Pragmatic 66: Haptic Taptic Tactic

6 November, 2015


Apple are pushing Haptics in more of their devices each release. We look at why they are and how they’re doing it differently.

Transcript available
Welcome to Pragmatic. Pragmatic is a discussion show contemplating the practical application of technology. By exploring the real-world trade-offs, we look at how great ideas are transformed into products and services that can change our lives. Nothing is as simple as it seems. Pragmatic is part of the Engineered Network. network. For other great shows, visit today. Pragmatic today is brought to you by many tricks makers of helpful apps for the Mac. Visit many tricks or one for more information about their amazingly useful apps. We'll talk about them more during the show. I'm your host, John Chidjie, and I'm joined today by my co-host, Carmen Parisi. How's it going, Carmen? Pretty good, John. How about you? Very good. Thank you. Very good. Wonderful. I'm ready to talk tech and authoritatively sip my AeroPress coffee. Oh, really? Nice. Yes. Well, I actually had a cold brew coffee, but I heated it up first, which is may sound confusing to some people. But sometimes that's what I do in a hurry. It's actually quieter that way, if that makes sense. Because it's nighttime and everyone's just gone to sleep here. So you know, concerned about waking up the kids. I try pre ground my beans last night, so I didn't wake up the wife. Ah, nice. See, that's it. There you go. It makes perfect sense then. Cool. So just to one of the things that I was hoping we could talk about today is, I suppose, in recent times and the last 12 months, Apple has been moving away from vibration. Well, they're changing their vibration technology that they use for discrete message indication and they're moving away from vibrating like rotational motors and they're moving to linear motors and they're calling it their "taptic engine" and that was in air quotes for those that have a big picture of that "taptic engine" which is just a form of haptic feedback. And I guess maybe that's where we should start. How about you? Would you like to lead in and explain to listeners the differences just quickly? Sure, sure. So we'll back it up first. So there's the difference between just plain old vibrations and haptic feedback. Vibrations are more old school and they're generally just used to get the user's attention. They're very cheap to implement and they're good for simple on/off applications or for safety applications when you just want to say "Hey, something's going on!" You have a message, you have an email, whatever, "This alarm's going off." Haptic is more complex than a simple vibration and it's more costly to implement because of that and it's used in things like touchscreens and video game controllers, stuff like that, where you want more than just an on/off. One example would be a car reversing, if you have a backup camera, and maybe some feedback in the steering wheel. A vibration would just vibrate when you're a certain distance from an object, 50 inches, 3 feet, whatever. A haptic feedback would vibrate the steering wheel at a different strength and different frequency to give you a a more detailed view of how far you are away from things instead of just, boom, you're too close. Yeah, cool. Very good. Yeah. All right. All right. With respect to the whole vibration thing, because I guess vibration, okay, we're electrical engineers so I can still have an opinion about vibration because I know it's a mechanical phenomenon but still, I don't care. I mean, essentially it's an oscillation centered around a given point. vibrations, they're not generally an issue or they're not generally, I don't know if that makes any sense, but I guess it's more the periodic repeated oscillations around a common point when they amplify and resonate. And sometimes you want that like a tuning fork, but other times you don't want it. And the funny thing is actually, if you, in my line of work specifically, vibration's generally your enemy, you know, because vibration leads to fatigue stress and to failure of components. So vibration sensors like, for example, some of the gas turbines that I work on, gas compressors, water pumps, wastewater and wastewater pumps, vibration is bad. And eventually, if it's left unchecked, the imbalance that causes a vibration will destroy the equipment if it's left unchecked. So I guess for me, the funny thing is talking about vibration is that vibration is generally destructive in my line of work. But when we're talking about electronics, vibration in this case, it being used for messaging is obviously, well, we hope not destructive. I suppose if you left it vibrating like constantly all the time, you probably would cause fatigue stress in some of the solar joints or solid joints, depending upon which hemisphere. But still depending on how good your QA department was. Yeah. Yeah, well, I suppose so. But I mean, I guess I wonder if I'm anyway, never mind that that that's a wrap. Now you got me doing a thought experiment. And our listeners who