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by mikestew 3883 days ago
If I'm paying tens of thousands of dollars for a car, how come they're using the cheapest possible components?

Save a dollar on the part, and you make a million cars, how much does that add up to? Or conversely, why spend more than you have to if the quoted specs do the job? What the hell am I going to do with four cores if I follow the well-written description above?

And I'd give your Raspberry Pi a lifespan of about a month if you were to strap it to the firewall of your car while you drive it. Less if you actually powered it up.

1 comments

You'd do it because the million dollars in parts is peanuts compared to the combined salaries of the engineers who are paid to have the specialized knowledge to do this, and the time it to bring up a new application/car. I know that a million dollars is lowball, but this same principle can be applied to other components and scaled up (to a point).

Potting electronics in epoxy isn't terrifically difficult, and would greatly increase the durability. I'm willing to bet that a potted Beaglebone Black (for its real-time subsystem) would do just fine in my engine bay for a very long time. The hard part would be getting a single large-pin-count plug coming out of it to handle all the inputs.

This point is actually kind of moot because for a long time the ECUs of cars were located in the passenger cabin with wires fed in through a grommet in the firewall.

I'd wager that the cost of replacing this system with some standard real-time platform is so monumental, it won't ever be done. Good luck getting the automotive equivalent of BSPs (board-support packages) running on any system other than this.

Where this gets interesting is when the people who actually know this system die start retiring/exiting the market. There will be a pretty strong incentive to 1) keep reusing the same system with no new development, 2) accept the lead time in training students/etc, or 3) start paying crazy salaries for people to go out of their way to learn it.

Cars are life-critical systems. If GM half-assed it by putting...

> a potted Beaglebone Black (for its real-time subsystem)

...into an actual production car, what happens when the thing breaks down and kills someone? Death, recalls, lawsuits, and massive brand damage.

> This point is actually kind of moot because for a long time the ECUs of cars were located in the passenger cabin with wires fed in through a grommet in the firewall.

Even in the passenger compartment, cars aren't exactly friendly environments for electronics. They have large temperature swings (from a controlled climate to very hot in summer or very cold in winter). So putting it in the passenger compartment doesn't necessarily moot concerns over withstanding extreme environments.

The first point was meant to illustrate that it's not good enough to say that it's okay to not innovate because there's no better hardware available. I'm not suggesting that GM would seriously put a potted development board inside a vehicle. TI can simply produce automotive-grade equivalents for them.

What I'm suggesting is that things like higher sampling rates of input sensors and more composability and reusability can be realized by a newer, more standardized and open approach to hardware.

I would also wager that the outcome of failure would be the same as with the traditional systems. GM shifts the blame onto the ECU development shop that it contracted out to make the hardware or software, or the QE shop that failed to pick up the failure.

Vehicle electronics are typically rated from -40C to 125C, although it's seen that they routinely fail even inside these margins. The BBB for example can have an operating temperature from -40C to 85C. There are also plenty of industrial boards that meet or exceed the requirements of automotive operating environments. Companies such as TI are (in part) releasing development boards (such as the BBB) to try to inspire innovation in these environments. The dev boards themselves aren't rated for it, but the platform can be.