WEBVTT - TechStuff Classic: TechStuff Gets Fit 0:00:04.400 --> 0:00:07.760 Welcome to tex Stuff, a production from I Heart Radio. 0:00:12.000 --> 0:00:14.760 Hey there, and welcome to tech Stuff. I'm your host, 0:00:14.920 --> 0:00:17.840 Jonathan Strickland. I'm an executive producer with I Heart Radio 0:00:17.920 --> 0:00:21.320 and I love all things tech. It's time for another 0:00:21.440 --> 0:00:25.360 classic episode. This one is titled tech Stuff Gets Fit. 0:00:25.520 --> 0:00:28.960 It's all about activity trackers. Back then, I think I 0:00:29.040 --> 0:00:32.640 was just starting to use them. And this episode originally 0:00:32.680 --> 0:00:37.839 published on May two thirt enjoy. We want to talk 0:00:37.840 --> 0:00:41.159 about what these devices are, what they do, how they 0:00:41.200 --> 0:00:43.920 do it, and whether or not they're actually effective if 0:00:43.920 --> 0:00:47.000 you want to do something like lose weight or get fit. Yeah. 0:00:47.120 --> 0:00:48.600 Just I mean, you know, not that that many people 0:00:48.640 --> 0:00:50.880 are interested in that kind of thing. Yeah, you know, yeah, 0:00:50.880 --> 0:00:53.560 there's just like maybe two right, Okay, So the last 0:00:53.600 --> 0:00:55.800 few times I've gone to C E S I have 0:00:55.960 --> 0:00:57.880 noticed it really was I think it was two years 0:00:57.880 --> 0:01:03.040 ago where that it was dramatically apparent that fitness tracking 0:01:03.040 --> 0:01:05.360 and activity tracking is a real thing. I mean, it's 0:01:05.400 --> 0:01:08.000 it's huge, huge, booming industry. Yeah. Well, I mean, you know, 0:01:08.080 --> 0:01:12.800 as as between circuitry getting smaller and uh sinking, technology 0:01:12.840 --> 0:01:15.880 improving and the software improving and just all of these 0:01:15.920 --> 0:01:20.160 things have been coming together to create these smaller, sleeker, 0:01:20.520 --> 0:01:23.520 you know, better devices that can really help people out 0:01:23.560 --> 0:01:27.360 things that are things like interoperability to where it can 0:01:27.400 --> 0:01:31.720 interact with computers or smartphones. Not not every device does that. 0:01:32.520 --> 0:01:34.040 Let's be clear about that. There are a lot of 0:01:34.040 --> 0:01:37.240 devices out there that have kind of a limited use 0:01:37.400 --> 0:01:39.160 like that. Maybe they just sink with a computer, or 0:01:39.200 --> 0:01:41.399 maybe it's just a standalone device, but a lot of 0:01:41.440 --> 0:01:44.760 them do sync up with more than one device. You 0:01:44.760 --> 0:01:47.600 can do it with a smartphone application or or a 0:01:47.640 --> 0:01:50.040 computer or other things as well, and they'll let you. 0:01:50.040 --> 0:01:53.200 They'll let you port port whatever data you record into 0:01:53.240 --> 0:01:55.680 different apps, so that if for example, you're into this 0:01:55.760 --> 0:01:57.720 kind of thing and you have a favorite app, you 0:01:57.760 --> 0:02:00.240 can you can use that one to crunch your numbers 0:02:00.360 --> 0:02:03.840 rather than whatever other proprietary thing they have created. Right, right, 0:02:03.880 --> 0:02:06.600 So this gives you a chance to, uh, to really 0:02:07.120 --> 0:02:09.280 keep a good look, you know, get a really good 0:02:09.280 --> 0:02:13.200 look at how much activity you are you have throughout 0:02:13.240 --> 0:02:15.480 a given amount of time, like a week or a day. 0:02:15.560 --> 0:02:17.760 So you might say, all right, I want to set 0:02:17.800 --> 0:02:21.200 a goal for myself and this device will help me 0:02:21.200 --> 0:02:23.880 measure up against that goal and decide, you know, am 0:02:23.880 --> 0:02:26.120 I am I meeting my goal. Do I need to 0:02:26.560 --> 0:02:28.520 uh to crank up the activity. Do I need to 0:02:28.560 --> 0:02:31.920 maybe you know, do a three mile jog in the 0:02:31.960 --> 0:02:33.920 morning in order to hit what my goals are? Do 0:02:34.000 --> 0:02:37.720 I need to um to scale back? Or for for 0:02:37.720 --> 0:02:40.880 for hardcore trainers, am I running my heart rate too hard? Yeah? Yeah, 0:02:40.960 --> 0:02:43.800 So it all depends on what device you have, whether 0:02:43.880 --> 0:02:46.120 or not you can actually do these things, because, like 0:02:46.120 --> 0:02:50.920 we said, not every device does everything. In fact, depending 0:02:50.960 --> 0:02:53.120 upon what you want, that's going to really guide your 0:02:53.200 --> 0:02:56.040 choices when it comes to picking an activity tracker. If 0:02:56.120 --> 0:02:58.880 you're interested in something like that, absolutely, and there's there's 0:02:58.880 --> 0:03:01.200 a lot of really terrific reviews out there on the internet. 