may not know, you ceramic caps can vibrate due to what's called electro restriction, which is the inverse of the piezoelectric effect. Electrical forces cause mechanical motion, instead of mechanical causing electrical motion. And I was wondering if you could get the vibrating engine to vibrate at the same frequency as the caps and just have some kind of crazy feedback loop. That'd be kind of cool. Yeah, experiment. It would wreak havoc. I'm sure. Okay, because it gets into the audible range and you can hear your phone vibrate. So yeah, well, that's true. I guess it's possible to couple in, but I don't know. Yeah, we'll talk a little bit about the audible thing later, too, because I've got to admit that's one of the things that I can't stand about vibrating motors, but that's okay. So, all right, if you want to know more about things like the differences between free and forced vibration, damping and so on, then feel free to read up as in the Wikipedia link, knock yourself out. It's very mechanical and that's probably why I'm just going to let it go there. But yeah, feel free to learn more. Very interesting. But you know, so anyway, all right. So a little brief history. When pagers came out, pagers, pagers as in, you know, the silly things that back in the 80s, I think it was, they were all the rage. Yeah, I think drug dealers and doctors use them. Drug dealers? The drug dealers? Yes, okay. Let's focus on the doctors, the legitimate professions. There we go. So they were the only ones that could afford one because they were also always on call, right? So you'd have this thing, you clip it on your belt and it was about the size of a deck of playing cards, I suppose, and it was a heavy plastic thing. Anyway, so the vibrator would just simply go off and let them know that there was a message for them. Obviously, things have changed. They've reduced in size and power and so on, but they were supposedly discreet. But like you said, a lot of these vibrating modes are quite audible. I did talk about some of this stuff briefly on episode 38, Watch This Time and Space, which there'll be a link in the show notes if you want to go back and listen to it. But when the Apple Watch came out, though, it was different because they're not using the traditional rotational off-center mass vibration units that they have in the past. Those particular ones are called ERMs, which is eccentric rotational mass. Instead, Apple decided they're going to go with a linear actuator, which is a linear resonant actuator, or LRA for short. The thing is, all of Apple's previous devices, all their iPhones prior to that, all used ERMs. first device to use an LRA was the Apple Watch and that's why I found that to be interesting. At the time, I asked John Gruber on Twitter because he had a test unit and hardly anyone else had one. I asked him if it was audible or not and he actually went into a cupboard, closed the door and was able to confirm for me, tweeted back at me and said, "Nope, you hear it. It was just, you know, it was silent. And I like the silence, you know, it's just, I can't stand the noise. So it was for me, that was one of the key decisions why I got it myself an Apple Watch in the end. But what's happened since that moment is that Apple have now released a whole bunch of products that incorporate this thing they're calling the Taptic Engine. And they call it Taptic, I guess, because it feels like a tapping sensation, is something that you can't really emulate within an eccentric rotational mass. And it's because I suppose the vibration profile is different. So, like very different. What they've done with the haptic engine is they've given it two names. Apple have given it two names. One of them is it's coupled with their touch technology. And it's a bit interesting. They're two different things. You've got forced touch and you got 3D touch. And the haptic engine is involved in the feedback for both of those. So it's sort of like the feedback component of those. And the thing to keep in mind, though, is that the actual haptic engines that are behind them, that are actually totally different between them and the overlap isn't isn't the same, maybe not making sense. So, OK, on the Apple Watch and on the iPhone 6s, 6s Plus, they use a linear moving mass in their LRA. Whereas on the Magic Trackpad 2 and the MacBooks and the MacBook Pros, they all use a series of four independent weights and they are all individually actuated underneath the trackpad. It's actually different. It's like the naming of the technology that they're using. They're using force touch on one, 3D touch on the other, but one of the 3D touches, which is on the iPhone, is actually using the same actuator as in the Apple Watch, which they call force touch. It's confusing. It's just marketing. I get it. I know that. But you know, so I don't want to talk about the 3D touch or the force touch or anything like that. That's just marketing. I just want to talk about the actual linear actuators and the differences between them. So let's forget that the actual units they use