What is smarthomatic?

smarthomatic (SHC) is an open source home automation system providing a framework for building up a bigger network of sensors and actuators that all work together. It consists of several completely developed hardware devices you can build up yourself and the software running on those devices.

This project concentrates on hardware devices and their software (firmware), not on user interfaces to control tasks like web interfaces or smartphone apps. Nonetheless this system is designed to be easily integrated into such systems.

Read the story of how the project was born

Typical Use Cases


...and advantages over typical commercial products:

Simple and affordable

For basic setup, the base station and e.g. a temperature sensor are sufficient. All devices consist of few parts, are easy to build and reasonably priced.


You can extend the system with new sensors and actuators to support any new functionality you like.


As an open source project, the system can be changed any time. This ensures long-term maintainability.

Highly secure

Communication is AES encrypted. Even fake repeated commands from an attacker are ignored.


Commands for changing states of devices are confirmed with acknowledges. If a request is not answered, it will automatically be repeated several times by the sender.

You can use the system by simply entering commands through a serial terminal. The base station is connected over a USB virtual COM port or directly to a physical COM port. You can integrate this system into a home automation PC software to support complex control tasks.

What's New

  • (06/2024) Introduced new device Proxy, which can forward packets to devices too far away from the base station based on a set of rules.
  • (05/2024) Improved RGB Dimmer HW schematic and layout to support restart of RFM12 and to implement the needed HW changes for SW v0.13.0, so no HW patch is necessary anymore.
  • (05/2024) Corrected Power Switch HW layout to support restart of RFM12 in case of reception problems. The previous layout had a short circuit so that the RFM12 power pin was always connected to VCC 3.3V. The possible manual fix for PCB V1.1 is documented in the wiki. Additionally, battery voltage measurement is supported.
  • (07/2023) released v0.13.0:
    • General: Support "Deliver" message with which a device can ensure that the base station received it (used by controller device). Support 64 byte packets. Support ATMega1284 and 4kB e2p. Improve collision detection timing.
    • Controller: New device which acts as user interface. Supports LDC text display, RGB LED, speaker and buttons to navigate through a menu with options defined in e2p. Can be used as control interface for smart home functions.
    • Powerswitch: Support for On/Off-delay that is used when a status change is triggered by the optional switch. Put relais state into status message. Fix version status cycle.
    • RGB Dimmer: HW break! Pins for RGB leds changed to have common source code with controller device. Support "tone" and "melody" message to play (warning) melodies / alerts.
    • FHEM: Update modules to be used with new controller device. Use default baud rate of 115200. Avoid "require" keyword and "given/when".

Next Steps

  • build up roller shutter device