0:03:01.320 --> 0:03:04.200 We'll mention at least one good site to go to 0:03:04.360 --> 0:03:07.200 later on in the podcast. Yeah, there's I came across 0:03:07.320 --> 0:03:09.440 lots and lots of them. And it's interesting too because 0:03:09.480 --> 0:03:13.400 you can see where the different preferences come into play, 0:03:13.440 --> 0:03:16.880 because one reviewer might say, well, you know, X is 0:03:16.919 --> 0:03:20.480 the best activity tracker because it does things this way, 0:03:20.560 --> 0:03:22.120 and someone else to say, no, no no, no, why is 0:03:22.120 --> 0:03:24.359 the best activity tracker because it does things in this 0:03:24.440 --> 0:03:26.920 other way? And it's just because it appeals to that 0:03:26.960 --> 0:03:31.120 particular person a very personal choice. Right So, so that's 0:03:31.160 --> 0:03:32.880 one thing you can get you can walk away with 0:03:33.080 --> 0:03:34.840 right now, is that we're not gonna at the end 0:03:34.840 --> 0:03:36.840 of this podcast. It's not like we're gonna say the 0:03:36.880 --> 0:03:39.880 best activity tracker is blah blah blah, because it all 0:03:39.960 --> 0:03:43.320 depends on what you want to get out of it now. Frankly, 0:03:43.440 --> 0:03:45.680 I think if you are looking at one of these things, 0:03:45.760 --> 0:03:47.119 the thing you really want to get out of it 0:03:47.240 --> 0:03:50.680 is is making sure that you are living a healthy lifestyle. 0:03:51.680 --> 0:03:53.600 And most of the ones that are on the market 0:03:53.720 --> 0:03:56.800 right now will help you do that depending on how 0:03:56.920 --> 0:03:59.440 you use it. It's it's not a magic device that 0:03:59.520 --> 0:04:04.080 automatic turns you into a fit pro athlete right now. Now. 0:04:04.120 --> 0:04:05.320 You have to you have to have your own a 0:04:05.360 --> 0:04:09.680 personal sense of motivation about exercising first. Probably obtaining a 0:04:09.680 --> 0:04:12.000 fitness tracker is going to be one of the steps 0:04:12.040 --> 0:04:15.360 that you're you know, carrying out in this motivation UM 0:04:15.440 --> 0:04:19.159 and and study studies have shown um that that that 0:04:19.320 --> 0:04:21.960 just mindfulness about this kind of thing can really help 0:04:22.000 --> 0:04:26.520 you out from lots lots of different corners of health 0:04:26.560 --> 0:04:29.600 and fitness. When when you are given the power to 0:04:30.440 --> 0:04:32.720 track your own data and to kind of take it 0:04:32.760 --> 0:04:34.680 into your own hands like that, maybe gamify at a 0:04:34.680 --> 0:04:38.640 tiny bit you it really helps you out right. There's 0:04:38.720 --> 0:04:42.280 an expert. Her name's Dina Bravada. I'm sure you ran 0:04:42.320 --> 0:04:45.360 across her name several times as well, because it's all 0:04:45.360 --> 0:04:49.880 over the place in the research on activity tracking, and 0:04:50.200 --> 0:04:53.599 she has said that there there is a bit of 0:04:53.600 --> 0:04:57.279 a bias that's present with activity trackers in the sense 0:04:57.360 --> 0:05:00.760 of the people who are interested in them. She says 0:05:00.800 --> 0:05:03.760 that here's a quote. Often those kind of programs have 0:05:03.800 --> 0:05:07.600 been criticized because they attract people who are already physically active. 