[HN Gopher] The subtle art of designing physical controls for cars
       ___________________________________________________________________
        
       The subtle art of designing physical controls for cars
        
       Author : vsdlrd
       Score  : 119 points
       Date   : 2025-02-11 19:15 UTC (3 hours ago)
        
 (HTM) web link (www.theturnsignalblog.com)
 (TXT) w3m dump (www.theturnsignalblog.com)
        
       | mhb wrote:
       | 1. Cars should have physical controls.
       | 
       | 2. The smart knob is a clever device.
       | 
       | 3? Smart knob somehow addresses cars no longer having physical
       | controls.
        
       | xp84 wrote:
       | I applaud the author for putting thought into how to design
       | digital controls, in contrast to the "just put whatever garbage
       | on a touch screen" strategy most carmakers do today.
       | 
       | However, I still question the benefit of this complex, modal
       | control (you have to press a single knob to "cycle between"
       | multiple modes). My ancient, 2016 car features three knobs. This
       | luxury allows me to, without looking, adjust any of three
       | settings (temp, fan, air location), as well as a button which
       | does each seat heater, without any "check what mode it's in, tap,
       | look at the tiny screen, tap again if necessary" step.
       | 
       | True, in this trim, my car does not have a thermostat mode, which
       | in theory is useful, but it is so trivial to modulate the
       | temperature based on "do I feel cold, hot or comfortable right
       | now" and reaching over to twist one of the controls anyway, and
       | even in the other car I have which has this mode, I frequently
       | need to adjust things anyway, except in that car some of the
       | functions require multiple mode changes on the touch screen and
       | looking away from the road.
        
         | WildRyc wrote:
         | The author is pretty clear that having more than two modes
         | diminishes the usefulness of the interface. Three modes was
         | complex enough that he redesigned it down.
         | 
         | I've changed the channel tuner when I've reached for the volume
         | knob. If the haptic feedback between the two is clearly
         | different, that will help, no?
        
           | layer8 wrote:
           | Controls that require a feedback loop have more cognitive
           | overhead than controls you can just use "blindly" (this
           | includes not having to check for haptic feedback to test what
           | mode it's in) and from pure muscle memory. For example, you
           | learn that your preferred volume when driving on a highway is
           | at (say) the two o'clock position, and with time you'll
           | blindly turn the knob to that position without even
           | consciously thinking about it. If, on the other hand, you
           | "know" that the knob could be in a wrong mode, you'll tend to
           | hesitate when operating it because of that anticipation,
           | having to check back whether the knob is indeed in the
           | correct mode.
        
             | Animats wrote:
             | Right. This "smart" knob is symmetrical, with no pointer
             | that you can feel before turning the knob. So it's hard to
             | use without looking. This is inferior to a simple
             | mechanical knob.
        
         | oidar wrote:
         | I agree. I don't want a "smart" knob. I'm dreading going car
         | shopping sometime this next year. I anticipate having to rule
         | out a large pool of cars to keep my controls navigable without
         | looking.
        
           | residentraspber wrote:
           | I've found one good solution to this problem (for AC, at
           | least): go for a car with a good "auto" mode!
           | 
           | I hardly ever touch my AC, I just leave it on auto and the
           | car does the rest to get it to the right temperature as
           | quickly as possible.
           | 
           | I suspect this is what most automakers think the real
           | solution should be, just make it easy enough to set a temp
           | and leave the rest to the computer.
        
         | groby_b wrote:
         | There's also the fact that most thermostats do manage to keep
         | the sensor input constant, but that's surprisingly uncorrelated
         | with how you actually _feel_.
         | 
         | (Often due to the slightly bonkers idea that single sensor,
         | often not in any location the user is, will correctly reflect
         | the actual environment)
         | 
         | "Make it warmer/colder" is sufficient input and doesn't pretend
         | a precision it doesn't have.
        
         | dghlsakjg wrote:
         | My 1997 Lexus has a knob that controls the digital climate
         | control. Except that instead of a spinny position encoder, they
         | used a knob with stops so you have tactile feedback for when
         | the temperature is all the way up or down.
         | 
         | This is the kind of detail that I love about a well engineered
         | car.
        
