36 comments

  • numpad0 3 hours ago
    I've heard that some Subaru models have 3 clocks in the view of the driver, all on the CAN bus, one being the nav and another being a remote display for the nav, and one that's just there, of which none sync to each others. I've looked up how it happened, and discovered that to just to add insult to injury, at least one uses a uC that has RTC feature but no XTAL pin for 32.768kHz or one of any sane base 2 divisions and uses CPU clock of 15MHz or something for it, so it just drifts away.

    I don't understand how Subaru stays in the business. Just how. It's a 4 digit time. Just broadcast it on CAN. Why not.

    Also: a lot of these older, completely rectangular sat nav units actually follow what is colloqially known as "2DIN" standards. (cheap import Amazon)Aftermarket units are available and those can be swapped in with just a bit of work. That's what most people do when they have issues with the stock unit installed for their markets.

    • flanz_10 8 minutes ago
      > I don't understand how Subaru stays in the business. Just how. It's a 4 digit time. Just broadcast it on CAN. Why not.

      they sell SKUs with no nav and no remote display for the nav. and they still need a clock.

    • ubermonkey 1 minute ago
      >I don't understand how Subaru stays in the business. Just how. It's a 4 digit time.

      Uh, presumably you understand that the core value proposition of a car does not hinge on timekeeping, right?

      Subarus are famously long-lived and reliable. That's how they stay in business.

    • ManuelKiessling 1 hour ago
      My smart fortwo has two clocks, one on the radio, one in the driver’s dashboard;

      Both go wrong over time, but both in two different directions, so the trick is to calculate the „average“ between both, and you end up with roughly the correct time.

      • Gravityloss 29 minutes ago
        We have this in the kitchen with the stove and the microwave, both from this decade! Apparently still a very hard problem.
      • ErroneousBosh 1 hour ago
        My '97 Range Rover has an analogue clock with a quartz-controlled movement, and a button to set the time.

        It gains anything up to an hour a day, particularly when my six-year-old is helping me clean the car and he pushes the button to watch the hands go round really fast.

        It's fine. Time is time, we get there when we get there.

    • giancarlostoro 58 minutes ago
      > I don't understand how Subaru stays in the business. Just how.

      Not sure if relevant, but Toyota has been buying parts of Subaru over the years, in 2020 ~ they have roughly 20% of Subaru. I'm not sure if its one of those "Microsoft investing into Apple" or "Intel investing into AMD" type of moments (which tbh, I wonder if Nvidia should be trying to invest in Intel or AMD since they're doing so freaking well its horrifying).

    • loeg 2 hours ago
      And their engines have struggled with gasket issues and oil consumption for a long time. People here love the AWD, though (my state enshrines AWD as a special class in law, artificially driving some demand).
      • clickety_clack 2 hours ago
        That makes sense. AWD handling is so much better in winter conditions that I feel it has to make it less likely to crash.
        • eldaisfish 20 minutes ago
          AWD is great at getting a vehicle moving, so long as you aren’t planning on stopping.

          Misconceptions like this are why people are lulled into a false sense of security.

        • loeg 37 minutes ago
          Winter / 3MPSF tires are a much bigger factor, but are not similarly enshrined in state law. And all vehicles have all-wheel braking.
      • numpad0 2 hours ago
        Of the EJ20 just to keep it easy to play with the blocks without needing a modified type certs right? None of my business but they seem to be a bit unserious somewhat within bounds of a car company.
      • rogerrogerr 2 hours ago
        What benefits do you get from having an AWD car in your state? Tax treatment?
        • loeg 36 minutes ago
          You can travel mountain passes in the winter without putting on chains (most of the time). Regardless of whether you're running winter/snow tires.
        • galleywest200 2 hours ago
          In western Washington State everything is on a hill and it feels as if the road is always wet all the time due to rain. Subaru is the most popular car brand in the whole state because it handles these conditions well.
          • hinkley 1 hour ago
            Wet all the time isn’t a serious loss of traction. Wet after a dry spell is, and everyone there forgets it every time. You will have delays on the highways due to wrecks.

            Nobody has the slightest clue how to deal with ice.

            • loeg 9 minutes ago
              Wet is ~40-50% reduction in traction on asphalt, and it's even worse for paint. That seems pretty serious. (Of course, surface oils can be even worse.)
            • zrm 1 hour ago
              Wet is a significant loss of traction, it's just that wet after a dry spell is even worse.

              I'm from the Northeast but happened to be in Seattle on a day when it snowed. Every road was a hill and every hill was full of sideways cars.

              • psunavy03 47 minutes ago
                People who make fun of greater Seattle for freaking out over snow generally don't understand just how extreme the topography is out here, even downtown and on the highways. It's not Ohio or the Northeast with at most gently rolling hills. It's snow PLUS ridiculously steep terrain.
                • Klonoar 17 minutes ago
                  I live in Seattle - on top of one of the largest hills in the city - and think you all are overreacting.

                  Past two winters I was in RWD too. Just exercise some throttle control and get proper tires.

