Domotica because mosquitoes

Mosquitoes

To combat mosquitoes I once had a mosquito net. Those nets are usually awful; they hang from one point in the middle and then extend over your bed. Meaning that your bed turns into a cramped igloo tent. One exceptional hot week in The Netherlands resulted in some mosquitoes bites. The refreshed mosquito annoyance resulted in the discovery of rectangular mosquito nets, see e.g. this example product (I bought a different one btw). It basically adds straight walls and a ceiling around your bed. The net can be removed pretty easily once summer is over. It’s a pretty cool solution with two drawbacks: a) difficult to combine with a ceiling fan b) difficult to combine with a hanging lamp.

A fun solution to the lamp problem is to replace the light with remote controllable LED panel, mostly because why not. And so the lamp was replaced with an Ikea LED panel after which the rectangular  mosquito net was installed. The LED light is remote controllable. You get a pretty cool remote control with it, one you can install against a wall but is magnetic so you can still take the remote control with you. The Ikea LED light uses a communication protocol called Zigbee. This protocol is one of the various home automation protocols out there. The decision for buying the Ikea LED panel was mostly made because of interest into Zigbee.

Communication methods/protocols

For personal use the most common home automation methods/protocols seem to be:

  • Zigbee
    As mentioned. It works around 2.4Ghz (has multiple channels). Battery efficient. Mesh network. It should support a huge amount of devices, though range is less than Z-Wave Plus. Range could also be restricted due to interference with 2.4GHz Wi-Fi .
  • Z-Wave Plus
    Similar to Zigbee. It works around 900MHz, exact frequency differs per region. Battery efficient. Also uses a mesh network. There’s a huge amount of devices using Z-Wave Plus, though they tend to be more expensive than any other method. Due to using 900MHz it goes through walls easier than e.g. Zigbee or Wi-Fi.
  • Wi-Fi devices
    They mostly use 2.4GHz and support slow Wi-Fi b/g/n. Most of these devices use a chip called ESP8266. These devices are often not as power efficient as Zigbee/Z-Wave Plus so seems this is not a good choice for anything battery operated.
  • 433MHz
    Various devices work on the frequency 433MHz. They’re usually battery efficient, though (it seems?) there’s no real standardized protocol so aside from the frequency it depends on the service. A lot of the cheap ‘turn all these lights on/off’ use this frequency.
  • MQTT
    This is purely a protocol like e.g. HTTP or SSH. Its origin is from 1999. It doesn’t define how the data is transported (e.g. wired or wireless xx G/MHz), purely focusses on the protocol.

Security

Although a few methods use encryption it doesn’t mean that they’re secure. E.g. Zigbee apparently is NOT secure against replay attacks, though the newer Zigbee v3 should be. The Wi-Fi devices by default are often “cloud connected”. The 433Mhz devices lack any encryption and it’s quite easy to influence things. MQTT has authentication and it could use encryption but appears it’s often not available on devices. Without encryption probably anyone on the same network can just use a network sniffer to capture the MQTT login details. The list of security issues is pretty extensive. It’s best to always assume someone could takeover anything connected to any Domotica which has wireless functionality. Same for a wire but at least it requires slightly more effort.

Free software

There’s various free software available for Domotica. A list of a few nice ones:

