[purisame]

From what I've read, you are supposed to become an "HDMI Adopter" to legally sell products that use HDMI. There's a flat annual fee plus a per device royalty fee. Not sure how well enforced it is, since there are over 1,000 terminated adopters: https://hdmi.org/adopter/terminated. I wouldn't be surprised if some of their products are still on Amazon and other places.

The FPGA I'm using has HDMI and was made by Arduino, but they are not an HDMI Adopter: https://store.arduino.cc/usa/mkr-vidor-4000. "Raspberry Pi Trading Ltd" is one though.

There's a parameter to make the output be DVI only if it's a concern, I'll make a note of this in the README.

[MatthewWilkes]

I know some small projects are having a lot of trouble with this, because using only modules from fully paid-up adopter doesn't exempt you if you ship an end-user product that uses HDMI.

For example, the F18Amk2 project at https://atariage.com/forums/topic/280138-f18a-mk2/ which is implementing a TMS9918A has hit this problem.

I am inclined to agree that enforcement isn't 100%, but wanted to flag this up as it's relevant to your users. Thanks for adding the note!