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diff --git a/posts/homeauto.md b/posts/homeauto.md new file mode 100644 index 0000000..2eddde3 --- /dev/null +++ b/posts/homeauto.md @@ -0,0 +1,229 @@ +[meta]: <title> (My home automation adventure) +[meta]: <subtitle> (How to make your house a shitty utopia) +[meta]: <author> (Loek) +[meta]: <date> (August 17 2021) +[meta]: <tags> (home automation, raspberry pi, software, hardware, hacking) +[meta]: <cover> (/img/homeauto.png) + +Home automation is cool, but it can also be scary. I want to try to convert my +existing bedroom lights into 'smart' lights that I can control using a home +automation system. + +I've tried two home automation systems so far: homebridge and home assistant. +Homebridge isn't really an automation system. It's meant to add unsupported +devices to *homekit*, but doesn't work with anything other than apple devices. +I've also tried (and am currently using) home assistant. It's a complete +replacement for the homekit ecosystem, and it can do basically anything, as +long as you're patient enough... + +The devices I'm going to try to automate are: + +- A random bluetooth RGB/white lamp I bought a couple years back +- An RGB strip under my bed my mom got me for christmas +- A gen 1 Philips LivingColors lamp from 2008 +- My Toshiba RAS-M10GKV-E2 air conditioning unit + +## The bluetooth RGB lamp + +This lamp is apparently another Chinese product that gets rebranded and sold +under different names. I bought mine as the "[Shada led's +light](http://leds-lightpro.com/node/4368)" (no the apostrophe isn't a typo). + +When scanning for bluetooth devices using `bluetoothctl` on Linux, it shows up +as an LE device called "Beken LED". + +I don't remember what search term I used when searching for it's bluetooth +protocol, but I landed on [this page](https://wiki.fhem.de/wiki/BEKEN_iLedBlub) +from a german website about home automation, where it's called the "BEKEN +iLedBulb". It documents which Bluetooth LE characteristics you need to write to +for the lamp to change color. + +The lamp has both [iOS](https://apps.apple.com/us/app/leds-light/id1058642950) +and +[android](https://play.google.com/store/apps/details?id=com.shada.ledslight&hl=en_US&gl=US) +apps available, though only the iOS app seemed to work. + +### Writing a homebridge plugin + +When I started out with this home automation business, I used homebridge +because I didn't know about home assistant yet. Developing plugins for +homebridge is actually pretty easy (after figuring out [how to get the plugin +to load](https://github.com/homebridge/homebridge/issues/2958)). The +documentation is pretty good, and it has typescript integration for maximum +/comfy/-ness. + +Because HomeKit doesn't support RGBW or RGBWW lights (lights that have both rgb +and dedicated white diodes), I chose to display them as seperate rgb and white +lamps inside the home app. + +[The plugin](https://www.npmjs.com/package/homebridge-beken) is pretty janky, +and requires some manual setup, but it worked very consistently for the single +week I used it for. + +### Converting the homebridge plugin to home assistant + +Now that I could control a single bulb using the home app and siri, I needed +more. The homebridge website allows for turning devices on/off, but doesn't +allow color changes. I also liked the idea of controlling the lights using my +phone, which runs android. + +Home assistant was the solution, so I went ahead and installed [home assistant +core](https://www.home-assistant.io/installation/linux#install-home-assistant-core) +on the Raspberry Pi 3B+ I'm using as a dedicated home automation hub. + +Upon opening it for the first time, I noticed it was much slower than +homebridge, but that's because it was installing a bunch of other stuff in the +background. After waiting for the background tasks to complete, I was greeted +with a very nice web interface. There were also already devices that I could +integrate immediately, like the downstairs chromecasts, and my Jellyfin server. + +Now I had to figure out how to write a plugin for home assistant. There's some +concepts in the home assistant ecosystem that I didn't quite understand, which +made searching where to start harder. + +**Integrations** are like plugins, they allow you to *integrate* an unsupported +device into home assistant. Integrations create **devices** which create +**entities** (device properties). Certain entity types can only be read (like +`sensor`), and others can also be updated / written to (lights). + +The documentation for creating entity integrations is pretty poopy, and I +mostly used other plugins on GitHub as reference material. The home assistant +plugin code is available on +[GitHub](https://github.com/lonkaars/homeassistant-beken) and [my personal git +server](https://git.pipeframe.xyz/lonkaars/homeassistant-beken/about). + +## The RGB gamer bed + +I was originally planning to control this strip using IR remote emulation, but +I remembered a friend of mine still had an esp8266 laying around. So I went the +extra mile and wanted to try to create a new driver board for the strip +instead. + +### Opening the original driver + + + + + + + + + +### Making a custom driver board + +**I AM NOT AN ELECTRICIAN**. I looked on the internet, and I think this is just +a simple board with some mosfets and flash memory for storing the 6 custom +colors. The mosfets are the 3 big squares labeled Q1, Q2 and Q3. The way the +strip works is it gets +12v though the black wire, and then lights up when you +ground any combination of the red, green, and blue wires. The strip dims using +pulse width modulation. The mosfets act like an electronic switch, and control +the grounding of the colored wires. + +I'm going to salvage the mosfets, and barrel plug from the original driver +board, and resolder them on a perfboard with the esp8266 so I can control them +over WiFi. The schematic I'm using comes from +[instructables](https://www.instructables.com/WiFi-Controlled-RGB-LED-Strip-With-ESP8266/). + + + +--- photo of thing in breadboard --- + +--- photo of thing in perfboard --- + +### Beautiful dremel work + +I wanted to use the original enclosure instead of a tupperware container this +time, so I used my dad's dremel to create holes for the esp to fit. + + + + + +As you can see I did a great job :^) + +--- photo of perfboard in case --- + +### ESP firmware + +The firmare I wrote for the esp is available on +[GitHub](https://github.com/lonkaars/esp8266-rgbstrip) and [my git +server](https://git.pipeframe.xyz/lonkaars/esp8266-rgbstrip/about), along with +the home assistant plugin +([GitHub](https://github.com/lonkaars/hass-esp8266-rgbstrip), +[cgit](https://git.pipeframe.xyz/lonkaars/hass-esp8266-rgbstrip/about)). I used +the [espressif ESP8266_RTOS_SDK](https://github.com/espressif/ESP8266_RTOS_SDK) +toolchain with gnu make as my build system. + +It just connects to your specified wifi network under your specified hostname, +and listens on port 80 for regular http requests. Here's how to use it without +the home assistant plugin: + +```bash +# get color +curl http://hostname/ + +# set color rrggbb color (hex) +curl -X POST -d "0000ff" http://hostname/ +``` + +Some cool features this firmare has are: + +- Linearly interpolated color transitions with customizable transition and step + duration +- Brightness curve correction (makes difference in brightness more pronounced + at higher brightness levels by using a parabolic curve) + +I'm not sure if the more popular [ESPHome](https://esphome.io/) firmare has +these features, but I wanted to have a go at writing my own firmare anyways. + +### Safety + +Because the esp8266 is a pretty basic microcontroller, it doesn't use https or +ssl for encryption. To protect from people in my house wanting to control my +lights, I used the raspberry pi's on board wifi module to create a hidden +private isolated wifi network for this, and all future IoT devices in my +bedroom. I'm using `hostapd` to create the wifi network, and `dnsmasq` for +assigning ip addresses and hostname resolution. Here's the config file for +`dnsmasq`: + +``` +no-resolv +interface=wlan0 +dhcp-range=10.0.0.1,10.0.0.16,24h +server=8.8.8.8 +``` + +And here's `hostapd`'s config file: + +```bash +# common settings +interface=wlan0 +driver=nl80211 +ssid=network_name_here +hw_mode=g +channel=1 +macaddr_acl=0 +auth_algs=1 +ignore_broadcast_ssid=1 +wpa=2 +wpa_passphrase=network_password_here +wpa_key_mgmt=WPA-PSK +rsn_pairwise=CCMP + +# raspberry pi 3b+ specific settings +ieee80211n=1 # 802.11n support +wmm_enabled=1 # QoS support +ht_capab=[HT40+][SHORT-GI-20][DSSS_CCK-40] +``` + +Very complicated stuff... + +## The Philips LivingColors lamp + +[This](http://www.knutsel.org/2009/01/01/livingcolors-1st-generation/) article +describes all the research that went into reverse-engineering the lamp. + +## The Toshiba air conditioning unit + +IR remote emulation with LIRC + |