Home automation and IoT (Internet of Things )

have made tremendous progress in the last few years. The success and support for the Arduino platform, the availability of affordable transceivers and sensors had made things possible I only could dream about 5 years ago.

For a very long time now I was mostly driven by the wish to detect harmful situations in my home, like fire, water, gas, … and report that directly to me, wherever I am in this big world. E.g. I had a broken water hose during a 2 weeks holiday, which went unnoticed for several hours until a neighbour finally spotted it and could take action.

So this is how my sensor network looks today

My Hoem Sensor Network

Have a look at my Home Automation page for more.

Weekly Switch Clock

This is my weekly switch clock on basis of Arduino. I needed a weekly switch clock for my small aquarium. So the labels on the buttons are the German names for „Light“, „Filter“ and „Heating“.


  • use DCF77 for automatic time setting
    This eliminates the need to adjust the time because of „daylight savings“. Sorry, if you do not have DCF77 available you currently will have to change time manually.
  • use Real Time Clock DS3231 if DCF77 is not available
    a very precise RTC
  • 3 rc-switches
    Place the clock wherever you want. And of course no cables from switches to the clock
  • have 30 timers or more available
    The Arduino Mega has a 4KB EEPROM;
    with 30 timers, only 400 Bytes are used, so there is room for many more timers
  • 3.2 TFT touch screen for easy handling
    this should make handling easy enough that you do not need any manual at all
  • all settings and timers in EEPROM so they will survive a power loss
    This is what everybody expects but excludes the use of an AVR Arduino
  • Watchdog enable
    In case the clock hangs, it can recover on its own