Designing and building cars is easier now. It’s not magic. It’s communication standards.
Take the instrument cluster. That’s the cluster of gauges and lights in front of the driver. It gathers data from various vehicle parts. The ECU knows coolant temperature. It also knows engine speed. The transmission controller knows vehicle speed. The ABS controller knows if the brakes are failing.
These modules don’t keep that info to themselves. They send it onto the communications bus. Several times a second, the ECU sends a packet. The packet has a header. The header is a number. It identifies the data as speed or temperature. The data is a number corresponding to that value.
The instrument panel has its own module. It watches the bus. It looks for specific packets. When it sees one, it updates the gauge.
Most carmakers buy clusters from suppliers. The supplier designs them to spec. This simplifies things. It’s easier for the carmaker to tell the supplier how each gauge works. In the past, you had to explain the wire. You had to describe the varying voltage between 0 and 5 V. You had to explain that 1.1 V equals 30 mph.
Now, you just provide a list of data packets. The carmaker ensures the correct data goes onto the bus.
This is easier for the supplier too. They don’t need to know how the speed signal is generated. They don’t need to know where it comes from. The cluster just monitors the bus. It updates the gauges when new data arrives.
These standards make outsourcing simple. The carmaker doesn’t worry about driving each light. The supplier doesn’t worry about signal origins.