         | carabiner wrote:
         | Toyota 3 knobs undefeated.
        
           | contingencies wrote:
           | Simplicity: are they _exactly the same_ knob, thus lowering
           | ordering costs, shipping and receiving costs, inventory
           | costs, supply chain costs, design costs, and error potential?
           | Quite likely. This also allows upstream suppliers to double
           | down on volume and work to lower costs at their end.
           | 
           | Versus... the designer of a custom complex multi-part powered
           | assembly (manufacturing cost not discussed, cleaning not
           | discussed, visibility in varying light conditions not
           | discussed) who has the fantasy that users want to squint at a
           | tiny screen on a knob while driving, and that pushing all
           | this and associated documentation down a global service
           | network is going to come at an acceptable cost to users.
           | 
           | This begs the question: who's the _real_ knob?
        
         | s0rce wrote:
         | I find the thermostat mode only works on overcast days or at
         | night as the sun contributes so much feeling of warmth when
         | driving (in California) that the heating and cooling thermostat
         | doesn't work well.
        
       | scottbez1 wrote:
       | Oh, hi, creator of the SmartKnob (mentioned in the article) here
       | - I'm continually blown away by how much UX discussion it has
       | generated over the years!
       | 
       | One of the things I regret a bit about the prototype and demo I
       | originally shared is that I used a press action and the screen as
       | a modal/menu interface. The screen makes for a snazzy demo video,
       | and works great for interfaces where you have the user's full
       | attention (like a smart home control panel) but I think there's a
       | lot more potential for just the haptics, paired with other
       | dedicated buttons to switch to specific (i.e. not a menu of)
       | modes, like this later demo I built using the haptic feedback for
       | a video timeline jog tool: https://youtu.be/J9192DfZplk
        
         | bigstrat2003 wrote:
         | The smart knob you made is genuinely one of the best hardware
         | creations I have _ever_ seen. I only wish that I was creative
         | enough to think up good uses for it so that I could put it to
         | work, lol.
        
           | scottbez1 wrote:
           | Haha, I've built at least 5 of them and my problem is that I
           | enjoy the hardware/design portion as a hobby, but writing the
           | software to put them to use feels too much like my day job,
           | so I haven't actually done anything too useful yet...
        
         | hinkley wrote:
         | There's a commercial product that looks like a fancy fancy
         | version of this and I think has a tilt sensor as well.
         | 
         | It's notable not just because it is loved by some media people,
         | both art and video, but also because it's shown up on the
         | pilot's chair in several notable sci fi movies/series with an
         | outer space theme.
         | 
         | I do want more smart devices with analog inputs and outputs
         | though. I feel like Ambient Technologies were onto something
         | but never found the market fit I hoped they would find.
        
           | crote wrote:
           | Let me guess: 3DConnexion's SpaceMouse?
        
             | 0_____0 wrote:
             | I've used it for 3D CAD and seen it on The Expanse as part
             | of the bridge crash couch props on the Martian vessels.
             | They also used an older model of Black Diamond headlamp for
             | the space suit lights in early seasons. There's a balance
             | to be struck here - too much reuse of modern objects and it
             | pulls you out of the action. I think the Expanse did it
             | well.
        
         | LoganDark wrote:
         | I wish the devkits were not out of stock!! I've been wanting to
         | get or make one of these for years
        
       | conferza wrote:
       | That's pretty cool! Thanks for sharing.
        
       | modzu wrote:
       | should read, "the _lost_ art of designing physical controls... "
        
       | uberdru wrote:
       | This is a solved problem. My 2009 4Runner has the perfect temp
       | control. I couldn't tell you how it works. But my hand knows.
       | Which is perfect tool design.
        
       | bigstrat2003 wrote:
       | Car manufacturers, please hire this guy to build your interfaces.
       | He gets it. Touch screens _must not_ be used for controls you are
       | going to frequently operate while driving the car, it 's maximum
       | unsafe.
        