                  (Snow I’m willing to acknowledge is trickier, but modern cars in wet roads shouldn’t be hampering any of you…)

                  • loeg 8 minutes ago
                    Tires are the big thing. The vast, vast majority of Seattlites aren't swapping out for a winter tires set in winter, and they aren't running a 3PMSF-rated all-season / four-season / all-weather tire, either.
        • stronglikedan 1 hour ago
          Just the benefit of driving AWD is enough for me. It's hard to go back...
          • AdrianB1 8 minutes ago
            It is easy. I drove for several years a car with permanent AWD (Audi A6 Quattro), then moved to one that can switch between front drive and AWD. I don't remember the last time I switched to AWD (mileage is better if I leave it on front drive only).
        • 1_1xdev1 2 hours ago
          With AWD, the tire requirements when it’s snowing in the mountains are more relaxed compared to 2wd vehicles.
          • loeg 36 minutes ago
            Just relaxed chain requirements in Washington.
          • hinkley 1 hour ago
            However every time one of your tires goes bad you have to replace all four.
        • internetter 2 hours ago
          This is a niche problem but I live in Colorado
        • kridsdale1 2 hours ago
          Mountains.
    • emeril 3 hours ago
      subaru infotainment is junk but they are a good deal for a safe car
      • tshaddox 3 hours ago
        I've heard that the redesigned 2026 Outback has a much nicer interior. Lots of physical buttons and supposedly more stable infotainment software.

        We've been pretty happy with our 2020 Outback so far (bought it just before the chip shortage). My only complaint is the stability of the infotainment software. The big portrait screen is actually quite nice, and with CarPlay I don't really care about the rest of UI and software. Except that the stupid thing just crashes all the time.

        • emeril 2 hours ago
          yeah, I've heard that too - I have a new forester - it's def slow/finicky

          maybe I'll get a outback instead next time, they are kind of the same to me though the hybrid on the forester I have def makes it a more pleasant less CVT'y ride...

          • tshaddox 2 hours ago
            I'm hoping they bring the new Outback design (both exterior and interior) to the Ascent. The 2027 Ascent is already out and unfortunately it's the same old styling and infotainment.
      • unfocused 1 hour ago
        I can confirm. My Subaru 2023 forester's infotainment unit got replaced after 1.5 years due to it randomly crashing, and Carplay being unstable. On a long road trip, if you go to get gas, unplug your phone, and try to replug, just wouldn't connect. Even rebooting it. Nothing. Also had my 2 front speakers stop working, which mean handsfree didn't work since phone calls are routed to front speakers only. Had to unplug the car battery, wait, and then the speakers worked.

        Does anyone know why the mini display on the top, lags so much when changing music tracks or even Radio stations? It even sometimes doesn't update the radio station, and just mixes up data from 2 different stations. Replacing the infotainment unit didn't fix that or the lag. It's like purposely designed to be annoying.

        • numpad0 10 minutes ago
          That small display on top of aircon vents is called Multi Function Display and it's its own thing, IIRC getting information from CAN bus from supoorted nav units. If that one is dropping messages, maybe it's a grounding or a harness issue?
      • lotsofpulp 13 minutes ago
        I will never buy Subaru because their infotainment garbage had a phantom power draw causing dead batteries left and right. Subaru refused to acknowledge it, so I spent $1k out of pocket to get it fixed to have a usable car.

        Then I got a notice in the mail that Subaru agreed to replace and compensate people for the phantom power draw issue, except I wouldn’t be eligible because I couldn’t prove it since I already fixed my issue…even though Subaru knew all the VINs with the problem.

        https://www.subarubatterysettlement.com/

        Plus I have had to replace bearings and control arms within 50k miles…which I expect better on even American brand cars much less Japanese.

      • ubermonkey 1 minute ago
        I mean, who cares about $automaker's infotainment if Carplay or AndroidAuto is available?
      • MattSayar 3 hours ago
        I also only use Android Auto, and plugging my phone in updates all the clocks automatically
      • john_strinlai 1 hour ago
        indeed, i have had several subarus in my life from a bone stock 98 impreza RS through to the newest STI, and while i love them and will probably never buy another brand, the infotainment (and speakers) absolutely suck in all of them.
  • jerlam 4 hours ago
    I had a luxury car from 2001 where the time could not be manually changed, only set to specific time zones. Of course, all the time zone rules had long diverged from its rule set, and it had to be changed four times a year to show the correct time.

    This car also inexplicably forced you to manually choose a country, and then a time zone, despite having a GPS that already knew exactly where you were and already had chosen a previous time zone.

    Carplay is nice but I would have settled for a non-luxury "clock set" button.

    • wvenable 9 minutes ago
      I live in a region that changed time zones just 2 days ago and my brand new 6-month old car now as an incorrect rule set and presents the wrong time when synced with GPS.

      It has no over-the-air update capability so it seems like this sync-with-GPS feature is now broken for me unless the manufacturer puts out an update to be done at the dealership.

    • bobmcnamara 4 hours ago
      My 2025 Toyota has two clocks, one from Toyota, one from Android auto.

      The Toyota one requires selling your driving data to insurance companies.to update the tzoffset based on location.

      And so two clocks on the dashboard are off this week until I can remember where the dst adjustment is in the settings.