0:05:07.920 --> 0:05:10.240 In general, there are two categories of people who use 0:05:10.320 --> 0:05:12.640 these trackers, those who are told to wear them by 0:05:12.680 --> 0:05:15.640 a doctor because of an underlying health problem and those 0:05:15.640 --> 0:05:17.800 who are really active and just get a kick out 0:05:17.800 --> 0:05:21.479 of knowing their data. Now, none of that is a 0:05:21.839 --> 0:05:25.080 smack against these activity trackers and whether or not they 0:05:25.160 --> 0:05:28.280 are effective in what they do. She is simply saying 0:05:28.279 --> 0:05:30.920 that this is the person side of that equation, not 0:05:31.040 --> 0:05:34.200 the technology side of that equation. So let's assume that 0:05:34.279 --> 0:05:36.360 at least some of you guys out there listening are 0:05:36.839 --> 0:05:39.960 very much interested in this kind of stuff, and you 0:05:40.040 --> 0:05:42.480 are either interested in just knowing how they work in general, 0:05:42.600 --> 0:05:44.520 or you're actually thinking, hey, I would kind of like 0:05:44.680 --> 0:05:48.839 to look into one of these. How do they track activity? 0:05:49.279 --> 0:05:52.720 What exactly is being tracked? And what other features might 0:05:52.760 --> 0:05:54.800 I be interested in if I want to get one 0:05:54.839 --> 0:05:57.320 of these things myself. So I thought we'd talk a 0:05:57.320 --> 0:06:00.919 little bit about some of the basic technology cheese that 0:06:01.040 --> 0:06:04.560 you find inside some of these trackers, right, because these 0:06:04.560 --> 0:06:08.800 little these little bitty watch sized or bracelet sized or 0:06:09.320 --> 0:06:12.080 clips clips. You know, you have very very small devices 0:06:12.120 --> 0:06:16.719 these days. You can pack a lot of tracking devices 0:06:16.800 --> 0:06:20.200 into them. Yeah, the sensors that are available now really 0:06:20.240 --> 0:06:22.360 boggle the mind. And like we said, I don't think 0:06:22.360 --> 0:06:24.400 there is a device out there that has every single 0:06:24.520 --> 0:06:26.360 version of what we're about to talk about. But I 0:06:26.680 --> 0:06:29.440 have not seen one. Yeah, but many of them have several, 0:06:29.480 --> 0:06:32.040 some of them only have one or two some And 0:06:32.560 --> 0:06:34.520 it may be that the way that they're packaged is 0:06:34.640 --> 0:06:38.080 very attractive, but they but from a technological point of view, 0:06:38.360 --> 0:06:43.479 they are comparatively simple. But I think one very basic 0:06:43.640 --> 0:06:46.599 technology we can talk about that you can find, and 0:06:46.640 --> 0:06:48.520 in fact, some people will argue that this is really 0:06:48.560 --> 0:06:50.280 all you need if you just want to track some 0:06:50.360 --> 0:06:53.680 basic activity is a predometer, right, and these have been 0:06:53.880 --> 0:06:56.960 mechanical predometers. I believe it's been around since the nineteen sixties, 0:06:57.279 --> 0:07:01.760 and they hypothetically this is this is tenuous, tenuous reportage. 0:07:01.800 --> 0:07:04.039 But but some people say that the da Vinci or 0:07:04.080 --> 0:07:07.840 Thomas Jefferson came up with the idea many many moons ago. Yeah, 0:07:07.960 --> 0:07:11.200 that's a pretty big spread in years, if I know 0:07:11.320 --> 0:07:15.280 my history. But yeah, and I do. But yeah, a 0:07:15.280 --> 0:07:19.720 podometer today it takes a pretty basic form. Usually you 0:07:19.800 --> 0:07:22.160 have some sort of display that's going to tell you 0:07:22.200 --> 0:07:24.880 how many steps you have taken. That's what a podometer does. 0:07:24.880 --> 0:07:27.000 It's supposed to measure how many steps you take. So 0:07:27.040 --> 0:07:30.440 how does it do that. It's essentially counting the number 0:07:30.440 --> 0:07:33.520 of times your foot makes impact with the ground. And 0:07:33.800 --> 0:07:37.640 really that means it's just measuring various shaking of your body. 0:07:37.720 --> 0:07:40.400 So if you are in a car and you're on 0:07:40.440 --> 0:07:43.160 a pathicularly bumpy road, it's going to start registering that 0:07:43.240 --> 0:07:47.240 as footsteps if it's particularly bumpy, right, or or if 0:07:47.240 --> 0:07:48.960 you hold it in your hand and sway your arm 0:07:49.000 --> 0:07:51.560 back and forth, you would totally fool the device, right, 0:07:51.600 --> 0:07:54.960 Not that I know that from prior get fit corporate 0:07:55.200 --> 0:07:57.840 