don't align with the branding. Okay, so the linear actuator is balanced between two springs. So if we can imagine that there's what they call a moving mass, and this moving mass is just a hunk of steel, nothing special. I think I read that they were like neodymium magnets. Yes, yes, that's right. Well, are we sure about that? Because I had a look it was now there's actually precision micro drives. I think. Yeah, that's what I was looking to. Yeah. And Precision Micro Drives do manufacture these LRAs and a bunch of other ones as well, some ERMs. And they talk about those magnets, but I could not find a definitive equivalence with the one that Apple's using. What seems pretty clear to me is that the design of the one that Apple is using, it's either Apple designed or it's not a publicly available product. It appears to be something that's been made for them. So it's not something that you can look up the specs for. It's not like a standard chip. It's more like an ASIC kind of thing, I guess. But anyway. Apple is special. Well, yes, yes they are. But I guess the point is that it's not something you can just buy off the shelf. You can't just dial up these guys and say, "Hey, give me one of these Taptic things. It's something that they are manufacturing specifically for Apple. And that makes it difficult to get specs on. So what we know, we know based on teardowns, what we know, we know based on X-rays that people have taken, disassembly and some, not all the information is available. So we'll get some of the detail in a minute. But anyway, all right. So your Apple Watch is displayed in front of you in pieces just for this podcast. That's dedication. No, I did actually briefly consider it was brief. It was I don't know if it was in the seconds range of brief, but it was a brief moment where I'm like, you know what the heck with this, I'm going to start pulling my my watch apart to get the dimensions and the masses that I'm looking for. And then I'm like, no, I'm not. You're never getting that back together. No, that would be an example of the barometer that I took apart when I was a kid that also did not go back together. Anyway, it's all good. So yeah, okay, right. I just need to get back on topic now. Then that is okay. So, mobile, I guess I want to call the two different Taptic engines just to differentiate them. The mobile Taptic and the desktop Taptic. Taptic. Oh, haptic, taptic, tactic. Gosh, sorry. It's a tongue twister. All right. So the mobile Taptic and the desktop Taptic. Almost did it again. Now, there's a link in the show notes. Twister episode. - Oh yeah, tell me about it. Step 12 of the iPhone 6S Teardown by iFixit has an actual X-ray video, which is so cool, of the actual Taptic actuator in action. And you can see this thing when they send the pulse to it, and you can see it vibrating back and forth. So the moving mass moves from left to right. It's held in place between two springs, and there is an electromagnet coil working against a magnet of some description and neb... nebda... you just said it before... mullab... probably a mullab... thank you. Yes, that one. This is why you're on the show, man. You can pronounce all the stuff I can't pronounce. Well, you did say you liked that on my resume. I did, yes. Yes, good. It came with... can pronounce really big words. Lovely. So anyway, magnet thing. So anyway, and the idea is that you pulse that once or twice and it will then react against the magnet and of course you can then reverse the polarity of that and it will then stop it and that's the whole point is that you have very precise control based on the damping of the springs as well would determine how long it will oscillate for naturally before you stop it. Anyway, so the key element for me is the actual mass, the actual mass of that moving mass and that to me is what's interesting. So I'm going to focus and explore on that the most during this episode because I find that fascinating. But anyway, so the x-ray video, it only goes for maybe 10 seconds or so, shows about two or three pulses. Very, very cool. Highly recommend checking that out. Now the desktop Taptic Engine, they have a disassembly of the MacBook Pro 13-inch. So steps 11 through 14, again, link in the show notes, love iFixit, shows what that looks like. And you you can see it's completely different. So as I say, four separate coils, four separate moving masses contained therein. So it's very, very different. They're working, well, they're working, sorry, they're working against a common bar, if that makes sense. It's hard to describe in words, but it's a very different actuator. Okay. And I suspect the four different actuators, they're pulsed in groups, based on the amount of haptic feedback they actually require. So let's say, cause on the MacBook Pro, when you, when you push down just gently for a single tap, you'll get a very light response and that mimics the physical switch that you would ordinarily be pushing from the older track pads. And a force press will give you a much heavier response and that probably uses multiple actuators. So