Spending several years implementing various heat control systems using SMS, Java, Conrad CControl, and Raspberry Pi's, those projects have been superseded by a new pellet boiler with an integrated control unit accessible via VNC. Some programming is still needed for the integration into a Home Automation system.
Home Automation System
After using several Z-Wave base home control systems, the current system uses a Raspberry Pi 4 and Domoticz. This works better than the previous systems (more stable) and allows the integration of other Home Automation standards, such as IKEA TRÅDFRI, Philips Hue and others.
There are many non-proprietary, open source ecosystems such as Home Assistant, OpenHAB and Domoticz. Domoticz is a very light weight home automation system that lets you monitor and configure miscellaneous devices, including lights, switches, various sensors/meters like temperature, rainfall, wind, electricity usage/production, and many more. Notifications/alerts can be sent to any mobile device or email account. Domoticz is open source and available at Github.
Since the Z-Wave stations used where not really reliable, the Raspberry Pi Domoticz system uses an USB stick and OZW providing Z-Wave integration. Similar to other Z-Wave home automation platforms, some programming can be used using Lua on the Domoticz system.
Modbus is a serial communications protocol originally published by Modicon in 1979 for use with its programmable logic controllers (PLCs). Modbus has become a de facto standard communication protocol and is now a commonly available means of connecting industrial electronic devices. The integration of Modbus based systems (heat control, HVAC, etc.) is done using a REST based Web gateway implemented using ASP.NET and running on a Raspberry Pi.
The most common smart lighting systems are Philips Hue and IKEA TRÅDFRI. They are based on the Zigbee communication protocol, and to some degree can be mixed. Amazon, Apple, Google, and the Zigbee Alliance announced a new working group "Connected Home over IP" that plans to develop and promote the adoption of a new, royalty-free connectivity standard to increase compatibility among smart home products. Zigbee Alliance board member companies such as IKEA, Legrand, NXP Semiconductors, Resideo, Samsung SmartThings, Schneider Electric, Signify (formerly Philips Lighting), Silicon Labs, Somfy, and Wulian are also onboard.
More recently cheap WiFi based solution become readily available. Replacing most of (unreliable) Z-Wave devices using WiFi based devices from Shelly, was a fairly straight forward affair. Cheaper than Z-Wave devices, they are very easy to integrate into Domoticz using MQTT.