Modification for [Sonoff-Tasmota](https://github.com/arendst/Sonoff-Tasmota) to add basic functionality of the [KNX IP Protocol](https://www.knx.org/knx-en/index.php).
The [KNX](https://www.knx.org/knx-en/knx/association/what-is-knx/index.php) IP Protocol is intended for smart home and smart bulding automation. It is a decentraliced system. Each device can talk directly to each other without the need of a central controller or server. Any panel or server is just for telesupervision and for sending requests. KNX IP Protocol uses a UDP multicast on _224.0.23.12:3671_.
Each device can be configured with group addresses as **2 / 2 / 1** and that address can be used for sending/receiving commands.
So, for example, if 2 devices that are configured with the **2 / 2 / 1** for turning on/off their outputs, and other device send _Turn ON_ command to **2 / 2 / 1**, both devices will turn on their outputs.
Several home automation systems have KNX support. For example, [Home Assistant](https://github.com/home-assistant/home-assistant) has a [XKNX Python Library](https://github.com/XKNX/xknx) to connect to KNX devices using a KNX Router. If you don't have a **KNX Router**, you can use a **Software KNX Router** like [KNXd](https://github.com/knxd/knxd) on the same Raspberry Pi than Home Assistant. KNXd is used by Home Assistant for reading this UDP Multicast, although KNXd has other cool features that need extra hardware like connect to KNX devices by Twister Pair, Power Line or RF.
* ESP8266 KNX IP Library [envy/esp-knx-ip async-udp branch](https://github.com/envy/esp-knx-ip/tree/async-udp) with the modifications requested on [PR#48](https://github.com/envy/esp-knx-ip/pull/48) and [PR#52](https://github.com/envy/esp-knx-ip/pull/52)
* [ESPAsyncUDP](https://github.com/me-no-dev/ESPAsyncUDP) Library, used by ESP KNX IP library async-udp branch). Please, use ESPAsyncUDP library patched with the [PR #21](https://github.com/me-no-dev/ESPAsyncUDP/pull/21)
Alternative firmware for _ESP8266 based devices_ like [iTead](https://www.itead.cc/) _**Sonoff**_, with **web**, **timers**, 'Over The Air' (**OTA**) firmware updates and **sensors support**, allowing control under **serial**, **HTTP**, **KNX** and **MQTT**, so as to be used on **Smart Home Systems**. Written for Arduino IDE and PlatformIO.
Current version is **5.12.0j** - See [sonoff/_releasenotes.ino](https://github.com/arendst/Sonoff-Tasmota/blob/development/sonoff/_releasenotes.ino) for change information.
- Only Flash Mode **DOUT** is supported. Do not use Flash Mode DIO / QIO / QOUT as it might seem to brick your device. See [Wiki](https://github.com/arendst/Sonoff-Tasmota/wiki/Theo's-Tasmota-Tips) for background information.
- Sonoff-Tasmota uses a 1M linker script WITHOUT spiffs for optimal code space. If you compile using ESP/Arduino library 2.3.0 then download the provided new linker script to your Arduino IDE or Platformio base folder. Later version of ESP/Arduino library already contain the correct linker script. See [Wiki > Prerequisite](https://github.com/arendst/Sonoff-Tasmota/wiki/Prerequisite).
- To make compile time changes to Sonoff-Tasmota it can use the ``user_config_override.h`` file. It assures keeping your settings when you download and compile a new version. To use ``user_config.override.h`` you will have to make a copy of the provided ``user_config.override_sample.h`` file and add your setting overrides. To enable the override file you will need to use a compile define as documented in the ``user_config_override_sample.h`` file.