I suspect that it's actually pulsing one, two, three or four of them on or off based on the intensity of the tap sensation that it's trying to replicate. So, and you can actually feel it very carefully. If you put your finger, let's say you've got two hands, presuming most people would have two hands, put one index finger on the left-hand side, one on the right-hand side, but only press down with the one on the right. And then on the left, you can feel the sensation much clearer. When you're pressing down on something, it changes the response and the nerve endings in your finger. So you want to have one that you're just using just for feeling. Anyway, so you can feel through the other finger, the tap profile, the vibration profile as you're pressing down on the trackpad. So it's very clear when you do that, you can feel the different stages and intensities of the haptic feedback through the trackpad. So anyway, one of the other things that's also interesting is if you take your sensing finger if you'd like, off of the actual trackpad surface and onto the body of the MacBook Pro or MacBook, whatever you've got with the Force Touch trackpad, it's much less pronounced on the main body of the MacBook Pro, like significantly fainter. And there's a good reason for that. We'll talk about it later. Okay. So before we go into all of the details and the numbers and the figures that I'm just, for whatever reason I find interesting, is I just want to say again, okay, try as I might, I just, I could not find the exact piece of information I was looking for. Right. I could not get all of the dimensions. I could not get all of the masses because when they pull these things apart, they meaning I fix it and tear down sites and so on. For whatever reason, they didn't get out the micrometer and tell me exactly how thick the battery was exactly how thick the Taptic engine was. They didn't pull apart and say, Oh, the spring weighs this much and the moving mass weighs this much. So unfortunately, and with the lack of manufacturing details, we have to make a few assumptions. I think they're fair assumptions and I think they make the point, but let's just see where that takes us. OK, so the Apple Watch, let's start with the Apple Watch. I meant to ask, Carmen, now, I know you don't have a Mac, you don't have a MacBook Pro or a MacBook laptop, correct? Correct. I have my nice new Windows desktop. Very good. No problemo. I can't remember if you have an iPhone. You have 5S. I got a 5S. Okay. So yeah, 5S still has the original eccentric. I wonder if we should just call that man. That's what the eccentric feedback. I'm an eccentric man. That's why I picked it. There you go. See that fits perfectly. Anyway. All right, good. So then the next one is do you have an Apple Watch? No, I do not. Okay. Okay, so that's okay folks. just lean on the fact that I have an Apple Watch, a 6S Plus and a MacBook Pro. You are the authority. I guess, well, only between you and I in this conversation, I guess, but plenty of other people I'm sure may have these. But anyway, all right. So I have a 42mm sport Apple Watch. So we'll start with the Apple Watch. Now the Apple Watch was introduced on the 24th of April this year. 2015 in case you're listening to this in the distant future. The sport model 38mm model weighs about 0.88 ounces which is 25 grams. The 42mm one which is what I have is 1.05 ounces which is 30 grams. That's the body of the watch, that doesn't include the band because all the bands have a different mass. The stainless steel model is a fair bit heavier, 1.4 ounces for the 38mm that's 40 grams or 1.76 ounces for the 42mm that's 50 grams. I just want to talk about the sport at this point. So there's a tear down and I fix it. Like there's tear downs and I fix it because I love them. Anyway there's a link in the show notes and it shows the Taptic Engine and on step 14. So the thing to keep in mind is there's an x-ray comparison, again link in the show notes, showing the 38mm and the 42mm. Each watch has a physically different sized taptic unit, and I think there's a good reason for that. As I said, searched far and wide, could not find anyone that had mentioned the moving mass, so we're going to estimate it by a few facts. First of all, we get the relative size because we know the size from the x-ray photos relative to the rest of the body size of the actual units, which we do know those numbers. The Taptic engine is encapsulated in a case. That case is the same depth as the battery depth. The battery depth based on the scale images is about 5mm deep on the 38 and the 42mm. So if we assume that the shell of the Taptic consumes about 2mm of usable height, that's given the thickness of the shell itself as well as the air gap clearance around the moving mass to let it move freely, then let's say that the moving mass has got about a 3mm depth. Now I think that's a perfectly reasonable number because if you look at the 6S and the 6S+ then those I do have measurements for that are precise, and we'll talk about them later, then 3mm is in that ballpark. So