircon state"
when
  Item AC_LIVING_ONOFF changed 
then 
  val isOn = (AC_LIVING_ONOFF.state.toString() == "ON")
  val daikinState = if(isOn) "DAIKIN_AIRCON_ON" else "DAIKIN_AIRCON_OFF"
  RM3_MINI.sendCommand(daikinState)
end

This rule keeps the controlling channel (RM3_MINI) in line with the human-input channel (the OpenHAB UI or the Google Home Assistant input). Finally the sitemap:

sitemaps/default.sitemap:
sitemap default label="My house" {
  Frame label="Aircon" {
    Switch item=AC_LIVING_ONOFF label="Living Room On/Off" 
  }
  ...
}

I quite like the fact that the gory detail of which command to send (the DAIKIN_AIRCON_ON stuff) is not exposed in the sitemap by doing it this way. You also get a nicer toggle switch as a result:



The final step is to ensure the AC_LIVING_ONOFF item is being exposed via the MyOpenHAB connector service, which in turn links to the Google Assistant integration. And now I can say "Hey Google, turn on the living room air conditioner" and within 5 seconds it's spinning up.

Friday, 4 May 2018

Raspberry Pi 3 Model B+

My Synology NAS is coming up to 10 years of age, and asking it to do all its usual functions, plus run a few solid Java apps: ... was all a bit much for its 700MHz ARM processor, and particularly its 256Mb of RAM. Jenkins was the final straw, so I was looking around for other low-power devices that could run these apps comfortably. One gigabyte of RAM being a definite requirement. My Googling came up with Raspberry Pi devices, which surprised me as I'd always considered them a little "weak" as general purpose servers, more for doing single duties or as clients.

But that was before I knew about the Raspberry Pi 3, Model B+. This little rocket boots up its Raspbian (tweaked Debian) OS in a few seconds, has 1Gb of RAM and a quad-core 1.4GHz ARM processor that does a great job with the Java workloads I'm throwing at it. And look at the thing - it's about the size of a pack of cards:
A quad-core server with 1Gb of RAM, sitting on 3TB of storage. LEGO piece for scale. I wonder what 1998-me would have made of that!

With wired and wireless Ethernet, scads of USB 3.0 ports and interesting GPIO pin possibilities, this thing is ideal for my home automation projects. And priced so affordably that (should it become necessary) running a fleet of these little guys is quite plausible. If like me, you had thought the Raspberry Pi was a bit of a toy, take another look!

Monday, 2 November 2015

Green Millhouse - Hacking WiFi Power Points

I recently discovered Mr Money Mustache and his delightfully-entertaining take on frugality. Turns out I had independently come to some very similar conclusions (live close to work, ride a bike to work, minimise car ownership/usage, avoid borrowing) but he still offers a ton of new perspectives on saving money that I'm really enjoying.

An area in particular is running an efficient home. My first toe-dip in this area is shutting down (not putting-into-standby, shutting down) as many things as possible for as much of the day as possible. Being a geek, controlling some power-points via WiFi seemed like a great way to get started. Hence:
These $20 devices can be found on eBay and are controlled by an app that is only ever named in the user manual. This smells of "security by obscurity" and after further investigation I can see why...

My particular one (which was identical to the photo) was called a "Small-K" but you'll probably get the most Google-joy by searching for "Kankun" devices. There are a whole pile of different iOS and Android apps, with various brandings and/or success at translation into English.

There is an extremely troubling suggestion that the various Android apps do some "calling home" via some Chinese servers - this, combined with the fact that you have to tell your device your SSID and WiFi password, made me sufficiently uneasy that even though I have uninstalled the Android app (it was junk anyway), I'll be putting my smart plugs into a dedicated subnet that is unable to "get out of" my network. How?

Putting network devices in jail

I use DNSmasq on my NAS which gives me much more control over my DHCP than the usual on/off switch in consumer routers. The setup to make sure a particular device doesn't go wandering off out onto the interwebs just needs two lines of configuration in dnsmasq.conf, namely:
# Always give the host with ethernet address 11:22:33:44:55:66
# the name smartplug1,
# IP address 10.200.240.1,
# lease time 45 minutes, and
# assign it to the "jailed" group
dhcp-host=11:22:33:44:55:66,smartplug1,10.200.240.1,45m,net:jailed
Why 10.200.240.1? Well:
  • 10 because I like to have space ;-)
  • 200d is 11001000 which in my bitwise-masking permissions scheme means:
    • Firewalled FROM internet
    • Trusted WITHIN home network; and
    • Prevented from going TO internet (I've added that last bit flag since writing that old post)
  • 240d because it's 240-Volt mains power (geddit?); and
  • 1 because it's my first device of this type
Now for the part where inhabitants of the 200 subnet get jailed:
# Members of the "jailed" group don't get 
# told about the default gateway 
#("router" in DHCP-speak) 
#- this sends a zero-length value:
dhcp-option = net:jailed, option:router
And we can check this after rebooting the plug; in the DNSmasq logs:
dnsmasq-dhcp: DHCPDISCOVER(eth0) 11:22:33:44:55:66 
dnsmasq-dhcp: DHCPOFFER(eth0) 10.200.240.1 11:22:33:44:55:66 
dnsmasq-dhcp: DHCPREQUEST(eth0) 10.200.240.1 11:22:33:44:55:66 
dnsmasq-dhcp: DHCPACK(eth0) 10.200.240.1 11:22:33:44:55:66 smartplug1
.. and after logging in to root@smartplug1:
root@koven:~# ping www.google.com
PING www.google.com (220.244.136.54): 56 data bytes
ping: sendto: Network is unreachable


Avoiding The Chinese Entirely :-)

Now that I've been through the pain of the Android-app-setup dance (which sucked, and never correctly registered the presence of the WiFi power point in its own app), I can heartily recommend just SSH'ing into the plug and doing it manually. It was at this point that I came across the awesome OpenHAB project, which is an open-source universe of "bindings" for devices such as these, with the nice UI required for a high WAF. Much more OpenHAB-hacking to follow!