um programs that I have cheated a tiny bit on. Right, 0:07:58.840 --> 0:08:01.520 If you're not benefiting any one at that point, let's 0:08:01.600 --> 0:08:05.040 let's stop the cheating. Hey, Lauren, aren't you the team 0:08:05.120 --> 0:08:10.320 captain of our own departmental cheating. I was demonstrating to 0:08:10.400 --> 0:08:13.400 people how the device worked, and I was accused of 0:08:13.920 --> 0:08:17.840 using that as a way of boosting your numbers. All right, 0:08:17.880 --> 0:08:19.760 team captain, Now I've learned a little more about you. 0:08:19.880 --> 0:08:23.120 So anyway, what's what's going on here is inside the 0:08:23.120 --> 0:08:27.800 pedometer you have a system that essentially forms a switch. 0:08:28.120 --> 0:08:30.720 All right, You've got you've got a weight, and when 0:08:30.720 --> 0:08:34.960 that weight moves it can make a connection that closes 0:08:35.000 --> 0:08:37.360 a switch and counts as a step. And then when 0:08:37.360 --> 0:08:40.560 it moves away that and hits it again, that counts 0:08:40.600 --> 0:08:43.720 as another step. So every time this weight disconnects and 0:08:43.720 --> 0:08:49.160 then reconnects with a contact, a step is registered. And uh, 0:08:49.360 --> 0:08:50.880 you know, it used to be that these were pretty 0:08:50.880 --> 0:08:53.760 big mechanical things where you had a weight suspended on 0:08:54.120 --> 0:08:57.120 like a spring or a pendulum or a small ball 0:08:57.200 --> 0:08:59.240 that could roll back and forth across a tiny track. 0:08:59.440 --> 0:09:02.280 Right now, we're talking about things that are on the 0:09:02.280 --> 0:09:06.600 the micro structure level. But it's still this basic mechanical 0:09:06.679 --> 0:09:10.720 motion of making a contact breaking a contact, and that 0:09:10.840 --> 0:09:12.839 every time you do that break is what counts is 0:09:12.880 --> 0:09:16.080 a step. Yeah, so uh, it's still still the same 0:09:16.120 --> 0:09:19.640 mechanical approach. It's just now it's much much, much, much 0:09:19.679 --> 0:09:22.080 smaller than what it used to be back in the 0:09:22.120 --> 0:09:26.720 sixties or earlier. If we are to believe that some 0:09:26.840 --> 0:09:30.679 of our our genius ancestors came up with this idea, 0:09:30.800 --> 0:09:34.160 it was probably Tesla, yeah, and it always ends up 0:09:34.200 --> 0:09:37.679 being Tesla, although his probably would also bring down an airplane. 0:09:38.120 --> 0:09:41.960 So uh. Anyway, the old predometers, if you would actually 0:09:42.000 --> 0:09:43.440 pick one up and shake it, you might hear a 0:09:43.440 --> 0:09:46.720 clicking noise, and that's the little switch that's inside it. Again, 0:09:46.720 --> 0:09:48.800 it might be that little ball if it's using that 0:09:48.840 --> 0:09:52.679 particular kind of technology. The newer ones, again are all 0:09:52.760 --> 0:09:55.640 chet based. They don't have those little those. They don't 0:09:55.679 --> 0:09:57.920 have things large enough to make that kind of clicking 0:09:57.960 --> 0:10:00.600 noise unless you've been shaking it way too hard, in 0:10:00.640 --> 0:10:02.680 which case something is probably loose and it may not 0:10:02.760 --> 0:10:06.360 be working at all anymore. But anyway, that's your very 0:10:06.360 --> 0:10:10.760 basic pedometer, so it's not terribly accurate. In the sense 0:10:10.840 --> 0:10:14.920 that it can't it can't distinguish between different kinds of 0:10:14.960 --> 0:10:17.120 impact and say, oh, well that was definitely a step 0:10:17.240 --> 0:10:20.320 versus that was just a bump, right. Um. But they 0:10:20.720 --> 0:10:23.520 are getting a little bit more technologically advanced in that. 0:10:23.559 --> 0:10:27.280 Originally you had to use the counter and combine that 0:10:27.360 --> 0:10:29.800 with a calculation of how long each of your steps 0:10:29.800 --> 0:10:31.960 were in order to calculate distance. These days, they can 0:10:32.000 --> 0:10:34.719 do that for you with onboard computers. Sure. Oh so 0:10:34.760 --> 0:10:37.480 instead of saying like, oh, my stride is this many 0:10:37.520 --> 0:10:40.600 inches long, therefore this many