I think it's a reasonable estimate, guesstimate, to run with. So, approximate outside dimensions of the 38mm moving mass is 10.3x11.3x3mm. Again, the 3mm is assumed. Now, inside the moving mass is actually a cutout, it's like a rectangular cutout, and you know, for reasons. And its dimensions are 6.1x6.3x3mm. So it gives us a total volume of metal that the The moving mass is about 76 cubic millimeters. Now on the 42 millimeter model, its moving mass is 13.6 by 11.2 by 3 and its inside dimensions are 6.8 by 7.1 by 3 and that gives these a total volume of metal of 106 cubic millimeters. Next assumption, the density of steel. And I know that the density of steel is going to be relative to what alloy it is. Okay, so, okay, obviously. I don't know what alloy it is, so I didn't pull it apart and I didn't put it in a... Oh dear. What do I call those things again? Mass spectrometer? Yeah, or gas chromatography? No, that's for gases. No, gas chromatography. I'm, you know, the... I just wanted to say more big words. Oh, well, you did... Okay, that's okay. Fine, you win. But anyway, no, I did not figure out what kind of metal it is. I'm going to assume it's just ordinary steel, okay, because it's cheap and simple. I doubt it's stainless. It might be, who knows. So let's just run with it. An average, that's about 7.6 grams per cubic centimeter. So we're going to convert all this out and figure out that the 38 millimeters moving mass is about 0.6 of a gram. That's about 2.3% of the overall mass of the watch body itself. The 42mm weighs in at about 0.8g, that's about 2.7% of the total weight of the watch body. It's interesting, you can move something so relatively light and actually feel it on your wrist. Yeah, well you see this is the whole thing, this is what I find fascinating, right, is that what you would do if you were designing this is you've got two things you're trading against. saying, "I need to have the most distinct sensation of tapping that is not too faint but not too strong because if you make it too big and heavy, that's going to consume more energy in order to actuate it. If you make it too big and heavy, it also adds to the mass and the weight of the watch itself. Obviously, it also takes up more physical space. You have to minimize it as much as you can because you want to make it light as possible, but you still want to be able to feel that tapping sensation. And I would say that the figure that they probably settled on was around about two and a half percent. The moving mass had to be about two and a half percent or thereabouts of the mass of the overall body of that watch in order to make it a consistent sensation. Because if they didn't care, if they just wanted to have a common, you know, like the keyboard. The keys in the keyboard, right? You're like, who cares? All the keys are exactly the same. So the letter Q is always the letter Q, no matter where it is, always the same. So it doesn't matter. If the Taptic Engine was like the letter Q on a keyboard, well, it would just be the same size, same dimensions for every single product, but it isn't. And I suspect the reason why is because they wanted to have a consistent tap sensation across all of the different watches. what I would love to know, and I don't have the information for, is I'd love to know the actual mass exactly, and I'd also love to know the mass of those in the gold and in the stainless steel models. Because if my theory is correct, then I would suspect the Taptic engine would be slightly heavier. Whether that's thicker, wider, longer, whatever, I suspect it would be probably slightly thicker. So the dimensions of the actual Taptic unit case would have to be the same between the different models, but the moving mass inside would probably be different. The cutout size. Yeah, it wouldn't surprise me either if they did that. Yeah, because otherwise, you know, anyway. So anyway, that's the watch. So let's talk about the iPhone 6s and 6s Plus. Actually, you know what? Before we do, let's just quickly talk about our sponsor for this episode and that's ManyTricks. 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I have far more precise dimensions and for these, which is interesting. So the Taptic Engine in that particular case was 35 by 6 by 3.2. And the Taptic, oh, that was a 6S and the 6S Plus is 15 by 8 by 4.9. And that's the part that's interesting. because if you look at that 672 cubic millimeters for the 6S and 588 cubic millimeters for the 6S+ but here's the problem I don't have accurate figures for the moving mass those dimensions are the external dimensions of the Taptic unit this is when I felt like pulling my phone apart because I really, really wanted to know and I have done everything I can think of and I simply cannot come up with a decent set of approximations because I don't have enough photos of it pulled apart. All I have is an x-ray. So, unfortunately, I can't apply the same logic to the 6S or the 6S+. However, what I can say from personal experience is that the 6S+ that I have is really, it actually is audible. Like