Hey there. I’ve integrated 433Mhz transmitters into my Particle Photon projects before. Luckily I had the RCSwitch library at my disposal which allowed me to just pass a couple of parameters to the library and turn some cheap switches on and off. I’ve recently removed everything from my GitHub for some personal reasons but if you’d like to take a look at the code for switches I can share it with you privately.
Here’s a project from @ogiewon , Maybe he’s had some more experience with other 433Mhz devices since he made this.
I feel like somebody else has done what you’re trying to do, but since Somfy always seemed unreasonably priced I never payed attention to any of the Somfy related threads.
Good luck, reach out to me if you’re still lost after some digging.