         | the_snooze wrote:
         | I feel like car touch screens are designed like those 3D
         | hologram interfaces in Minority Report: they look really cool
         | and you want them, but they're entirely impractical in day-to-
         | day operation. If car manufacturers are optimizing for cars
         | looking cool in the dealership, whiz-bang touchscreens win over
         | boring physical controls.
        
         | groby_b wrote:
         | I wish that was the unsafest thing car manufacturers did.
         | 
         | Jeep, for example, has just discovered a predilection for
         | random full-screen alerts with a blaring alarm sound, if, for
         | example, they magically inferred there's a tow-truck somewhere.
         | (There's about a 50% chance you'll encounter a tow truck in the
         | next 10 minutes, at best)
         | 
         | This is great if, say, you're three hours into a night drive,
         | all alone on the road, and suddenly ALARM THE WORLD IS ENDING.
         | 
         | I actively hate car manufacturers. They should not be allowed
         | to use touch screens. Even if they could be useful - they have
         | repeatedly proven they are too stupid to use them well.
        
         | m463 wrote:
         | I'm pretty sure car manufacturers "get it" too, but the
         | marketing team/parts count person has a conflicting agenda.
        
       | _tariky wrote:
       | My Skoda Superb(2015) have very similar knobs for controlling
       | temperature and when pressed it turns on seat heater.
       | 
       | From the first time I used it. It felt so natural and intuitive
       | to use.
       | 
       | But unfortunately touch screen infotainment system is pure
       | garbage.
        
       | Animats wrote:
       | Mandatory XKCD.[1]
       | 
       | [1] https://xkcd.com/2704/
        
       | 51Cards wrote:
       | Kudos for to the author for the work put into this and the
       | intelligence functions are interesting. I do have a couple
       | concerns though.
       | 
       | A. Trying to design down to two knobs makes each knob multi-
       | modal. This removes a lot of muscle memory benefits requiring a
       | glance at a screen, a small screen that is now partially covered
       | by your hand while operating the knob. Haptic feedback might be
       | able to help you know what mode you're in without looking but now
       | you have a lot more to memorize to use it while keeping your eyes
       | on the road which may begin to defeat the simplicity benefits.
       | 
       | B. Haptic feedback... will this work with gloves on? (will you
       | feel it, will it sense your touch)
       | 
       | A lot of manual systems now have 3 knobs, not much more than the
       | 2 presented here, which will always do the same thing each time
       | you reach for them. My concern would be how long it would take
       | the user to be familar with the interface without looking. One
       | quick thought, I would be inclined to think that feedback through
       | a large screen not covered by your fingers might have advantages.
       | 
       | It's a great study on UI consistancy however, esp around how to
       | program the detents, etc.
        
         | crote wrote:
         | I think the multi-modal stuff can be mostly fixed by dedicated
         | mode selection buttons, which can be blindly pressed to enter a
         | specific mode. The logical option would be to place them around
         | the dial like a pie chart, as that would be trivial to find
         | without looking. Place those buttons _underneath_ the dial
         | instead and you can use the display as a clear mode indicator
         | as well, without the hand obscuring it.
         | 
         | You could also put a copy of the display somewhere in the
         | driver's HUD. It'd still draw some attention, but having it for
         | example temporarily fill up the center of the speed dial
         | (perhaps in some way only when the driver is touching it?)
         | would be a lot less distractive than having to look all the way
         | over on the infotainment panel.
         | 
         | As to B: it's a physical knob, with a motor pushing against
         | your turning force. It'll have zero trouble with gloves.
        
       | pmontra wrote:
       | A very tangential note about this:
       | 
       | > Much like a door handle should communicate whether to pull or
       | push a door,
       | 
       | For many common doors it's not the handle, it's the frame.
       | Standing on one side of the frame we see that the door is free
       | and we can pull it. On the other side we see that the door hits
       | the frame and we must push it.
        
