Hello gang, someone sent me a message asking a very good question, what IS the correct CI-V voltage;

The answer is fairly simple 5VDC PtoP.

The idle CI-V voltage should be 5VDC and drops to near Zero when a bit is sent!

But, I have seen different OEN devices driving CI-V all the way down to 3.3VDC and work fine.

I strongly suggest you drive any projects at 5VDC to play it safe.

Please keep in mind, if you measure using a DVM, the resulting reading is false, since depending on the data your average voltage will vary a lot!
This should be properly be measured using a Scope NOT a DVM.

Please share your projects with the group.

Hope this helps

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Yes, I did initially drive my 7300 with CI-V messages at 3.3v logic and they appeared to be fine.  I later changed that to 5.0 v.