steps and having to get 0:10:40.600 --> 0:10:42.480 a little bit of math. Right by the way, I 0:10:42.480 --> 0:10:45.520 said inches, and I would say miles because I live 0:10:45.559 --> 0:10:48.200 in America and that's what we do. But centimeters meters 0:10:48.240 --> 0:10:50.800 that kind of thing, right, it would It does the 0:10:50.840 --> 0:10:54.760 math depending on what scale you're using. The more advanced 0:10:54.880 --> 0:11:00.080 version of this sort of approach is the accelerometer. Right now, 0:11:00.120 --> 0:11:02.760 an accelerometer is different. It's not got a little switch 0:11:02.880 --> 0:11:08.080 that's just registering a change. Yeah, it's not just like 0:11:08.480 --> 0:11:13.320 that was a shake. It's actually detecting changes in velocity. Uh. Now, 0:11:13.400 --> 0:11:18.719 velocity is speed plus direction, So if you alter that velocity, 0:11:18.840 --> 0:11:23.280 then you are talking about an accelerating force. So, for example, 0:11:23.280 --> 0:11:26.080 when you start, when you start from a standstill and 0:11:26.120 --> 0:11:30.199 you start moving into a run, that's accelerating. You're accelerating 0:11:30.200 --> 0:11:32.000 into a run. Now, once you hit top speed, you 0:11:32.080 --> 0:11:34.440 are no longer accelerating. You may be maintaining a speed. 0:11:34.800 --> 0:11:39.120 But accelera arometers are all meant to detect these changes 0:11:39.160 --> 0:11:43.360 in velocity. And you've got two basic categories of accelerometers. 0:11:43.400 --> 0:11:45.920 There are many types of accelerometer rometers, but they fall 0:11:45.920 --> 0:11:50.280 into two basic categories. They're static accelerometers. Now, these measure 0:11:50.360 --> 0:11:57.319 a static uh form of acceleration. For instance, gravity. Gravity 0:11:57.600 --> 0:12:01.360 is static, it's not change when you are on the 0:12:01.360 --> 0:12:03.520 surface of the Earth. It's going to remain the same. 0:12:03.960 --> 0:12:07.920 And so you might wonder why would you need a 0:12:07.920 --> 0:12:12.280 stack accelerometer. It's so that you can determine the rotation 0:12:12.480 --> 0:12:15.200 of a device in respect to the surface of the Earth. 0:12:15.559 --> 0:12:18.880 Very important for something like a smartphone. Where you are 0:12:18.880 --> 0:12:21.000 holding the smartphone, you move it from portrait to landscape, 0:12:21.840 --> 0:12:26.240 the static accelerometer is what tells it, oh, the the 0:12:27.320 --> 0:12:30.439 attitude of this phone has changed, not that you're giving 0:12:30.480 --> 0:12:34.560 off attitude necessarily. You might be texting I usually am 0:12:34.600 --> 0:12:37.960 this is fair, but rather the position in relative to 0:12:38.000 --> 0:12:39.480 the surface of the earth. So if you were to 0:12:39.559 --> 0:12:43.480 turn it into the landscape mode, the screen would would 0:12:43.559 --> 0:12:48.880 change to reflect that. That's why a stack accelerometer is useful. 0:12:48.880 --> 0:12:53.360 For dynamic accelerometers, they measure changes in motion of the 0:12:53.360 --> 0:12:57.000 accelerometer itself, so the accelerometer is part of the larger device. 0:12:57.480 --> 0:13:00.360 So this is to measure the changes in accel oration 0:13:00.520 --> 0:13:02.680 of that device, not in respect to the ground, but 0:13:02.800 --> 0:13:06.560 just within that device itself. So you might have both 0:13:06.600 --> 0:13:09.959 types in a fitness tracker. If the fitness tracker has 0:13:10.000 --> 0:13:12.559 some sort of screen that will rotate depending upon how 0:13:12.600 --> 0:13:15.280 you're holding your arm. Let's say it's a it's a 0:13:15.400 --> 0:13:18.000 screen that's on a wristband or something that's like a watch, 0:13:18.800 --> 0:13:20.800 and then it might have a stack accelerometer and a 0:13:20.880 --> 0:13:23.880 dynamic one. The dynamic one would be more useful for 0:13:23.960 --> 0:13:27.920 it to detect changes in velocity and thus translate that 0:13:28.080 --> 0:13:32.800 into motion that the user is moving around and that 0:13:32.840 --> 0:13:36.560 means that the user is burning calories and is there's 0:13:36.679 --> 0:13:39.760 