I can hear it, not just feel it, unlike the Apple Watch. I wish I had more information on the 6S and 6S+, unfortunately I just don't. If someone out there can get me those dimensions, I'd love to run the numbers, but you know what, unfortunately, unless I go and have a complete fit of insanity, I'm not going to strip my own iPhone 6s Plus. Although the thought occurred to me of scouring eBay and looking for someone who destroyed theirs and then maybe get one and pull it apart, but it's probably too soon for that. I think most people, the supply hasn't been so constrained for the 6s, 6s Plus as it was for the 6s and the 6 Plus last year. But even so, I can't imagine that it'd be too many broken ones for sale at this point. Broken Apple Watches maybe. Does iFixit sell the Taptic parts to replace it in your iPhone? Because then you just buy what you need. Yeah, I know. And I looked and I couldn't see them. So, yeah, well, you buy a new phone and expense it to Engineered FM. Engineered Network. Yeah, I was going to say, yeah, no, no, not doing that. Yeah, we're rolling in that sweet podcasting money. Why not? Yeah, that's right. Exactly what we're doing anyway. All right. Good. Lovely. Well, there were a couple of little notes I did make, though, about the 6s and 6s Plus is that they are actually heavier. Both the 6S and the 6S+ are heavier than the 6 and the 6+. So they're heavier than last year's model and part of the reason is the Taptic Engine. It absolutely is. Unfortunately there's also more mass, about an extra 15 grams more in the mass of the screens. And another interesting factoid for you is that the 6S+ they sacrificed a little bit of the battery in order to fit the Taptic Engine in there because these things take up a lot more space than an ERM and it's interesting that they made that trade-off. So clearly Apple has decided that that's a trade-off worth making. So these things, they're bigger, they're heavier and they are although... Okay, so you know what? Over to you. How about you to go through some of of the reasons why you think it would be better. Let's just compare and contrast the differences between the ERM and the LRA. Why on earth would you consider going to an LRA over an ERM? Why would you do that, do you think? Well, it's much less power hungry than an ERM. The reason for that, we could spend a whole episode talking about resonance and series in parallel resonance, but if you model an ERM electrically as an RLC circuit, it's a series resonance circuit, and an LRA when you model it electrically is a parallel resonance circuit, so the R, the L, and the C are all in parallel instead of just in series. And the simple high-level view just for this podcast, in a series resonance circuit, the The current going into the motor is maximum at the resonant frequency and in the parallel resonant frequency, the LRA, when you're at resonance, the current is at a minimum. So you're using less power to drive it than the ERM. Yeah, and obviously that's a big deal because you're trying to conserve your energy. So if you do cut off a little bit of your battery size, you're actually winning as a net win overall because you're using less energy in the end every time you use the vibrating motor. Yes, correct. Seems like a good trade-off to me. The other thing that's interesting also is the different haptic profile that you can generate with an LRA. So, for example, when you've got rotational energy, you've really only got on or off and the speed at which you rotate. But the problem is that the amount of energy required to get up to a speed at which the vibration reaches the actual level that you're looking for, the peak to peak vibration that you're looking for. You don't really have a heck of a lot of actual variability in there and control. It's almost like you're either off or you're on. And the best you can do is have that silly pulsing thing that the vibrating ones do, you know, where they go like, "Root, root, root," you know, that kind of a thing? Yeah. As opposed to the LRA, where you can actually accelerate at different rates. You can have because you've got more precise control, you can actually have shorter pulses that are closer together. So you can actually get like a tap, a tap, a tap, a tap, a tap, a tap, much closer together, like a machine gun going off, I guess. But anyway, and that intensity is variable. Hence on the watch, you can actually have prominent feedback. And even if it's not prominent feedback, you can actually have different levels. So you can have a, there's like an off completely obviously that's nothing. There's a middle like a medium and a high and then there's prominent which is I guess it's three different levels of haptic feedback. Anyway okay so that's pretty cool. Honestly I don't have much else to add about the reasons behind this and the math behind it. I think it's fascinating I think it's an interesting trade-off and for me it's been absolutely transformative for me because what I've done is I've just turned everything off, all my audio, and I rely solely on the Apple