         | crote wrote:
         | Yeah, but it's not _supposed_ to. With good design it is
         | immediately obvious whether the door is push or pull - even
         | when the frame doesn 't have any clear indications. For
         | example, the door in [0] (apologies for the YT short) has no
         | immediately clear hints if you look at the frame or handle.
         | 
         | Both sides look exactly the same, so how are you supposed to
         | know? Add a "push/pull" sticker you'll miss 90% of the time?
         | 
         | The Vox vodcast(?) in [1] goes a lot further into the problem,
         | starting from a very similar door. The solution is pretty
         | simple, in hindsight: if they designed the door properly, you
         | won't even be _able_ to pull on a push door. Have a pull handle
         | on the pull side, and a push _plate_ on the push side.
         | 
         | [0]: https://www.youtube.com/shorts/oJnEjV8vQJg
         | 
         | [1]: https://www.youtube.com/watch?v=yY96hTb8WgI
        
       | Terr_ wrote:
       | I wish car manufacturers would refocus from touchscreens (for
       | reasons I will assume everyone understands) to a cost-cutting
       | compromise of _modular_ physical knobs and buttons.
       | 
       | Imagine if there was a standard form-factor, so manufacturers
       | could install a 1x4 unit and then plug in a line of dials or
       | button-clusters, where each section has its own tiny display that
       | can be software-controlled to show what it does.
       | 
       | Yeah, it won't always match the exact lines and swoops designers
       | want to use, but I want usability, I don't buy a car to show off
       | the interior to others. The people who _do_ do that are probably
       | buying much more expensive cars and can easily afford to do
       | things the classic way.
        
         | crote wrote:
         | Cars used to have modular buttons. It was _very_ common to have
         | a couple of blanks in your infotainment cluster.
         | 
         | The problem is that it still requires custom per-feature
         | assembly. A single car model needs a dozen different button
         | configs, with a dozen different wiring harnesses. That's a lot
         | more expensive than a simple one-size-fits-all touch screen you
         | install into literally every single car and configure with a
         | software flag.
        
           | reaperducer wrote:
           | _Cars used to have modular buttons. It was very common to
           | have a couple of blanks in your infotainment cluster._
           | 
           | My brand-new luxury-brand EV still has blanks. Not all trim
           | levels get the rear fog lights, or a few other things I can't
           | remember. Also, they're used for buttons related to adding
           | the towing package.
        
           | Terr_ wrote:
           | AFAICT those were generally modular _per trim level_ , and
           | mainly involved excluding features at lower trims.
           | 
           | What I mean is something that is modular per-manufacturer or
           | maybe even across manufacturers, where customization comes
           | from the arrangement in a grid and what is pumped through
           | each control's little display screen to identify its purpose
           | and status.
           | 
           | Installation would be a matter of screwing in a block of
           | sockets, plugging in a wiring harness, and then snapping in
           | the commodified dials/buttons/multi-button-clusters.
           | 
           | > A single car model needs a dozen different button configs,
           | with a dozen different wiring harnesses.
           | 
           | That seems to assume every button/dial will have a direct
           | connection, I'm thinking it would all terminate in the block
           | of sockets, which the manufacturer would program with logic
           | like: "Analog input in socket 1 controls resistance on wires
           | A and D with the following mapping. When value is in this
           | range, show this picture."
           | 
           | The motivating idea here is: "Can we keep a variety of
           | physical controls while making them cheaper, more-functional,
           | and easier to repair?"
        
       | jimkleiber wrote:
       | This is one of the many things my dad did in his 40+ year career
       | as an engineer at GM. I'm really excited to share this with him
       | and grateful for such a write-up.
       | 
       | A big thank you to the author, the person posted it here, and all
       | those who upvoted it.
        
       | steezeburger wrote:
       | Reminds me of m5stack's dial
       | https://shop.m5stack.com/products/m5stack-dial-esp32-s3-smar...
       | 
       | I got a few to play around with for my home automation system,
       | but haven't had the time.
        
         | scottbez1 wrote:
         | The m5stack dial is just a screen with rotary input ring, but
         | doesn't have haptic feedback. They actually just launched a new
         | product the roller485 or rollerCAN that in theory is a nice
         | off-the-shelf BLDC haptic knob, but I haven't had a chance to
         | play with mine yet
        
       | dlcarrier wrote:
       | Designing car controls is easy. You take what engineers have
       | spent 100 yeas fine tuning every element of, for precision and
       | ergonomics, then you give to someone with an industrial design
       | degree who throws it all out the door to make something shiny,
       | and it kills Anton Yelchin, amongst others.
        