there's activity going on, So that's part of the data 0:13:39.840 --> 0:13:44.920 that this device will gather and analyze to translate that 0:13:44.960 --> 0:13:47.880 into This is what your body is doing right right, 0:13:47.920 --> 0:13:49.560 and we should we should add at this point that 0:13:49.960 --> 0:13:53.560 that a lot of the actual output of data that 0:13:53.679 --> 0:13:56.680 these devices are giving you is not UM. Is not 0:13:56.720 --> 0:13:58.880 the actual data that these sensors are taking in a 0:13:58.880 --> 0:14:02.600 lot of it is UM really fancy algorithms. And and 0:14:02.640 --> 0:14:04.680 thank you to Peter on Facebook for writing in and 0:14:04.720 --> 0:14:06.920 telling me that I totally say that wrong sometimes because 0:14:06.960 --> 0:14:10.360 I do UM. You know, it's it's it's approximating more 0:14:10.440 --> 0:14:14.320 complex technology, or it's gathering together a bunch of these 0:14:14.640 --> 0:14:18.240 little tiny numbers and figuring out something useful that I 0:14:18.280 --> 0:14:21.280 can tell you in return, exactly taking this raw data 0:14:21.320 --> 0:14:24.320 and making it meaningful to us, because otherwise we really 0:14:24.360 --> 0:14:27.000 what an accelerometer would tell you is how much voltage 0:14:27.200 --> 0:14:29.680 it was generating, which doesn't help us at all. That 0:14:29.720 --> 0:14:32.760 doesn't that's not meaningful to at least it's not meaningful 0:14:32.760 --> 0:14:35.800 to me, and I suspect not to Lauren. Uh. Some 0:14:35.920 --> 0:14:38.680 of you electricians out there might say, no, I totally 0:14:38.680 --> 0:14:40.560 get it, but the rest of us are thinking, no, 0:14:40.640 --> 0:14:42.840 we need this translated into something that makes sense, like 0:14:42.880 --> 0:14:44.840 how many calories did I burn or how many steps 0:14:44.840 --> 0:14:47.480 did I take? Or how far did I go? So 0:14:47.560 --> 0:14:53.280 that's that's the basic uh two kinds of accelerometers. The 0:14:53.280 --> 0:14:57.960 the types underneath those are how they detect these changes 0:14:58.000 --> 0:15:00.960 in velocity. UH. And there's a lot there's there are 0:15:01.000 --> 0:15:05.080 capacitive ones, there's piece of electric, there's piezo resistive, there's 0:15:05.120 --> 0:15:09.360 magneto resistive, there's heat transfer. There's lots of different types. 0:15:09.400 --> 0:15:12.360 There's some that use light. But the one that I think, 0:15:12.720 --> 0:15:15.040 the type that's used the most in electronics as far 0:15:15.080 --> 0:15:18.400 as I can tell, is the capacity of type. And 0:15:18.480 --> 0:15:21.160 so you might wonder how does this work. You've got 0:15:21.280 --> 0:15:25.480 some micro structures within a chip, all right. One of 0:15:25.480 --> 0:15:29.560 them is you've got a housing which is mounted directly 0:15:29.600 --> 0:15:33.320 to whatever the devices on a substrate. So this housing 0:15:34.000 --> 0:15:37.520 will move in uh, the same way that the device 0:15:37.520 --> 0:15:41.880 itself moves. It's it's dependent upon that. Then you've got 0:15:41.920 --> 0:15:47.120 a little micro structure inside of it that can move freely, 0:15:47.800 --> 0:15:51.520 uh in respect to the housing. So if you were 0:15:51.520 --> 0:15:54.320 to shake the device, the micro structure would lag a 0:15:54.400 --> 0:15:56.680 little bit and then pick up that motion, just as 0:15:56.680 --> 0:15:58.800 if you had a spring with the ball on the 0:15:58.880 --> 0:16:00.600 end and you started moving the top of the spring 0:16:00.600 --> 0:16:01.920 and then the ball would start to move. It's this 0:16:01.920 --> 0:16:04.680 whole momentum thing that's coming up. You've also got these 0:16:04.720 --> 0:16:07.800 other little bitty structures, these micro structures inside this this 0:16:07.880 --> 0:16:10.840 tiny little chip, and I'm talking about teeny tiny. We're 0:16:10.920 --> 0:16:14.080 we're tug on the level of microns, right. These are 0:16:14.080 --> 0:16:17.200 all called a microelectro mechanical systems. Yeah, they're they're so 0:16:17.240 --> 0:16:19.800 small that you have to have an automated system to 