Watch tapping me with a Taptic Engine on a faintest possible tap for all of my notifications across the board. I've got a silent ringtone. I've just set everything to sound off, tap, tap, tap. That's it. And I love it because whenever I'm- Do you get the phantom taps on your wrist like you sometimes do with your leg when you think your phone's vibrating, but it's not? Not yet, not yet, but I suspect that it's a synaptic path that's going to start going in my brain and eventually that's probably inevitable. But for the moment at least, I'm enjoying the fact that that's not an issue. So yeah, maybe someday that will happen, Carmen, but let's hope it doesn't for a while because I'm enjoying it. And what I enjoy though is that I don't have that noise. I don't have the buzzing or anything like that. You know, my 6S Plus, I've actually turned off all of the vibration on it. I don't like the Taptic Engine on it because it makes noise. I can hear it. If it's sitting on my desk, I can hear it. I don't want that. I've got the Apple Watch for that. So I've turned it off. And some people might think that's crazy, but you know what? I don't need the Taptic Feedback on my phone going off because I can't adjust the Taptic Intensity on the 6S Plus based on my finger pressing. I can adjust the 3D Touch Pressure, but I can't adjust the Feedback. So it's one pressure sensing, pressure response, sorry. It's one tap response level for all of it. There's three levels on the watch and there's none. It's either on or off on the phone. So I turn it off and it's great because what it means is that I don't hear a thing. I just feel it through my wrist and someone else's phone can be going off in the other part of the building 'cause in the last 10 years, every phone ringtone you could imagine pretty much, even the prank ones, I've had on my phone. So there's a part of your brain that's like, oh, is that my phone ringing over there? Oh, no, it's not. And now I know it's not my phone. not my phone. Yeah well I know it's not my phone anymore because I know that if my phone is silent. I actually did, there's an article I should put a link in the show notes about Silent Journey. I posted on Tech Distortion a few months ago and it's all about how I use the Apple Watch if you're interested. But anyway. Okay so I just want to quickly wrap up. I haven't got too much more else to add. I just want to talk briefly about the Force Touch trackpad and the Magic Trackpad 2 which only just came out a few weeks ago. So both of these use a different design. The actual trackpad itself is sitting on four little, I suppose you'd call them metal spring flaps of a sort. Now they've got strain gauges on them, which is really not that exciting or revolutionary or interesting, but they also perform a partial suspension so that the actual trackpad surface itself is partially suspended above the Taptic unit. And what that means is that the Taptic unit inside underneath the trackpad is working against, more working against the mass of the trackpad glass and construction than it is the entire body of the MacBook, which makes perfect sense because why do you want to be trying to vibrate against the entire mass of a MacBook Pro that's going to be sitting on a desk anyway? If you've got an iPhone, you're holding it in your hand. you've got a watch, it's on your wrist. So you have to work against that. You have to work against the mass of the body that you're holding and that you're contained within. But when you're actually on something as big and as heavy, I mean, these MacBooks, I mean, the MacBook Air, the magic, okay. So the MacBook, the original MacBook it came out on was the 12-inch MacBook that was released in March this year. And it was on the MacBook Pro 13 inch on the same date, but the actual MacBook itself weighs 0.92 kilos. So that's 920 grams. pretty heavy and you would need a proportionally enormous Taptic Engine to move the whole thing. You don't need to move the whole thing, you just need to move the trackpad and that's what they're doing. So that's why the Taptic Engines in the touchpads are not in proportionally enormous because if you look at the difference in size between the Taptic Engine in the watch versus the Success, they're proportional in size whereas on the desktop they're not. And the Magic Trackpad 2 is no slouch, that thing is heavy, that's like 231 grams, that's 8.2 ounces. So again, it's a hefty bit of kit. It's funny when you think about it, the Magic Trackpad 2 is actually heavier than an iPhone 6s, despite the fact if you think about it, it has a heck of a lot less in it. Anyway, you don't have to put it in your pocket, mind you, can you fit a 6S+ in your pocket anyway. Cargo shorts man. Yeah well that's exactly right. Height of fashion right there. Yeah some people love them, I don't get it but that's okay. I'm not a fashion guy, I'm kind of the opposite on the spectrum. I don't wear cargo shorts too often but I wouldn't exactly say I'm fashionable. Oh there you go then. Anyway alright so honestly yeah, that's it really. I find that