PI Home Connect (yet) a home automation for Raspberry Pi project

At the beginning of year 2015, a good resolution for me is the start of a modest home automation project : PI Home Connect

PiHomeConnect (encore) un projet domotique pour Raspberry Pi

The objectives of the project are simple :

  • Learn ! Des projets comme celui-ci il en existe des dizaines tous très bien conçus et performants mais commencer de zéro permet de se confronter aux problèmes de base et moi j’aime bien 🙂 En 433Mz comment transmettre des données, should be secure protocol, How to save the battery up to not change weekly, etc.
  • Having something simple. I will not be able to control everything (I have no electric shutters, pool, water pump and other). Just start with probes that give me basic information : temperature, pressure, humidity, presence, etc.
  • A modest. It must be something simple without investing a fortune. As said My wife : “long live the DIY” !
  • Share with you, for those who want to participate in the adventure. I will publish articles and surely a base of knowledge in the form of a small wiki.
  • Have fun with the GUI. I want something elegant and design. The style is already selected, remains to make it dynamic with the collected data.

So here now is the first photo of the project. A DHT11 probe for temperature and humidity. The probe sends these data as well as the battery level via a 433Mz transmitter to an Arduino. It is optimized to rated energy for work to the minimum necessary (the LED is just for fun since it consumes) and thus save the life expectancy of the two AA batteries (in their beautiful packaging !)

PiHomeConnect (encore) un projet domotique pour Raspberry Pi - DHT11

For consumption, I lost 0.06V (3.02 instead of 3.08) 26 h knowing that 4 measures are sent all the 5 seconds. Removing the LED, passing the number of emissions to 3 and by ca that all the 5 minutes, autonomy should skyrocket !

Coté equipment :

  • An Atmega328 (It is programmed in 8 mhz with its internal oscillator)
  • A DHT11 (will be replaced by a DHT22 or other) and its resistance
  • A 433 Mhz transmitter
  • 2 AA batteries
  • Cables and a breadboard

This gives a cost of the probe around €5 (If you are ordering in quantity for several probes in Asia) without the cables and the breadboard. I find it really correct.

Soon for the continuation of the project ! Share your ideas and feelings in the comments !

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