      • Uncle_Brumpus 3 hours ago
        My 2019 Subaru has a red 7-segment LED clock below the touchscreen that has 2 physical buttons right there that change the hour and minute. It's a luxury I don't think I'll soon take for granted. I changed my battery recently (the original OEM battery finally got too tired), so I've set my clock twice in the last week, taking about 10 seconds and 1/2 second to accomplish respectively.
      • onaclov2000 3 hours ago
        I can't wait until folks start pulling firmware out of head units, using AI to remove the crap, and putting it back in (akin to the TV revolution happening now)
        • dotancohen 1 hour ago
          Open AI put a stop to the TV hacking. I can not wait until memory gets cheap again and we could run large models _comfortably_ at home.
          • ryandrake 1 hour ago
            Yes, I don't expect my software tools to selectively fail when they determine that my command puts another company's business model at risk.
    • eightysixfour 3 hours ago
      > Carplay is nice but I would have settled for a non-luxury "clock set" button.

      The clock set button is obviously the right solution, but this is actually why I demand CarPlay on any infotainment system in a car. I don't trust the manufacturers will keep it up to date, but I know my phone software will be updated/updateable/replaceable.

    • antod 1 hour ago
      (in NZ) I have a 2005 import from Japan with time set by GPS, but apparently no way of changing the time zone away from Japan. The navigation still thinks I'm in Japan too but randomly flying around at high speeds too - even the compass calibration is way off. I too would rather have a manual clock set.
    • someguyiguess 4 hours ago
      Honestly I’ll just wear a watch.
      • prmoustache 3 hours ago
        I would have taped a $5 casio watch clone on the dashboard were the clock is supposed to be shown.
    • functionmouse 4 hours ago
      Could be planned obsolescence.
  • tom1337890 4 hours ago
    Awesome write up. Love it. And good thing you documented it, since in half a year you'll need it again.

    My takeaway: You should have just gotten the SD card and trusted the previous owner. Sometimes "simple users" do know. ^^

    • landgenoot 0 minutes ago
      Just add a cronjob based on tzdata?
    • xx_ns 4 hours ago
      Yep. I didn't get into it in the article, but in reality the previous owner had already (accidentally) thrown the SD card in the trash, and was pretty much asking me if they want me for them to go digging through their trash to find it, and I told them not to worry about it.
      • Barbing 4 hours ago
        “No worries, I’ll hit HN’s front page instead” - much more fun!
      • lisper 3 hours ago
        Why did the previous owner ever remove the card in the first place if they knew it broke things?
        • gambiting 3 hours ago
          Because if OP didn't want the card, then the card could be sold on ebay for 60 euros.
      • tom1337890 2 hours ago
        That's kind of you :-)
      • bornfreddy 4 hours ago
        Nice writeup. But IIUC you can change it so that it automatically updates the time every 6 months?
    • bgun 4 hours ago
      I’m a little confused by the description of that interaction - why wouldn’t you take the SD card? Did they want to charge extra for it? Seems like even a 10 year old map (plus apparently other functionality) is something you’d want.

      In any case, glad it took you on the wild goose chase that led to the write up!

    • darknavi 4 hours ago
      > And good thing you documented it, since in half a year you'll need it again.

      Man this is too real for personal projects. I really need to write down my findings and thoughts more for future me.

      • drivers99 4 hours ago
        I started using an "engineering notebook" for things like that. They are called other things in other lines of work or school (lab notebook, captain's log, ...). In an actual engineering notebook, you would use a sewn binding where you can't add or remove pages, the pages are numbered, you have an index in the front, entries are made in strictly chronological order, you'd have someone else witness and sign pages, draw a diagonal line across empty areas so you can't remove things, only cross things out with a single line, etc. All that because you might need to prove you invented something and other legal CYA reasons. Most of these requirements, you don't need for personal projects, though. But the things that are useful: keeping track of projects, what settings you've tried, what the results were, and so on. That way you don't have to reproduce it from scratch again later. "What settings did I need use to create the gerber files in kicad for manufacturing? How did I set ___ in the oscilloscope? What parts did I use to make that thing? What things did I wish I had checked last time? Where did I put those files?" You can also print things out and tape them in for reference.
        • EvanAnderson 3 hours ago
          I love the ergonomics of hard bound engineering notebooks. The cost is more than I'm willing to pay for the pedestrian kind of notes I take, though.

          I got a few of them, partially-used, from a canceled project and I really enjoyed using and carrying them.

          • drivers99 2 hours ago
            I just use composition notebooks which are like $1-$5 depending on the quality, store, sales, etc. That's also what we used as a lab notebook in chemistry class when I was in high school, which follows a similar discipline, so to me it's fitting.
      • warkdarrior 3 hours ago
        MEMORY.md is your friend.
        • Forgeties79 3 hours ago
          I’d rather read my own internal wiki tbh
    • mikestew 4 hours ago
      That’s the part I don’t get: just take the damned card, you never know. Worst case: hey, free SD card!
  • RajT88 4 hours ago
    Add to falsehoods programmers believe about time:

    It can be changed without the SD card in the car radio.

    • warkdarrior 3 hours ago
      The whole article is ludicrous. Why do you even need a car with an SD card slot in order to change the time? I reset all of my clocks this weekend and I don't even have a car.
      • ivanjermakov 3 hours ago
        This question was certainly asked during a meeting 30 years ago and the answer was "don't worry about it".
      • leni536 1 hour ago
        Well, they needed a car to change the time in "Back to the future".
      • mschuster91 3 hours ago
        > Why do you even need a car with an SD card slot in order to change the time?