0:16:19.960 --> 0:16:23.440 etch them onto chips because there's no human with the 0:16:23.440 --> 0:16:28.360 precision necessary to make these things so super tiny. But 0:16:28.800 --> 0:16:31.560 as the microstructure moves, it starts to move between these 0:16:31.600 --> 0:16:34.880 plates that have capacitance. That changes the capacities. It causes 0:16:34.920 --> 0:16:38.000 current to flow, and measuring the current tells you how 0:16:38.080 --> 0:16:41.840 much this device is moving. And by putting these chips 0:16:41.920 --> 0:16:45.600 in different arrangements within a device, you can track different 0:16:45.680 --> 0:16:48.920 types of movement because you can only detect movement along 0:16:48.960 --> 0:16:52.760 one axis with it with a very simple accelerometer. That 0:16:52.840 --> 0:16:57.120 means that you can detect movement along one line of 0:16:57.480 --> 0:17:00.760 one one vector. Really you can't anything beyond that. It 0:17:00.760 --> 0:17:04.240 wouldn't detect. So let's say left right versus up down. 0:17:04.880 --> 0:17:07.640 If you had three of these accelerometers or to two 0:17:07.680 --> 0:17:10.960 axis accelerometers that were at right angles to one another. 0:17:11.240 --> 0:17:13.639 You could then detect things like along the x axis, 0:17:13.680 --> 0:17:16.640 the y axis, and the z axis. So three axis 0:17:16.640 --> 0:17:19.479 accelerometers what we call those, and those are that those 0:17:19.520 --> 0:17:21.040 are the popular ones and in all of the new 0:17:21.080 --> 0:17:22.920 devices coming out these days. Yeah, and it's also the 0:17:23.000 --> 0:17:25.320 kind of stuff you find in things like video game controllers. 0:17:25.760 --> 0:17:27.360 Uh and it's you know, some of them. You hear 0:17:27.359 --> 0:17:30.480 about six axis, which is really just getting more specimilar, 0:17:30.920 --> 0:17:33.800 more precise. Um. Yeah, And so this will detect those 0:17:33.880 --> 0:17:37.080 changes in motion and be able to translate that into 0:17:37.160 --> 0:17:40.640 again meaningful data once you run those raw numbers through 0:17:40.720 --> 0:17:44.480 whatever software you've got. Uh. So those are your two 0:17:44.760 --> 0:17:49.679 basic ways of detecting motion from a purely like this 0:17:49.800 --> 0:17:52.120 device is moving kind of perspective. There are other things 0:17:52.160 --> 0:17:55.080 that will also detect motion, which we'll talk about as 0:17:55.080 --> 0:17:57.200 well in a little bit. Before I get to that, though, 0:17:57.240 --> 0:17:58.680 I do need to say there's a couple other things 0:17:58.680 --> 0:18:01.720 that are important about accelerometer. One is that sensitivity of 0:18:01.720 --> 0:18:06.840 an accelerometer is extremely important. The more sensitive and accelerometer is, 0:18:07.240 --> 0:18:11.359 then the more it will generate a larger charge in 0:18:11.440 --> 0:18:14.440 our larger change in signal rather for a given change 0:18:14.440 --> 0:18:19.120 and acceleration compared to a less sensitive chip. So these 0:18:19.160 --> 0:18:22.000 bigger changes are easier to measure, and that gives the 0:18:22.040 --> 0:18:25.639 device a better idea of the actual changes in acceleration. So, 0:18:25.960 --> 0:18:28.280 in other words, if you if you make it so 0:18:28.320 --> 0:18:31.440 that these changes are are huge, uh, it can really 0:18:31.560 --> 0:18:34.439 narrow down the parameters of what that change means, and 0:18:34.480 --> 0:18:38.359 it can be more precise in thinking this is more 0:18:38.520 --> 0:18:42.440 likely an actual step versus something just bump their knee 0:18:42.480 --> 0:18:45.000 on their desk and went out, Yeah, yeah, the technology 0:18:45.040 --> 0:18:46.960 is getting a lot better at um weeding out those 0:18:46.960 --> 0:18:49.719 false positives exactly. And then there are other things you've 0:18:49.720 --> 0:18:52.520 got to keep in mind, like what's the maximum swing 0:18:52.800 --> 0:18:56.399 of your accelerometer that's telling you how much force it 0:18:56.480 --> 0:18:58.800 can measure or how much of a change in acceleration 0:18:58.800 --> 0:19:01.320 it can measure. Uh. This