[Sonoff-Tasmota_KNX](https://github.com/ascillato/Sonoff-Tasmota_KNX) is a modification for [Sonoff-Tasmota](https://github.com/arendst/Sonoff-Tasmota) to add a basic functionality of the [KNX IP Protocol](https://www.knx.org/knx-en/index.php).
The [KNX IP Protocol](https://www.knx.org/knx-en/knx/association/what-is-knx/index.php) is an _international open standard_ for smart homes and smart buildings automation. It is a decentralized 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.
* [ESP KNX IP Library (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), [PR #52](https://github.com/envy/esp-knx-ip/pull/52), [PR #54](https://github.com/envy/esp-knx-ip/pull/54) and [PR #55](https://github.com/envy/esp-knx-ip/pull/55)
* [ESPAsyncUDP Library](https://github.com/me-no-dev/ESPAsyncUDP) with the modifications requested on [PR #21](https://github.com/me-no-dev/ESPAsyncUDP/pull/21). This Library is used by ESP KNX IP Library.
There are multiple possible configurations. Here are explained just a few as example. The options for selecting relays, buttons, sensors, etc. are only available if were configured on _Configure Module Menu_.
To configure KNX, enter on the Configuration Menu of Sonoff-Tasmota and select Configure KNX.
**1) Setting Several Sonoff to be controlled as one by a Home Automation System:**
We can set one of the group address to be the same in all the devices so as to turn them on or off at the same time.
In this case, so as to inform the status of all the relays to the Automation System, just one of the devices have to be configured as the responder. If you use the same Group Address for sending and receiving, you have to take into account not to make loops.
**2) Setting 2 Sonoff to be linked as stair lights:**
We can set one device to send the status of its output and another to read that and follow. And the second device can send the status of its button and the first device will toggle. With this configuration we can avoid to make a loop.
Just setting one device to send the push of a button, and the rest just use that value to turn them on. In this case, there is no toggle. Every time the button is pushed, the turn on command is sent.
We can configure to send the value of temperature or humidity every teleperiod. This teleperiod can be configured. See Sonoff Tasmota [wiki](https://github.com/arendst/Sonoff-Tasmota/wiki/Commands). It is recommended also to set the reply temperature address.
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.