        The idea was that time came from GPS and you had a SD card with the update files for the maps and the current tzdata information. Timezones worldwide change ridiculously often and tying that together with the regular map updates makes sense.

        Remember these things are from an era where smartphones were barely a thing and so was mobile phone connectivity in cars.

  • easymodex 20 minutes ago
    This is really hillarious to me since I have the exact same problem in my Renault Scenic, there's just no way to change it. But half of the year it's correct, the other half I just automatically deduct 1 hour. It's one of those problems that are on the to do list but realistically I'm never gonna spend that much time on it. Not really a good engineer answer but oh well. Nice writeup!
  • strenholme 3 hours ago
    My car came with a cheap low-quality aftermarket combination car stereo and GPS. It would only play music from discs (no USB support), didn’t even support variable bitrate MP3s, and the GPS didn’t know the car’s location half the time.

    I finally replaced the head unit with a plastic bracket and a standard old school in-dash stereo system. Much nicer setup.

    It’s the cars which can’t have their head unit replaced with a simple stereo which worry me.

    • RulerOf 3 hours ago
      > It’s the cars which can’t have their head unit replaced with a simple stereo which worry me.

      I agree. There's a lot of room for innovation, consumer choice, and competition that was previously guaranteed to be available in those one or two DIN units of space.

      I haven't seen them present in any new car I've looked at in nearly ten years, but they were in every car I saw from the 50 years prior.

    • et-al 3 hours ago
      Denso head units for Toyotas can play MP3s, but the order of the files is when when they were copied to the SD drive. And you can't sort them any other way.
      • mixmastamyk 35 minutes ago
        You can move files off and back on the drive and they’ll be in alphabetical order. If FAT, fatsort can do it afterwards.
        • et-al 27 minutes ago
          Yes, I can move the files, but it's also ridiculous in the 2020s that I have to resort to doing this workaround instead of the software reading ID3 metadata and sorting by one of the well-known fields.

          Thanks for the tip on fatsort, it does save me a bit of trouble.

    • guywithahat 3 hours ago
      The counter argument to that is well designed modern cars have great info-tainment systems which get regular updates. My Tesla gets regular software updates, has upgradable hardware, and won't be subject to these kinds of issues for decades. Old cars encouraged exchanging and needed aftermarket parts because they didn't care or try, so the products were low-quality and often failed.
      • Rebelgecko 2 hours ago
        Legacy automakers are still using the "ship it and forget it" approach. If I want my 2023 Hyundai to have the same features as a 2025 (manual battery preconditioning, Google Maps directions on HUD, wireless Android Auto, etc), I need to root the head unit and install a bunch of vibe coded packages from randos on GitHub.

        Although to be fair the vibecoded packages are probably higher quality than what Hyundai would've shipped.

        • fullstop 59 minutes ago
          ioniq 5? The 2023 didn't have manual battery preconditioning?
      • jerlam 2 hours ago
        > My Tesla gets regular software updates, has upgradable hardware, and won't be subject to these kinds of issues for decades.

        Teslas from four years ago with Intel Atom processors and HW3 are already getting different and lesser updates than new Teslas, without any hardware upgrade plan in place.

        A Tesla you buy right now is running HW4 which is inferior to current Cybercabs and HW5 has already been announced.

        • dotancohen 1 hour ago
          Every new car on the planet has better hardware than the previous generation car.

          Except for maybe the '58 Thunderbird, but that was rectified in '61 in my opinion.

      • nullc 2 hours ago
        > well designed modern cars have great info-tainment systems which get regular updates. My Tesla gets regular software updates

        And tracks you everwhere you go, resulting in that data being available to hackers, marketers, and any sleazeball that wants to extort you by suing you.

        Not unique to tesla, of course, but a property of all those 'well designed modern cars'.

  • loufe 51 minutes ago
    I've been thinking about this for a 2016 Toyota in the family which has a quirky but decent enough idea for the main screen where a local DB file is consulted and a saved picture of the currently playing artist is displayed.

    Sounds great but there are some hilarious examples where the fuzzing of the name (best guess, I figure in case the name is slightly wrongly typed - mp3 era) is far too loose. "Bayonne" is showing a picture of Beyoncé and "Steve Lacy" is showing a bald white guy. It has become one of those things in life where I get a bit excited to see who a brand new artist will get as the matched image, reminds me of childhood, honestly.

    I figure with the game decompilation news I'm seeing the reverse engineering of the firmware (or at least the DB format) would not be a significant challenge, and it would mix in some fun other tasks like compiling (and signing?) a new DB with tons of images and names, and then figuring out how to avoid bricking a vehicles computer while doing so. But... like I assume many others here... I've got enough projects on the go right now so maybe in a few months.

  • somehnguy 4 hours ago
    My 2014 vehicle stopped updating it's time automatically a few years ago. I think some cellular technology was phased out or perhaps the cellular contract GM had for vehicle connectivity expired.

    Either way I just manually set the time twice a year now - I guess I'm thankful it still has that option.

    When I was playing around with the radio in my girlfriends vehicle there was no option to set manually on the clock screen. Seems like a pretty shortsighted move to not allow that.

    • justonceokay 35 minutes ago
      My 2014 Mazda 3 has two buttons directly under the clock: “HH” and “mm”. To reset the clock during spring DST I have to press “HH” once. In fall I have to press it 23 times. The clock is so accurate I think I realistically only hit the “mm” button when the battery dies.

