WEBVTT 1 00:00:00.000 --> 00:00:01.020 In this lesson, 2 00:00:01.020 --> 00:00:03.660 we are going to talk about mobile device components. 3 00:00:03.660 --> 00:00:06.480 Specifically, we're going to be talking about digitizers, 4 00:00:06.480 --> 00:00:09.150 accelerometers, and gyroscopes. 5 00:00:09.150 --> 00:00:11.250 First, we have a digitizer. 6 00:00:11.250 --> 00:00:14.040 A digitizer is a layer sandwiched between a layer 7 00:00:14.040 --> 00:00:16.320 of protective glass and the display panel, 8 00:00:16.320 --> 00:00:18.480 inside of a touchscreen display. 9 00:00:18.480 --> 00:00:20.820 This digitizer is going to be able to convert 10 00:00:20.820 --> 00:00:22.320 the analog touch input 11 00:00:22.320 --> 00:00:23.940 to the digital software instructions 12 00:00:23.940 --> 00:00:25.890 that are used by the underlying applications 13 00:00:25.890 --> 00:00:27.630 and operating system. 14 00:00:27.630 --> 00:00:30.360 Anytime you touch your display on a smartphone or tablet, 15 00:00:30.360 --> 00:00:33.390 you're using the digitizer to send those inputs. 16 00:00:33.390 --> 00:00:35.190 Digitizers come as both capacitive 17 00:00:35.190 --> 00:00:37.320 and multitouch variants that will allow you 18 00:00:37.320 --> 00:00:39.630 to use either one finger or multiple fingers 19 00:00:39.630 --> 00:00:41.790 to be able to send commands to that display 20 00:00:41.790 --> 00:00:43.530 using the digitizer. 21 00:00:43.530 --> 00:00:45.510 In addition to the touch capability, 22 00:00:45.510 --> 00:00:47.610 a lot of these digitizers and screens 23 00:00:47.610 --> 00:00:49.950 also provide a way to provide haptic feedback 24 00:00:49.950 --> 00:00:51.210 to the end user. 25 00:00:51.210 --> 00:00:53.160 For example, on my iPhone, 26 00:00:53.160 --> 00:00:55.380 when I use the keyboard on the screen, 27 00:00:55.380 --> 00:00:57.210 it actually gives me a little vibration 28 00:00:57.210 --> 00:00:58.740 to let me know that I've actually touched 29 00:00:58.740 --> 00:01:01.530 that particular key as I'm typing out things. 30 00:01:01.530 --> 00:01:03.510 This is what is known as haptic feedback, 31 00:01:03.510 --> 00:01:05.520 and it provides a form of touch responsiveness 32 00:01:05.520 --> 00:01:07.500 from the display back to the end user, 33 00:01:07.500 --> 00:01:08.910 who's actually typing on it 34 00:01:08.910 --> 00:01:11.910 and using it to input information into the system. 35 00:01:11.910 --> 00:01:13.800 Now, when you're looking at the touchscreen itself, 36 00:01:13.800 --> 00:01:15.840 this digitizer has to be protected. 37 00:01:15.840 --> 00:01:19.140 And so, the digitizer has a piece of glass put on top of it. 38 00:01:19.140 --> 00:01:21.990 In most modern systems, this is going to be using some form 39 00:01:21.990 --> 00:01:24.810 of really strong glass like Gorilla Glass. 40 00:01:24.810 --> 00:01:26.970 This is a scratch-resistant shock-resistant 41 00:01:26.970 --> 00:01:29.610 type of temper glass that'll protect the digitizer 42 00:01:29.610 --> 00:01:31.110 and the underlying liquid crystals 43 00:01:31.110 --> 00:01:33.300 that are in that particular display. 44 00:01:33.300 --> 00:01:35.550 Next, we have the accelerometer. 45 00:01:35.550 --> 00:01:38.040 Now, the accelerometer is a combination device 46 00:01:38.040 --> 00:01:39.870 that uses hardware and software 47 00:01:39.870 --> 00:01:41.670 to measure the velocity, rotation, 48 00:01:41.670 --> 00:01:44.190 and shaking of that mobile device. 49 00:01:44.190 --> 00:01:46.770 Now, the accelerometer really focuses on movement 50 00:01:46.770 --> 00:01:50.700 caused by gravity or vibration, or by a quick acceleration. 51 00:01:50.700 --> 00:01:54.210 For example, if I take my smartphone, and I move it with me 52 00:01:54.210 --> 00:01:56.550 as I'm swinging my arm, it can detect the fact 53 00:01:56.550 --> 00:01:58.920 that I have that forward momentum happening, 54 00:01:58.920 --> 00:02:01.560 and it can detect how fast that's happening. 