I am currently designing a module (a led sequencer), which I am unsure how to sell/distribute. In the end microcontroller could be any of megaAVR series (haven't figured out yet), currently developing on ATmega2560. Let's say I finish up the module with all the components and sell it to the client. The module will be in unprogrammed state.
Now every client will have different requirements, so the module have to be configured according to the client needs. To do this I will have a website set up, which then client will visit and set his requirements, (design animation patterns for each led, speed and what not) and the site will generate his hex file for him, which he will be able to download and upload himself to the module with USB ASP. Normally I would've just generated a .eep file instead of the whole hex file, but the configuration data could be so large that I can't put in eeprom. Hence the hex file.
Now the problem with this is that anyone can visit the site and get a hex file, the module is fairly simple just a micro with a voltage regulator, few inputs and outputs with transistor attached to drive the load, very easy to replicate.
So all this will be duplicated fairly quickly. What can be done to have some protection ? Like the hex file only uploads to the module which is only sold by me, not anyone else's ?
Any opinions ? or how would you do it if you had to ?