       | hammock wrote:
       | It's Google Nest for your car.
       | 
       | OP mentions the Braun work on pots (potentiometers, the common
       | lingo for rotary dials). I suggest they also check out the entire
       | subculture around pots and faders in the music industry, where a
       | lot of thought goes into them as relates to mixing board design
       | and experience.
        
       | jillesvangurp wrote:
       | I think a good analogy here is retro digital cameras. I have a
       | Fuji X-T30, which is about five years old now. Still a decent
       | camera and it has a lot of physical controls. Except they are not
       | really physical controls. They are buttons and dials that are re-
       | programmable. Even the aperture ring on my lens is not physically
       | connected to anything. The aperture is controlled digitally. The
       | aperture ring just gives off a signal to the camera that is than
       | hooked up to the aperture. Some lenses even have re-programmable
       | buttons now. Some cheaper lenses don't have dedicated controls
       | like that. But you can still hook up one of the other dials on
       | the body to do the same. There are wheel-button thingies on the
       | front and the back that you can bind to whatever.
       | 
       | Cars basically could use controls like that. Maybe with some
       | sensible defaults; and there's going to be a bunch of things that
       | most people would like to control with a button or a dial. Not
       | that hard to execute and you can sell cars with more and less
       | dials. Or no dials at all. The touch screen is always the cheap
       | fallback. The buttons are a nice up-sell. And with the right APIs
       | and wireless protocols, it wouldn't even be too hard to have
       | third party bluetooth buttons even; or a strip of buttons that
       | plugs in a USB socket. Or similar. You can buy flight simulator
       | hardware that emulate most of a modern cockpit with physical
       | buttons. Most of these things are USB devices. Some of these
       | things are pretty affordable even. Throttle compartments, landing
       | gear buttons, buttons with a satisfying click/thunk/etc. Whatever
       | you want.
       | 
       | Like it or not, this stuff is basically cost related. Buttons
       | have lots of wires, components, etc. That increases cost of
       | assembly and bill of materials. They can also break and cause
       | additional cost under warranty. People need training on how to
       | install and repair that stuff. The nice thing with a touch screen
       | is that it's just a handful of components and wires. Installs in
       | no time and if it breaks, it's easy to replace.
       | 
       | So, the question for manufacturers then becomes what is the car
       | with the least buttons that drivers still pay a premium for?
       | Because, that's the most profitable for them. And the reality of
       | course is that what people say what they'll buy mostly doesn't
       | match their behavior in the show room.
       | 
       | It's the same with a lot of products. It doesn't matter whether
       | people are buying a TV, a phone, a new laptop or whatever. Some
       | people really know what they are buying, but most don't, and some
       | only think they know and talk themselves into buying crap they
       | definitely are not going to be happy with.
       | 
       | In the end, people mostly just select the thing with the largest
       | feature matrix that still fits their budget. And the nice thing
       | with software features is that there's no assembly or component
       | cost involved. Modern cars are smart phones with wheels.
       | Literally made by smart phone manufacturers like Huawei and
       | Xiaomi even (both sell lots of cars in China).
        
       | costcopizza wrote:
       | One overlooked feature of physical controls is that they also
       | give interiors an identity and experience.
       | 
       | Growing up obsessed with cars, I loved seeing how different
       | brands would lay out the cabin. Volvos from the 2000s used a
       | rather large diagram of a seated person to select the HVAC vent
       | for example.
       | 
       | Also, in my brain, a 3000+ pound object just dang requires some
       | stuff to physically press, push, and hear click!
       | 
       | A couple giant touchscreens with touch controls nearly eliminates
       | that.
        
         | masklinn wrote:
         | > Volvos from the 2000s used a diagram of a seated person to
         | select the HVAC vent for example.
         | 
         | ... don't all cars do this? I can't remember seeing anything
         | other than that to represent which vents are active.
        