55 00:02:01.560 --> 00:02:04.020 Now, why would you want to use an accelerometer? 56 00:02:04.020 --> 00:02:06.150 Well, there's a lot of reasons we use accelerometers 57 00:02:06.150 --> 00:02:08.490 in our mobile devices, but the most common one 58 00:02:08.490 --> 00:02:10.380 is for our screen orientation. 59 00:02:10.380 --> 00:02:12.120 If you pick up your phone to take a picture, 60 00:02:12.120 --> 00:02:14.940 and you're holding it upright in a vertical format, 61 00:02:14.940 --> 00:02:16.950 you're going to only be able to see things that are tall, 62 00:02:16.950 --> 00:02:17.940 like a building. 63 00:02:17.940 --> 00:02:19.590 But if you turn it to the side, 64 00:02:19.590 --> 00:02:21.450 and now it's in a horizontal format, 65 00:02:21.450 --> 00:02:24.120 your screen also turns to the side too. 66 00:02:24.120 --> 00:02:25.440 Well, it's the accelerometer 67 00:02:25.440 --> 00:02:26.700 that's doing that for you. 68 00:02:26.700 --> 00:02:29.040 The accelerometer is able to detect the motion 69 00:02:29.040 --> 00:02:31.290 of going from that vertical orientation 70 00:02:31.290 --> 00:02:33.000 into the horizontal orientation, 71 00:02:33.000 --> 00:02:35.100 and it sends that signal to the operating system 72 00:02:35.100 --> 00:02:36.960 to change the display that's being output, 73 00:02:36.960 --> 00:02:38.640 to accommodate for that. 74 00:02:38.640 --> 00:02:41.040 In addition to this, you'll also find accelerometers 75 00:02:41.040 --> 00:02:43.260 inserted into a lot of laptops. 76 00:02:43.260 --> 00:02:45.240 The reason for this is that if your laptop 77 00:02:45.240 --> 00:02:47.610 has a traditional hard drive, and you drop it, 78 00:02:47.610 --> 00:02:50.070 that hard drive could be damaged really badly 79 00:02:50.070 --> 00:02:52.290 if it was in the middle of reading or writing data, 80 00:02:52.290 --> 00:02:54.660 because the actuator arm can scratch the surface 81 00:02:54.660 --> 00:02:56.250 of the hard drive's platters. 82 00:02:56.250 --> 00:02:58.320 But if your laptop has an accelerometer, 83 00:02:58.320 --> 00:03:00.300 and it detects that it's being dropped, 84 00:03:00.300 --> 00:03:03.090 it can send a signal to the hard drive to park the actuator, 85 00:03:03.090 --> 00:03:05.340 and make it so that the actuator stops reading and writing 86 00:03:05.340 --> 00:03:07.230 from the hard drive during the fall. 87 00:03:07.230 --> 00:03:09.360 And this can prevent data loss on that drive 88 00:03:09.360 --> 00:03:10.710 during the drop. 89 00:03:10.710 --> 00:03:12.720 Now, the accelerometer is pretty helpful, 90 00:03:12.720 --> 00:03:14.640 and can be used in games as well. 91 00:03:14.640 --> 00:03:16.950 For example, if I wanted to take my iPhone 92 00:03:16.950 --> 00:03:18.270 and play a driving game, 93 00:03:18.270 --> 00:03:20.280 I can turn the device left and right, 94 00:03:20.280 --> 00:03:21.960 and it will be able to detect that turn, 95 00:03:21.960 --> 00:03:24.090 and then turn the car in the game. 96 00:03:24.090 --> 00:03:26.160 This is another way you can use the accelerometer 97 00:03:26.160 --> 00:03:28.170 with different applications on your smartphone, 98 00:03:28.170 --> 00:03:30.150 to take that physical real world input, 99 00:03:30.150 --> 00:03:31.860 and then use that to control what's happening 100 00:03:31.860 --> 00:03:33.840 inside that application. 101 00:03:33.840 --> 00:03:35.790 Now, an accelerometer works really well 102 00:03:35.790 --> 00:03:38.100 when you're dealing with the X and Y axis, 103 00:03:38.100 --> 00:03:40.620 which is the horizontal and vertical axis, 104 00:03:40.620 --> 00:03:42.209 but it does not do a good job 105 00:03:42.209 --> 00:03:45.510 if you start moving things forward and backwards, 106 00:03:45.510 --> 00:03:46.740 which is known as depth. 