• 3 Posts
  • 766 Comments
Joined 1 year ago
cake
Cake day: June 23rd, 2023

help-circle



  • I recall when I bought my first hybrid that the dealer said there were something like 15 different computers controlling things, from the ICE engine to the transmission to the charging of the battery, etc. They weren’t networked together.

    I also once ran afoul of a software bug in the ECU of a Honda CR/V. That’s the embedded system that manages the whole operation of the engine - from fuel injection to timing to emissions etc. As they progress through model years they use different ECUs that require different software. Even though I work in IT, I wouldn’t feel comfortable trying to update it myself, given the different models, firmware revisions, etc. I was more than happy to take that car to a dealer to have them confirm my car had buggy software and to upgrade it to the right new version.









  • Used GPS on boats as early as the late 1980’s, back when selective availability was still a thing. For those unfamiliar with it, GPS was initially military-only, and when they allowed civilian use they were concerned that US adversaries could use it for precision attacks. So SA was included in the civilian version, which introduced a random error of up to something like 1000 yards.

    The truly ironic thing is that the US Coast Guard (a branch of the very military that created SA) saw the usefulness of GPS for marine navigation, but only if SA was removed. 1000 yards could easily mean the difference between a boat running aground (or worse) or not.

    So the USCG built ground stations that would receive GPS signals, calculate the SA error, and broadcast a fixed signal. That was called Differential GPS, or DGPS. Boaters could buy special DGPS receivers for years, which were as accurate as GPS without the SA error.

    Eventually the military was convinced to do away with SA entirely so DGPS was retired. It was only after that happened that GPS became globally useful for car, hiking, etc. navigation.