After succesfully setting up my RPi as a gateway and setting some GPIO pins as in and out but also added an Ikea Tradfri lamp, I am now taking my first steps into creating an add-on/adapter for I2C on the Raspberry. Because there are so many I2C devices available like temp, humidity, pressure, light etc I think it might be very usefull to get that kind of information availalbe. So one can drive AC, ventilation, blinds etc based on the reading. I started with the BME280. There is no corresponding type that matches its functionality and for the time being I am mis-using the smartPlug type. But I see that one can create its own type using JSON-LD. What I can not figure out is where you need to add/define this extra type. Who can help me out here?