I have a Raspberry Pi doing data logging of my CV instalation, gas & electricity usage:

• The temperature using SPI using ​this guide.
• The Intergas CW6 using ​https://github.com/rickvanderzwet/IntergasBoilerReader
• The Landis + Gys E350 meter using ​https://github.com/rickvanderzwet/IntergasBoilerReader
• The Growatt 1500S using ​https://github.com/rickvanderzwet/GrowattReader