is really more important if 0:19:01.359 --> 0:19:04.399 you are designing something that moves really really fast and 0:19:04.440 --> 0:19:07.760 comes to really fast stops, like a jet, not so 0:19:07.880 --> 0:19:10.200 much with a person, because while you feel you might 0:19:10.240 --> 0:19:13.640 be fast compared to other stuff, you're really slow less 0:19:13.760 --> 0:19:16.000 less fast in the jet. And then you have bandwidth, 0:19:16.040 --> 0:19:18.000 which is how many times a second you can take 0:19:18.000 --> 0:19:21.840 a reliable acceleration reading. Uh, and we don't need anything 0:19:21.920 --> 0:19:25.000 too precise for human activity because again, we're not moving 0:19:25.080 --> 0:19:27.399 that quickly. But these are things that are important in 0:19:27.440 --> 0:19:31.520 accelerometers in general. Guys, we gotta take a quick break 0:19:31.560 --> 0:19:33.440 from this classic episode so I can get some more 0:19:33.480 --> 0:19:44.159 steps in, but we'll be right back. All right, we're back. So, 0:19:44.160 --> 0:19:46.760 so we've talked about accelerometers and presometers, there is one 0:19:46.800 --> 0:19:49.040 other way the device can track whether or not you've 0:19:49.080 --> 0:19:52.840 moved around, right, Because accelerometers are really great. Fear for example, 0:19:52.840 --> 0:19:56.240 on a treadmill, Yeah, fantastic because it doesn't have to 0:19:56.280 --> 0:19:59.119 track your location. It just has to track what you 0:19:59.240 --> 0:20:01.960 are doing. But if you have a GPS receiver in 0:20:02.000 --> 0:20:04.960 your activity tracker, and some of them do with them, 0:20:05.320 --> 0:20:09.320 you can actually track where you are in relation to 0:20:09.560 --> 0:20:11.840 I don't know anything else on the planet. But these 0:20:11.880 --> 0:20:14.840 are not so useful if you're just running on a treadmill. No, 0:20:14.960 --> 0:20:17.679 but but they are very much more accurate for calculating 0:20:17.760 --> 0:20:21.240 the distance that you have gone. Right. Yeah, So GPS 0:20:21.280 --> 0:20:24.880 in general, this Global Positioning system, Uh, what what's going 0:20:24.880 --> 0:20:27.200 on is You've got the satellites that are beaming down 0:20:27.200 --> 0:20:30.000 information here to the planet and network of twenty four 0:20:30.040 --> 0:20:34.880 of them. Yeah, so your GPS receiver receives this these 0:20:34.920 --> 0:20:38.639 signals from the various satellites. Now, each satellite is sending 0:20:38.680 --> 0:20:41.600 its own unique signal down that has essentially a time 0:20:41.680 --> 0:20:44.639 stamp on it, right, and they're all synchronized, right, So 0:20:44.680 --> 0:20:47.480 you're getting these different signals all at the same time 0:20:47.560 --> 0:20:52.240 from at least usually at least three satellites. Four works best, 0:20:52.320 --> 0:20:55.119 four works best, and and so your device gets these 0:20:55.160 --> 0:20:58.480 different signals from these different satellites. And by measuring how 0:20:58.520 --> 0:21:01.440 long it took the signal from each satellite to get 0:21:01.480 --> 0:21:05.080 to that uh, that device it just compares that against 0:21:05.119 --> 0:21:09.400 its own its own little internal clock. It can tell 0:21:09.480 --> 0:21:11.120 you where you are in the surface of the Earth. 0:21:11.160 --> 0:21:13.840 Technically you could be in one of two places, but 0:21:13.920 --> 0:21:17.000 that second places inside the Earth. So we pretty much 0:21:17.080 --> 0:21:21.040 just say that's not yea, it cuts that right out. Yeah, 0:21:21.119 --> 0:21:25.080 And this was originally military technology, I believe in the seventies, 0:21:25.800 --> 0:21:28.080 in the eighties and nineties. In fact, when when we 0:21:28.119 --> 0:21:34.800 first started getting consumer access to the Global Positioning System, Uh, 0:21:35.520 --> 0:21:39.760 the accuracy of that system for consumers was limited on purpose, right, Yeah, 0:21:39.840 --> 0:21:42.560 They they put limitters into the devices to say like, yeah, 0:21:42.640 --> 0:21:44.280 we don't really want you to know this thing. We 0:21:44.320 --> 0:21:49.880