those are the reasons why I think that the Taptic technology is an excellent step forward. I think the reasons that Apple chose to do it to save energy, I think that the trade-offs that they made are good trade-offs. Even though they're making their products slightly heavier, it's a better experience overall. It gives them a far better control for more unique form of feedback. I honestly think that those are all wins. What's interesting though is why so many other companies haven't done this. If you think about it, the ERM technology has been around so long, it's cheap, it's been miniaturized and for most people it's good enough. But once you've used the Taptic stuff using the linear actuators, it's pretty hard to go back because the extra sensitivity and the extra control that you get and the sensation you get out of it, I can totally see why Apple have done it. And it's pretty clear to me that their tactic moving forward is to use this everywhere and that eventually ERMs will be gone and banished from all of Apple's equipment moving forward. So I would not be surprised to see Taptic feedback in all iPads as well and every model of MacBook and MacBook Pro and they've just added to the trackpad too, which when I started working on these notes a while ago, that was before they released it, but that was obviously next on their list and now they've done that. So I think it's pretty clear that where the future lies for Apple anyway. So anyway, there you go. What do you think? All right. Stick a fork in it. We're done. All right. You stick forks in things regularly. I mean, other than to eat things. I'm just saying. But anyway, I got a pocket fork, you know, just in case. Got to be prepared for anything. Okay. Fantastic. There you have it, everybody. Right, good. If you'd like to know more about this and, you know, portable forks that you'd take with you, you could reach me on Twitter @johnchidjee, but about the forks you'd want to reach Carmen. Anyway, sorry. Don't spoil episode 67, come on. What? Oh, Jack, yeah, where we talk about forks. No. Pocket camping tools. Okay. Eating on the go. Yes. And you could follow Pragmatic's show on Twitter specifically to see show announcements and other related stuff. Remember that Pragmatic is now part of the Engineered Network and it also has an account, engineered_net. It has show announcements about the network specifically and all of its shows. You can check it out at Now, of course, Carmen, if they want to get in touch with you, what's the best way for them to do that? They can get in touch with me on Twitter @FakeyEquips or on the Engineered Network webpage, send some feedback for the show. My picture is the one with the sawzall, I hope. I didn't follow through on my threat to change your... But I know, I'm sorry. That's all right, it's my Twitter picture now, so it's all good. Yeah, I did see that. Oh dear, anyway. So yeah, so obviously, yes, and as Carmen alluded to, if you'd like to send any feedback about the show or the network, then please use the feedback form on the website, and that's where you'll also find channels for this episode. I'd personally like to thank ManyTricks once again for sponsoring the Engineered Network. If you're looking for some Mac software that can do many tricks, remember specifically visit this URL, for more information about their amazingly useful apps. And finally, one last note, the network does have a Patreon account if you like what we're doing here at the Engineered Network and you'd like to contribute something, anything at all, it's very much appreciated and it helps to not only keep the existing shows going but to help us bring new shows to you and there's a few in the works right now so exciting stuff coming there are a few perks in there as well so check it out it all helps so thank you everyone for listening as always and thank you again Carmen all right thanks John and yeah thanks again for listening everyone (upbeat music) (upbeat music) (upbeat music) [Music] (upbeat music) (upbeat music) (upbeat music) (upbeat music) [MUSIC PLAYING] (upbeat music) [MUSIC] [Music] [BLANK_AUDIO]
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Carmen Parisi

Carmen Parisi

Carmen is an Electrical Engineer working as an Application Engineer in analogue electronics and has a blog Fake EE Quips that he occasionally posts to. Carmen is also a co-host on The Engineering Commons podcast.

John Chidgey

John Chidgey

John is an Electrical, Instrumentation and Control Systems Engineer, software developer, podcaster, vocal actor and runs TechDistortion and the Engineered Network. John is a Chartered Professional Engineer in both Electrical Engineering and Information, Telecommunications and Electronics Engineering (ITEE) and a semi-regular conference speaker.

John has produced and appeared on many podcasts including Pragmatic and Causality and is available for hire for Vocal Acting or advertising. He has experience and interest in HMI Design, Alarm Management, Cyber-security and Root Cause Analysis.

You can find him on the Fediverse and on Twitter.