cheap Chinese Z-Wave Sensors and Home Assistant…

cheap z-wave door sensor
cheap z-wave door sensor
I was looking for sensors that allow to monitor the status of a door. Typically those are magnet triggered switches that send some sort of signal when the magnet moves away and comes back. I wanted something based on Z-Wave. I’ve already light switch relays that are running on Z-Wave and am very happy with them. Z-Wave is on the pricier end of RF-devices. 433Mhz switches would be much cheaper, but Z-Wave offers nicer handling and hopefully more reliability.

Many of these sensors come in at around 40€. That is quite pricy so I opted for the cheap chinese solution at around 13.5€ per piece. You just have to be patient: 4+ weeks delivery time.

Setup into Home Assistant was straight forward. Add the device to the Z-Wave network via the web interface, rename it to mydoor… but then… How does the device report ‘door open’? The binary sensor that showed up, did nothing.

After some fiddling and searching I found that the sensor.mydoor_access_control changes it’s state rather unspectacularly from 23 to 22. It’s so inconspicuous that I didn’t notice the change the first few times I kept looking for changes.

Perfect! there is something we can use to integrate it to Home Assistant for automation and other stuff. Luckily there are templates that allow us to turn this into a binary sensor which is more useful in automations.
Add this to your configuration.yml:

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binary_sensor:
  platform: template
  sensors:
    door1:
      device_class: opening
      friendly_name: 'Haustür'
      value_template: >-
        {%- if is_state("sensor.mydoor_access_control", "22") -%}
          True
        {%- else -%}
          False
        {%- endif -%}

this can then be integrated into an automation like this:

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automation:
  alias: "coming home"
  hide_entity: False
  trigger:
    platform: state
    entity_id: binary_sensor.door1
    from: 'off'
    to: 'on'
  condition:
    condition: sun
    after: sunset
  action:
    - service: homeassistant.turn_on
      entity_id:
        - switch.main_light

that’s it. hope this helps.

thanks to @Tinkerer from the Home Assistant chat group for the help.

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Home Automation with Python…

I gave a talk at Grazer Linuxtage 2017. It’s about Home Automation and how you can use Python to realize it.

The talk covers a simple example of a DIY sensor that runs MicroPython. Finally I give a short introduction to Home Assistant, a Python Home Automation Hub, that allows you to integrate with hundreds of devices. Home Assistant offers integrations to light switches, smart lights (Hue, Trådfri, Lightify,…), door sensors, heat control units, and many others.

There is a video of my talk on my Youtube channel:

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HOWTO setup your very own Jabber server…

XMPP (aka Jabber) in combination with OTR is a secure way to chat with others. There are some public servers available, but their popularity centralizes the infrastructure and leaves single points of failure. A recent example is Chaos Computer Club’s Jabber server (jabber.ccc.de) which was down for some days between Christmas and New Years 2014/2015, as a consequence of a DOS attack.

I’ve been setting up a Jabber server of my own on my Raspberry Pi. Here is how you can too:
Continue reading HOWTO setup your very own Jabber server…

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Fail2ban country statistics…

I was lucky enough to seize a “Raspberry Pi Colocation“-slot for my Raspberry Pi.

To secure it further I just recently installed fail2ban.
The software basically detects login attempts and blocks the IP for some limited time in the future. This prevents a depletive password guessing for server logins.

I was interested in the password-guessers` country of origin. Now I can confirm, at least for my Raspberry Pi, that most attacks come from China.

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    110       CN
      2       UA
      2       RU
      2       DE
      1       VN
      1       PE
      1       KR
      1       CZ
      1       BD

the quick and dirty command for this looks like this: (you need to have ‘whois’ installed)

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for i in `sudo cat /var/log/fail2ban.log | sed 's/.*[Bb]an \(.*\)/\1/' | sort | uniq | cut -d ' ' -f 1 | grep "\."`; do
  echo $i; whois $i | grep country\: |head -n 1 >> fail2ban_ctry.log ;
done
cat fail2ban_ctry.log fail2bancry2.log | sed 's/country:  //g' |sort | uniq -c |sort -nr

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Murstrom Podcast…

Nur eine kurze Ankündigung:

Ich habe angefangen zu podcasten.
Der Podcast an dem ich mitwirke heisst mur.strom. Wir besprechen diverse Themen zu Technik und Gesellschaft und senden in unregelmässigen Abständen. Die erste Folge mit meiner Komoderation ist Folge 13. In Folge 3 war ich einmal als Gast vertreten. Unsere Werke sind unter der CC-BY Creative Commons Lizenz auf der Webseite herunterzuladen und dürfen natürlich frei (unter Namensnennung) im Netz verteilt werden. So sehen wir es natürlich gerne wenn ihr unseren Podcast per BitTorrent herunterladet und zum download anbietet. 🙂

Wer gerne regelmässig zuhören möchte, dem kann ich die Android App AntennaPod empfehlen. Hier kann man unserem Podcast-Feed automatisch ‘zuhören’. Einfach die mur.strom URL eingeben und abonnieren. In den Einstellungen das automatische Herunterladen aktivieren und die neuesten Episoden sind dann automatisch auf dem Handy und lassen sich abspielen wenn man Zeit hat sich diese anzuhören.

Die aktuelle Episode, die erste mit mir, behandelte Bitcoin, das derzeit sehr gefragte online Geld. Die Folge kann man sich auf der Podcast Webseite herunterladen. Hier der direkte Link zur Bitcoin Episode. Und für alle Torrent Freunde: hier ist der icon-magnet Magnet Link zur aktuellen Bitcoin Episode. Wer Themenvorschläge hat oder Interviewpartner zu einem spannenden Thema sein will, darf sich gerne bei mir melden.

Die nächste Episode ist auch schon im Kasten und sollte demnächst erscheinen. Viel Spass beim hören.

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