      Funny to see how even in 2014 things were diverging so greatly

    • gopalv 4 hours ago
      > the cellular contract GM had for vehicle connectivity expired

      2022, I got a letter saying that my car's crash response SOS system will stop working because FCC is retiring the 3G spectrum it is using.

      The car clock however is synced to the GPS instead.

      If GM used NTP instead of GPS, then it makes sense that it stopped working arbitrarily around 2022.

    • lloeki 34 minutes ago
      Your tech expectation may be way too modern, could be some terrestrial radio clock being phased out. Back then some AM/FM alarm clocks would sync time over low freq radio. For FM, RDS can do it too.
    • nradov 3 hours ago
      Older versions of the GM OnStar hardware used 2G cellular radios and carriers have decommissioned those networks. Adapters are available for some vehicles to use newer networks.

      https://www.onstar.com/support/faq/2g-network-sunset

      • autoexec 3 hours ago
        Considering that OnStar spies on you even if you don't subscribe to the service it's much better to just leave it broken, or even to actively disconnect it in newer vesicles.
    • Symbiote 3 hours ago
      In 2019 there was a GPS week number rollover, another possible cause.

      https://en.wikipedia.org/wiki/GPS_week_number_rollover

    • alerighi 2 hours ago
      It seems absurd to me that cars needs a cellular connection to automatically set time, meanwhile 10$ clocks can get the time correctly from the radio signal that are broadcasted. More insulting the fact that the car itself has an FM and also an AM tuner that are capable of receiving time signal and decoding them while the radio is not in use. And that modern cars that use digital radio (DAB) have a standard to get the time. Come on, car infotainment is so outdated...
  • aloukissas 14 minutes ago
    My buddy did something similar to his 2018 Mazda 3 to switch the AC controls from F to C.
  • runnr_az 4 hours ago
    As an Arizona resident, my recent Honda CRV's clock is off by an hour for half the year. Since usually the carplay display overrides the clock, it's no big deal, but it cracks me up that, despite being a professional programmer, I have yet to figure out how to set it correctly
    • jerf 4 hours ago
      The difficulty of setting a VCR's clock was a meme in the 1990s, and I can attest, justifiably so.

      But at least it was possible. The clock setting being impossible without a proprietary and easily lost or destroyed SD card is pretty good, but we can do better. It could be just impossible to fix a wrong clock. Truly that would be the apotheosis of user unfriendly design.

      • Twirrim 4 hours ago
        My very technical and hands on father used to have us set the VCR clock, the controls were in a tiny compartment under a flap that required either small fingers, or very careful manipulation with the point of a protractor or something.

        We went from difficult to manipulate buttons through to multi-function buttons where controls get hidden through some incomprehensible maze of menu options, to now where it sometimes feels lucky if you even get an option to manually set the time at all.

      • 220hertz 4 hours ago
        I'm reminded of an old commercial depicting kids taunting another kid by asking "What time is it at Billy's house? 12 O'Clock! 12 O'Clock! 12 O'Clock!" Might have been a Blockbuster commercial? I can't remember.
        • iamjackg 2 hours ago
          Oh man, this reminds me of an episode of a show I watched when I was a kid in the 90s, where the running joke was all the characters, at different points, saying something like "I tried setting up the VCR to record it, but every time I press the button the number 12:00 starts flashing on the screen and I panic." I haven't been able to find it again. I think it was https://en.wikipedia.org/wiki/Mother_Goose_and_Grimm_(TV_ser...
    • bookofjoe 4 hours ago
      In 1974 when I was an medical intern at Los Angeles County-University of Southern California Hospital, ALL the round analog wall clocks with hands in all 26 operating rooms were correct six months a year: there was NO provision for automatically advancing/moving them back when DST started/ended, nor did anyone do it manually.
      • yardie 3 hours ago
        I was told by our school electrician that long ago the clocks were adjusted by the power company. So around 2am DST they would either send power at 59Hz* to fall back or 61Hz* to spring forward. This was from the era when power grids were separate and analog. With newer national grid-tie it might not even be possible to do now.
        • skipkey 3 hours ago
          I don’t know about that, but I was told by someone who worked at a power generation plant in the 1970s that they had a clock in the plant, that they would compare to the time broadcast on the radio frequency that carried the official time, and any time it diverged they would slightly adjust the frequency of the alternating current until it matched.
          • yardie 3 hours ago
            I was a kid but I do know the clocks in my elementary, middle, and high school were accurate. Near end of day, we would impatiently stare at the clock waiting for the release bell. Being a public school, the clocks were bolted securely to the wall. Being little shits, students would probably steal them if they could, LOL. So how did they keep 100s of clocks on time? I asked and was told by the school maintenance that it was done through power.
        • Majromax 1 hour ago
          > I was told by our school electrician that long ago the clocks were adjusted by the power company. So around 2am DST they would either send power at 59Hz* to fall back or 61Hz* to spring forward. This was from the era when power grids were separate and analog.

          That wouldn't have worked.

          Grid-tied synchronous clocks (https://en.wikipedia.org/wiki/Electric_clock) were once ubiquitous and did derive their timekeeping stability from the grid frequency, but that is only suitable for keeping time once set. It works because electric grids are frequency-controlled and stabilized, where deviations from the reference frequency are corrected over long intervals.

