Trailer Wiring Question - Diff between hazards and brakes?

[davepl]

I'm trying to build a hidden LED strip for the back of my truck that does signals, brakes and backup lights. I have it all working in software, but when I went to wire it I ran into an issue:

On the 7-pin trailer connector, other than the electric brake, there's not a line for "Brake". Just park lights, left signal and right signal.

What I'm wondering is how do I know if the user has hit the brakes or turned on the hazards? In both cases it would seem that both rear signals light up at the same time. But that's the same as braking.

As it stands now I was thinking that I'm going to wind up a system that, when either the brake or the hazard is on, assumes it brake. I'm thinking I have to conclude braking when both the left and rear signal are on.

Is there something I'm missing? Some other way to tell hazard from brake at the connector?