  • Home Assistant
    Tries to ensure it’s NOT “cloud connected”. You need a Raspberry Pi or some 24/7 on machine to run this on. This software supports loads of devices, including loads of Zigbee hubs, MQTT, Z-Wave Plus controllers, etc. There’s Hass.io for easy installation on a Raspberry Pi.
    Aside from Home Assistant there are loads of alternative free software options.
  • Tasmota firmware
    Alternative firmware for ESP8266 devices. It seems pretty much all Wi-Fi b/g/n-only devices have an ESP8266 chip in them. The Tasmota firmware is NOT “cloud connected”, though it does rely somewhat on the internet, e.g. NTP for time synchronization. It adds support for MQTT, KNX, rules, timers, etc. The rules and timers would allow you to have the ESP8266 device itself know when to do something instead of having Home Assistant telling the device to do something.
    The big drawback is that it’s not easy to flash this firmware on most of the ESP8266 devices. It usually means taking something apart, soldering, etc. Fortunately the firmware is able to auto update itself making it a one-off hassle.
    Aside from Tasmote I noticed a few other similar ESP8266 firmware options, each with their benefits and drawbacks. Tasmota seems the most used/popular.
  • Zigbee2mqtt
    This software consists of two parts: One part is the real Zigbee2mqtt software, the other part  is firmware.
    The combination of both bits allow you to directly control Zigbee devices instead of needing to rely on the various Zigbee hubs. Often a Zigbee hub can only control a limited amount of devices, usually only within the same brand. Zigbee2mqtt supports way more devices than most of the Zigbee hubs. It then transforms this into MQTT.
    The drawback is that you need various components plus some tinkering, though the website explains what to do quite well. The site suggests to use a CC2531 chip, though I prefer the CC2530 chip. This as the CC2530 allows you to use an antenna. The CC2531 is easier to use and has an integrated antenna (worse range, 30m line of sight). I highly prefer a better range (60m for CC2530). Hopefully within 6 months better chip solution will become available.
    Another drawback is the limited amount of devices directly supported by the CC2530 or CC2531 chips. After 20-25 directly connected devices you might run into issues. To use more devices you’ll to have some Zigbee routers. It’s best to plan this ahead and plan for some non-battery operated Zigbee devices (Zigbee routers).
    For using Zigbee2mqtt, one possibility would be to have a chip with Zigbee2mqtt connected to a Raspberry Pi (or any other device with Home Assistant), another option is to combine it with a Wi-Fi chip and operate it independently.
    Aside from translating Zigbee to MQTT the firmware also allows you to create a Zigbee router. This to extend the range of your Zigbee network. The cost of such a router is only a few EUR at most. Easier solutions are either any Zigbee device connected to electricity (most are then a router), or a signal enhancer from Ikea for 9.99 EUR,.

Devices

I noticed a few nice devices. There might be many more nice ones out there. One way of figuring out which options are out there is to browse the supported devices list by zigbee2mqtt.

  • Zigbee Ikea TRÅDFRI
    I like their remote, their LED panel and their LED lamps. They also have various sensors, but they seem quite big compared to other solutions.
  • Zigbee Xiaomi/Aqara sensors
    They used to be dirt cheap until AliExpress raised all of the prices. The ones I like are their window/door sensors, shock sensors, motion sensor plus their magic cube.
  • Wi-Fi BlitzWolf BW-SHP6
    I like their plugs because they’re low cost, small footprint plus they still have a button on it making it easy to keep a physical way to turn the device on. The BW-SHP6 is a small EU plug which doesn’t take up too much space and allows up to 2300 Watt. There’s also the BW-SHP2 but I’d use the Osram smart+ plug over the BW-SHP2. You’re able to flash the Tasmota firmware on both the BW-SHP2 as the BW-SHP6, though it’s quite difficult for the BW-SHP6.
  • Osram smart+ plug
    This is a Zigbee plug with a button (Ikea one lacks a button).
    Drawbacks: bigger than the BW-SHP6
    Benefits: it speaks Zigbee, it’s a Zigbee router (extends your Zigbee range), it supports 16 Ampere/3600 Watt, I hope/guess the standby usage is lower
    You can buy it pretty cheaply on Amazon.de, use Keepa.com to check if you have a good price. New it’s often 15 EUR. Osram also sells used ones on Amazon; it seems they’re basically new but without a box. The price for those are around 11.50 EUR.
  • Sonoff (Wi-Fi)
    Loads and loads of different low cost options.  They’re supported by the Tasmota firmware. Their Wi-Fi switches are about 5.50 EUR if you buy 3; a possible use case  is to make these part of an extension cord.
  • Shelly (Wi-Fi)
    These devices are small enough to hide them within your wall outlet. They’re supported by the Tasmota firmware. Do look at the Tasmota Wiki as the Shelly hardware has some issues. For wall sockets I’d prefer an obvious device over something hidden within the outlet.
  • QuinLED (Wi-Fi)
    These aren’t devices, more like complete design for a device. The website extensively explains not only the device designs but also tools and equipment, LED strip advices, recommendations, guideline on what tools and equipment to buy to create these devices, etc.
  • Z-Wave Plus devices
    They’re so many nice devices which do not seem to have a Wi-Fi or Zigbee equivalent. E.g. 300Watt dimmers (Zigbee seems limited to 30Watt). The devices are way more expensive though; easily pay 70+ EUR per device/sensor.

Price

Price wise, it might be good to buy a device (“hub”) with support for all the Zigbee devices, Z-Wave, Wi-Fi, 433MHz, etc. This as building everything yourself might not even be cheaper if you’re only building it once. This as you might need to buy loads of things: soldering equipment, wire stripper, up to possibly a 3D printer. That would be less fun though!

That said, it’s a bit unfortunate that to really integrate everything together requires too much knowledge. I’d like a more out-of-the box type of solution. Something I’d be comfortable with giving to family that’s easy to use, works well and is still free software.

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