          In principle you could send power at 59 or 61Hz to adjust these clocks, but there are two problems:

          1. The grid frequency isn't arbitrary, it's also directly coupled to the rotary inertia of every turbine that powers the grid. This is why power fluctuations cause frequency changes: temporary oversupply or undersupply causes these turbines to slow down or speed up respectively, using their inertia as power storage. Potentially screwing up every other piece of mechanical equipment tied to the grid for the sake of clock changes is... a poor optimization.

          2. A one-Hertz difference isn't enough to change the clocks in a timely way. To change time by an hour you need to gain or lose 3600 * 60 = 216k cycles, but a 1Hz change gains or loses one cycle per second. It'd take about 2.5 days to complete a one-hour change via this mechanism.

      • jandrese 2 hours ago
        I remember in my elementary school the clocks were all synchronized to a system somewhere, presumably in the head office. The day after going back to school after a DST change the clocks would all be off by an hour and sometime in that morning they would all suddenly freeze, then fast forward or rewind an hour and then restart. In retrospect it is amusing that whomever was in charge of updating the clocks didn't do it when they first got in but waited until the school day had started.
      • EvanAnderson 4 hours ago
        It's crazy they didn't have a centralized clock system in a facility like that. What a thing to scrimp on.
        • jandrese 2 hours ago
          What are the odds they did have a centralized system for setting the clocks, but nobody knew how to operate it or cared enough to find out? Maybe someone set a password and then lost it. And of course if you have a centralized system it means you can't manually fix the individual clocks.
        • bookofjoe 3 hours ago
          I'd laugh whenever I looked up and saw the wrong time....
      • ButlerianJihad 3 hours ago
        I worked in a Network Operations Center in the early 1990s, and there was a large projection display with four other monitors around it. Across the top were four round analog clocks, representing the time zones of the United States. I was one of four operators, all in our 20s.

        So, Daylight Savings Time ended, and the early-morning operator had all the clocks set by the time I arrived, and the third operator came in, looked at them, and said "Great! So, did you take all four of them down and adjust the time individually?" "Yeah" "Didn't think about taking one off the end, adjusting it, and moving the others down the row?" *facepalm*

    • lloeki 27 minutes ago
      Being a professional programmer, set it to UTC once and be done with it!
  • superjan 3 hours ago
    A design rule for the display of any appliance with a clock: It must be possible to remove or hide the clock. I don’t need 10 devices to keep track of time for me.
    • JoshTriplett 3 hours ago
      Yes, please. I don't want a clock on my microwave, or my oven. If I'm not interacting with it, it should produce zero light.

      (Some people use oven features that involve knowing an absolute time, such as "turn on at this time". That seems to be the uncommon case, and meanwhile everyone has to deal with a clock that's rarely right.)

      • fullstop 54 minutes ago
        My microwave defaults to no clock after a power outage. I prefer it that way.

        I used to have a range, then microwave, then toaster oven, then coffee maker, all with different times. I tried so hard to get them in sync, but it was just not possible. Plus, the coffee maker clock would drift over time. Since that point in my life the microwave, toaster oven, and coffee maker have been replaced and only the microwave has an optional clock.

        Oddly enough, the newer appliances are all higher quality than the ones they replaced. I guess clocks are added to things to give them more perceived value.

      • jandrese 2 hours ago
        Eh, if you only have a clock on only the microwave or oven then you lose access to the current time when you're cooking something or convert it over to timer mode. Having some redundancy isn't a bad thing in this instance.

        Or simply have a dedicated clock in there and turn off the display on all of the appliances.

        • JoshTriplett 1 hour ago
          There should be two kinds of devices in my home: those allowed to connect to the Internet and keep their time up to date, and those that are not allowed to care what time it is. My microwave and my oven are in the latter category.
      • lifestyleguru 2 hours ago
        > such as "turn on at this time". That seems to be the uncommon case

        Indeed. "Please create fire hazard exactly at this hour when I'll not have time to do it personally".

        • delecti 38 minutes ago
          Many Jewish people use the feature while home. There are prohibitions on lighting fire on the sabbath, which has been interpreted more broadly as a prohibition on "turning stuff on". That's why you can set your oven to be on all day on Saturdays, for example, but they are usually home while it's happening. You can't turn the oven on, but you can use it while it's on. Similarly, some elevators are configured to stop on every floor on the way up and down on Saturdays.
    • lifestyleguru 3 hours ago
      Best they can do is blinking "12:00". Actually I encountered a kitchen appliance doing almost the opposite, after power off/on it didn't function before confirming any time.
      • jonathanlydall 0 minutes ago
        My 4 year old Siemens oven is like this, as is the one (can’t remember the brand) in the previous house we rented for a short bit.

        I wonder if it’s a kind of child safety thing. It’s possible on my current oven to enable a child lock by holding the clock button for 5 seconds, preventing the turning of the knobs from having any effect.

        After a power failure the oven similarly will not react to the knobs being turned until the clock button is pressed, but a mere second or so is good enough.

