I am NOT opposed to CAN, LIN, single ended or differential serial, etc. It's just a progression of technology.
Did you know there are CAN lightbulbs? Yup. No switches. Switching element is in emitter itself. Sounds like a lot of overkill. But is it? Common database to headlights. Turn lights on, turn lights off. Functions that seem to be easier with a switch or relay. Bulb can report when emitter is burned out. That requires sense leads between bulb circuit and an ecu somewhere, either detecting voltage drop, current flow, or passing a sense current. At least 1 more wire needed. 3 wires needed now. I foresee bulbs being able to report degradation, color temperature, brightness (computed) functionality if not already there. But, back to basics. For Headlights, 2 switches needed (on/off local, on/off high, perhaps with interlock). Parking / Marker lights. Another switch. Turn signals need a switch. Brake lights need a switch, as do dome lights, fog lights, bed / trunk lights.
8 switches, and associated wiring, to provide basic lighting control. Or 1 database.
What I found most irritating, at least on my Yukon, is inability to interact with databus. GM has held their secrets closely compared to Ford. You can't interface with GM without a Tech2 at a minimum. Ford needs a HSCAN / MSCAN adapter and 3rd party software (Forscan). Both inexpensive. Mopar provides upfitter CAN interface in several of their vehicles that is available direct or buffered. Hmm, maybe that would be Mercedes as I am referring to Sprinter vans made / badged by Mercedes, Dodge, and Freightliner. And better, their requirements to interface, what shouldn't be touched, etc are published.
Did you know there are CAN switches? Yup. Press a switch, and datastream is generated addressing intended device or sending command / request to centralized controller. Similar with relays.
Member of my extended family had an old Mercedes sedan. 5 cylinder diesel. Windows, door locks were not digital. They weren't even electric, but still powered. How? Vacuum. Vacuum operated door locks and windows. Very thankful not to have to maintain THAT.
If tools were more common to layperson (being PC there ;) ), I think there would be a much difference attitude towards CAN technology and derivatives as well as predecessors.
Perhaps I am unique. I have the idea that if I own something, I should have complete control over it. My phones are rooted. I use Linux (not very well). My F150 had several features added, others turned off because I desired. Heck, I am learning about IoT zigbee and other home mesh networks in relation to doir locks, cameras, lighting control. Starting to lesve behind X10 ( heavily invested).
Bought Yukon because can do same thing albeit with Tech2. Except that mine was 3 months too new, and Tech2 is very limited. Now would have to pay $49/3 days subscription.
Didn't know about CAN requirement. Makes sense as vehicles now have Blackbox ability and cameras for traffic interaction.
Time marches on.
~SD