           | rdlw wrote:
           | Here's a picture: https://www.media.volvocars.com/uk/en-
           | gb/media/photos/47385/...
        
         | russellbeattie wrote:
         | I get what you're saying, but I totally disagree with it. It
         | reminds me of mid-2000s Nokia, where each year they completely
         | redesigned their phones simply to change them. It turned out
         | what people wanted was a brick with a few common buttons, a
         | nice screen and a standard GUI.
         | 
         | The main problem stems from the fact that car manufacturers
         | will always choose novel designs over usability. They change
         | components not to improve functionality, but simply for
         | differentiation. As you pointed out, even if a control is well
         | designed like Volvo's HVAC, it's phased out during the next
         | refresh.
         | 
         | A newer problem is that every single car maker is beyond
         | incompetent when it comes to software and UX. It's not part of
         | their culture and expertise. So in addition to bad or missing
         | buttons, even the screens are a nightmare.
         | 
         | This is an entrenched idea in the automotive industry, so it
         | probably won't change, but it's something that really needs to
         | stop in my opinion.
        
       | nraleigh wrote:
       | This is nice. So tired of touch screen controls that I can't
       | access without breaking my focus from driving. This is a nice
       | middle ground where you can display rich graphics if you're
       | looking down at the knob, but can also control by feel without
       | losing focus.
        
       | maxglute wrote:
       | Standardizing voice control in cars will go a long way until
       | vendors decide to standardize physical controls or car OS. I
       | should be able to get in any car and say "Set heat to X",
       | "Defrost Windows" etc.
        
         | wnissen wrote:
         | Told a rented Telsa "Turn on wipers". It replied that it didn't
         | understand "Turn on vipers". Yes, car, I have a basket of
         | venomous snakes in the back and wish them to be activated!
         | Bravo!
         | 
         | Once LLMs are a lot better at understanding intent, that is
         | probably what we'll get, since it will be cheaper than even
         | bargain basement mechanical controls.
        
         | thecrumb wrote:
         | Does that work with kids talking in the backseat, the radio
         | playing, GPS reading directions out loud, all at the same time?
        
         | bbarnett wrote:
         | You should! Choice is great. I also should not have to talk to
         | my car, I hate doing so.
        
       | tiffanyh wrote:
       | I'm always reminded of the QuickTime v4.0 volume rocker and how
       | painful it was to use.
       | 
       | Screenshot:
       | https://www.macintoshrepository.org/_resize.php?imgenc=ZmlsZ...
       | 
       | Fortunately, it was changed to just a slider in v5.0 as seen
       | here: https://jablickar.cz/en/wp-content/uploads/2018/12/Apple-
       | Qui...
        
       | ge96 wrote:
       | Is that over kill to use a BLDC for a dial? They are pretty cheap
       | nowadays
        
       | thecrumb wrote:
       | As I get older the one thing these designer overlook is aging
       | eyesight. My Honda has decent controls but the small display
       | (like on these knobs) is very difficult to see sitting still. At
       | night, while driving - it's impossible. The icons are tiny. Given
       | the size of the current screens in cars - that's a lot of real
       | estate for knobs. Use it.
        
       | usaphp wrote:
       | I like controls in the upcoming Rivian cars, it's basically
       | changing the physical feedback based on what you are selecting
       | [1]
       | 
       | 1 - https://youtu.be/k0Gt_PUyldc?si=VxK1rzWr0Vx0JUHd&t=371
        
       | insane_dreamer wrote:
       | My favorite car control system is the BMW iDrive rotary dial.
       | 
       | Touch screens are fine for given much more fine-grained access to
       | controls. But they should be limited to controls that you _don't
       | need to set while driving_. It's absurd that it takes 3 taps on a
       | screen -- diverting my attention to the screen -- on my Tesla to
       | turn on defogging (a common event here!) while I can do it with a
       | one touch (now muscle-memorized) on my Subaru.
        
       | NotYourLawyer wrote:
       | Touch screens are such a lazy, shitty, dangerous way to implement
       | 90% of the functions they're currently used for. Good to see that
       | at least one person is working on this problem.
        
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       (page generated 2025-02-11 23:00 UTC)