A lot of those steering wheel remote controls don't work as straight forwardly as that. Some already use a serial interface, others encode the data in different ways - some further investigation would be necessary before you would know exactly what's required.
That's interesting. I'm not sure his qualifies as a "steering wheel remote", though, since it's built-in to the car. It's an American car (a Dodge truck), so I assumed that it was low-tech (i.e., buttons connected directly to the factory radio via a wiring harness). I figured we'd just patch our serial device directly into the control wires. But if we can't get directly to the button control wires, you're right, we'll have to find out exactly what it's doing before diving in. Thanks for the heads-up.
In the meantime, I'm thinking of rigging up my own system on my car, by making and wiring up the buttons myself. Does anyone know of an existing device that does this?
-- Tony Fabris -- Empeg #144 --
Caution: Do not look into laser with remaining good eye.