What about DMX?
Question: Why don't you use one for the serial ports to generate a DMX signal to control lights ? then you could control a lot more and don't have to mangle with 240V :)
Answer: Thank you for this input! It's an explizit target of this project to control something "big", so I don't see an other way than controlling 230V via relays. I'm not afraid of handling 230V ;-) And there is no problem to control up to 128 channels via I2C.
Can you explain your idea in detail? What should you way to trigger a village-illumination?
DMx is a standardized protocol to control lights (), you can control on/off lights in a relay style (see ), or automated/intelligent lights. I will probably bring some to the Camp (like ). you can control color, movement etc... there is an ethernet version of this called ArtNet too :)
Ok, I understand! I want to use I2C, because I want get a feeling for it. My roadmap is to attach other components such as Real-Time-Clock and GPS-Sensor, which are although available as I2C. After that, I want write a software that monitors the current radio-spectrum around me and write it down with the current time and gps-position. But this is a after-camp-plan :-)
I'll solder all the pins on my rad1o, so you are very welcome to attach an DMX-Device to it. Are you able to write the C-Code to trigger this DMX-Components via radio-commands?