      • fullstop 52 minutes ago
        My microwave, a Panasonic, will show " : " after a power outage. It's perfect.
    • blacksmith_tb 3 hours ago
      Amen to that, I have a pair of built-in IKEAs, a microwave and convection oven, both with clocks when they're idle. But of course they're separate devices so they drift separately, which is obnoxious-looking. Happily the microwave did have a hidden setting to just display - - - - instead of the clock (though for no apparent reason the convection oven does not have that option, sigh).
  • hypfer 3 hours ago
    For certain model years of nissan, there's this, btw

    https://github.com/ea/bosch_headunit_root

    If anyone feels like using that access to throw some tokens at various systems.

  • jdlyga 3 hours ago
    I never understood why car companies don't put more effort and resources into their MMI systems. Audi is a big offender. I've never seen a more thoughtfully designed car with an MMI interface that's more frustrating and buggy.
    • joezydeco 3 hours ago
      There are two paths and both don't work anymore.

      First is to bring the hardware and software design in-house. Except auto companies don't do well at software, they're used to letting OEM vendors write the engine control firmware etc etc. There's also the problem of the very long design cycles in car manufacturing. The new car platform being built today started its design four to five years ago. And that's when the hardware was locked down.

      Volvo's platform was so old at launch that they threw in the towel and are now offering to upgrade your hardware if you complain hard enough.

      The other choice is to shop it all out to a consulting firm or OEM vendor. Then you have cultural conflicts between the car maker and the programmers, communication overhead, choice of hardware conflicts, etc. And you know it's going to be shopped out to the cheapest bidder. And you're still at the mercy of launching with hardware that's way older than the smartphone in the driver's pocket.

      • bluGill 1 hour ago
        Auto companies almost all do their own engines. They may trade but they make their own. That includes software.

        TDD was an invention of Chrysler.

    • jbm 3 hours ago
      Even companies with betterish interfaces screw this up.

      My Model 3 is showing the wrong time and this requires an OS update to fix.

      Suffice to say I would prefer an option to update it myself.

      https://driveteslacanada.ca/news/tesla-fixes-bc-clock-bug-up...

    • Perz1val 3 hours ago
      Isn't the same true for all embedded? They seem to have half assing UX in their job description
      • ryandrake 1 hour ago
        Almost all hardware companies don't understand or care about software at all. They see "software" as just another line item on the BOM, like a screw or a gasket. You source it from the cheapest supplier and then attach it to the product somewhere on the assembly line. The idea that software is the interface to the user, a signal of quality, part of product differentiation, an ecosystem in which future products live... none of this even remotely occurs to most hardware companies, especially car manufacturers.
    • numpad0 3 hours ago
      Isn't it because the nav feature is market specific? People generally don't seem to like nav software brought in from different continents, across the planet.
      • lefra 1 hour ago
        I'm european, recently went to Korea. The nav system was almost perfect, only complaint I have is that it signalled every single speed bump (I can see them, thanks). There probably was a setting somewhere to tell it not to, but I didn't care enough to try to find it.
  • zodwick 3 hours ago
    The revolution against shitty locked down software has begun and I LOVE IT
    • otterley 3 hours ago
      A blog post and the commiseration of HN randos does not a revolution make.
    • encom 3 hours ago
      Has it? Feels like we're just getting more of it all the time.

      "Hold on babe, the christmas lights have to finish installing a firmware update", is a real sentence that actual people are saying in 2026.

  • yitchelle 1 hour ago
    Apt time to share this video about jailbreaking a car's navigation system to get its PIN to unlock it.

    https://www.youtube.com/watch?v=oC6AiLqjtRg

  • cogogo 2 hours ago
    I got a new samsung smart tv in April and never connected it to the internet. Just noticed (likely because if the DST change) that the date and time was all wrong when it turns on. Could not unnotice it. I was very pleasantly surprised I could manually set it and no internet was required. I expected to be annoyed at it forever or to go down a rabbit hole like this and fail.
  • gregsadetsky 5 hours ago
    I was just wondering the same thing for a 2013 Honda Civic - has the screen's (the "head unit"?) firmware been fully dumped and reverse engineered?

    How realistic would it be to run fully custom firmware there, and even communicate over usb - for example, if I had a pi running in the car, and it used the usb connection to show things on the built-in display?

    • EvanAnderson 4 hours ago
      I'd love to pwn the head unit in my 2014 Honda CR-V just so I can stop it from sending a "Play" command every time a phone associates with the Bluetooth and the audio system was left "on".
      • kowbell 3 hours ago
        I also have a 2014 CR-V and I hate this too. But even moreso, I hate that there isn't a play/pause button at all. If I need to stop audio (e.g. pulling up to a drivethru, or starting a conversation), I gotta hit the phone. Heaven forbid I'm playing a CD, nothing I can do at that point.

        Putting up a bug bounty of "ordering you a pizza" if anyone tackles this!

        • jandrese 2 hours ago
          Had a Chevy that was extremely obnoxious about this. If it was playing over USB it absolutely would not allow it to stop. Hitting pause on the phone would have the car immediately hit play to restart it.
        • EvanAnderson 3 hours ago
          I get pause (for Bluetooth playback, at least) by pushing the volume encoder knob. That works well for me.
    • rockostrich 4 hours ago
      It's probably easier to just buy an aftermarket head unit. The only thing you'll need to confirm is that it supports features you care about e.g. steering wheel controls.
    • rithdmc 4 hours ago
      Probably more difficult than hijacking the display with the pi. But that's just a vibe.
  • felineflock 2 hours ago
  • vessenes 4 hours ago
    Okay, this was gratifying to read, but ... can't you wedge CarPlay onto this thing? I'd want a victory lap with root doing at least something. Bad apple on car boot, there's lots of options here!
    • xx_ns 3 hours ago
      Yeah, I'll keep working on this to get it to do more stuff that's at least a little bit more useful, if not just a better UI that isn't 90% a useless "No maps found" screen. It's more complicated than it might initially seem because they actually have a kernel module blocking me from mounting non-signed partitions as exec, so I'll need to work around that.

      I'll probably post a follow up if I get anywhere with this!

  • whycome 5 hours ago
    Pretty awesome write up to explain their journey in it all.

    I suspect a bunch of car head units will face new problems in the spring when many Canadian provinces will no longer change their clocks. The units won't get updated DST rules.

    • Niksko 3 hours ago
      Happened to my Mazda the other day. Thankfully it supports just setting the timezone and dst flag manually.
    • monegator 4 hours ago
      which is mind boggling.

      my skoda simply has an entry in the menu: DST? which puts the clock one hour ahead or behind.

      This posts remind me that when i will be in the market for a new van i will have to decide to get the trafic or the vivaro, solely on the head unit they use (renault ones have had incredibly stupid design decisions for years, on ergonomics alone, even more in firmware)

      • settsu 3 hours ago
        Yep, in my mind this is one of the hallmarks of a well-designed digital desk clock: a 2-position hardware switch for DST on/off.
    • iclelland 4 hours ago
      That's this fall - happened a couple of days ago.
  • js2 1 hour ago
    Bravo, but:

    > When I bought the car, the previous owner asked me whether I wanted a "navigation map SD card" with it.

    Why would they even ask?

    > Since the maps on the SD card were apparently very out of date and didn't function properly, I decided I didn't need it and the previous owner tossed it.

    WTF? My 2016 Mazda has an out-of-date SD card too. I removed it because it slightly speeds up how fast the system boots without it, but it's in the glove box for any future owner when I sell the car. I just can't understand tossing it. It's not like it takes up any room.

    (My Mazda also sets its time via GPS, but I can get to the timezone offset and DST checkbox regardless of the presence of the SD card.)

    • xx_ns 26 minutes ago
      They basically asked me if I want them to go digging through their trash because they had accidentally thrown it out just shortly before handing the car over. I said that it's no worries and I'll figure it out. Just didn't expect that this would be the way I'd do it.
  • maelito 3 hours ago
    I wonder how many systems have a good web browser embedded. Last time it was tried on a tesla, it could barely render a maplibre map.

    The Web is a universal platform very capable in 2026.

  • yowayb 4 hours ago
    not quite as difficult, but reminds me of a fix I found on reddit for Subaru Outback parasitic drain: https://www.reddit.com/r/subaru/comments/1evozzf/dead_batter...
  • 1970-01-01 3 hours ago
    Usually you can just get a modern OBDII scanner and set it via the diagnostics or hot functions.
  • geephroh 4 hours ago
    Love it! Slightly more elegant than my solution: a piece of electrical tape over the clock.
  • speedgoose 4 hours ago
    The Renault Latitude is actually Samsung car right?
  • encom 3 hours ago
    I wish someone would jailbreak the Nissan Leaf (MY2018) head unit. Every time I turn on the car, it shows a EULA asking if Nissan can please collect every detail of my car at all times and sell it to whoever asks.

    Every. Time.

    Even if I beat my head with hammers to think like a lawyer, I can't imagine how it would be necessary to ask constantly. Doesn't matter if I accept or decline, it still asks again.

    • properbrew 1 hour ago
      I hate to laugh but the thought of you constantly rejecting the EULA for weeks on end, to finally give in one day, press accept and come to terms with it, only to get in the next time and have it pop up.

      I can only imagine the amount of expletives that were said at that exact moment.

      God, I hate modern cars.

  • tuberreact 2 hours ago
    an SD card requirement is crazy
  • very_good_man 2 hours ago
    Nice! Reminds me of my jailbreaking my car's computer to write a string to permanent memory

    https://www.josephecombs.com/2026/09/08/coding-an-audi-batte...

  • fefaOd 4 hours ago
    The French auto industry... has always been "Special"
  • fHr 3 hours ago
    Shitboxing ftw
  • fHr 3 hours ago
    Meanwhile me with shitbox
  • lifestyleguru 3 hours ago
    8 inches or more of dashboard real estate to display "maps not found", "don't get distracted" warning, terms and conditions, and blinking "12:00". Having had rented a fair share of subcompact and compact cars in half dozen of countries, the car navigation was updated and working exactly only once.
  • ForHackernews 4 hours ago
    > The system had DRM checks which rejected SD cards without the correct CID (a unique ID burned into the card) and files with signatures based on that specific CID, so I couldn't even copy the files to a blank SD card.

    FWIW, there are grey market sites that will sell you an SD burned with a custom CID so you can clone an SD card with this kind of copy protection. It sounds like in this case maybe he could've gotten away with an empty maps card + menu definitions file.

    • uyjulian 4 hours ago
      There is code execution exploit in Samsung SD/eMMC firmware which, among other things, will allow changing the CID
  • nilail 3 hours ago
    [flagged]
  • npip6969 3 hours ago
    [dead]