107 00:03:46.740 --> 00:03:48.570 This is our Z axis. 108 00:03:48.570 --> 00:03:50.820 To be able to add Z, we need to add something 109 00:03:50.820 --> 00:03:52.770 known as the gyroscope. 110 00:03:52.770 --> 00:03:55.140 Now, a gyroscope is essentially an improved version 111 00:03:55.140 --> 00:03:57.060 of the basic accelerometer. 112 00:03:57.060 --> 00:03:59.790 When you use a gyroscope, you can detect pitch, 113 00:03:59.790 --> 00:04:02.760 roll, and yaw, and this allows you to control movements 114 00:04:02.760 --> 00:04:06.570 in three dimensions, using the X, Y, and Z axis. 115 00:04:06.570 --> 00:04:09.270 So, if I'm playing a car game, being able to move the phone 116 00:04:09.270 --> 00:04:11.490 to the left or the right, that is fine, 117 00:04:11.490 --> 00:04:13.680 and I can detect that using just the accelerometer, 118 00:04:13.680 --> 00:04:15.480 using the X and Y axis. 119 00:04:15.480 --> 00:04:17.460 But if I'm playing a flight simulator, 120 00:04:17.460 --> 00:04:19.590 I also need to be able to pull the phone closer to me, 121 00:04:19.590 --> 00:04:22.650 or away from me, to make my plane go up or down. 122 00:04:22.650 --> 00:04:25.050 And so, if you want a realistic flying game, 123 00:04:25.050 --> 00:04:26.850 you're going to need to measure the rate of rotation 124 00:04:26.850 --> 00:04:29.250 around the X, Y, and Z axis, 125 00:04:29.250 --> 00:04:31.860 and you can do that using a gyroscope. 126 00:04:31.860 --> 00:04:34.740 Similarly, if you've ever explored a 3D photo or video 127 00:04:34.740 --> 00:04:37.020 on your phone, you're using the gyroscope 128 00:04:37.020 --> 00:04:39.300 to move yourself around that space, 129 00:04:39.300 --> 00:04:41.130 and be able to see exactly what's going on 130 00:04:41.130 --> 00:04:42.900 in all 360 degrees, 131 00:04:42.900 --> 00:04:46.410 because you're moving across the X, Y, and Z axis. 132 00:04:46.410 --> 00:04:47.670 Now, in addition to using this 133 00:04:47.670 --> 00:04:50.310 for games, and looking at videos and photos, 134 00:04:50.310 --> 00:04:53.190 you can also use it to perform actions on your phone. 135 00:04:53.190 --> 00:04:54.840 In most modern smartphones, 136 00:04:54.840 --> 00:04:57.030 there is adaptive technology inside of them 137 00:04:57.030 --> 00:04:59.220 that pairs with software in the operating system 138 00:04:59.220 --> 00:05:01.560 to allow you to do things like gestures. 139 00:05:01.560 --> 00:05:03.960 For example, you could configure your smartphone 140 00:05:03.960 --> 00:05:05.850 that, every time you shake it three times, 141 00:05:05.850 --> 00:05:09.120 it's going to randomly shuffle your music and pick a new song. 142 00:05:09.120 --> 00:05:11.130 Or you might make it that if you shake the phone 143 00:05:11.130 --> 00:05:14.040 left to right, it's going to hang up or decline a phone call 144 00:05:14.040 --> 00:05:15.570 that's coming in for you. 145 00:05:15.570 --> 00:05:17.070 All these are things that are made possible 146 00:05:17.070 --> 00:05:20.490 by using that gyroscope inside of your smartphone. 147 00:05:20.490 --> 00:05:22.560 The final thing we use our gyroscope for 148 00:05:22.560 --> 00:05:24.390 is image stabilization. 149 00:05:24.390 --> 00:05:26.820 A lot of our camera apps inside of our smartphone 150 00:05:26.820 --> 00:05:29.280 actually pair themself with the gyroscope, 151 00:05:29.280 --> 00:05:31.200 and they use this as a way to detect 152 00:05:31.200 --> 00:05:33.060 what motion is happening with the camera, 153 00:05:33.060 --> 00:05:35.460 and to counteract that using digital filters, 154 00:05:35.460 --> 00:05:37.620 to be able to give us clear photos and videos 155 00:05:37.620 --> 00:05:40.110 with less vibrations and less shaking. 156 00:05:40.110 --> 00:05:42.330 These are all benefits of using a gyroscope 157 00:05:42.330 --> 00:05:44.040 inside of your smartphone. 158 00:05:44.040 --> 00:05:46.470 So, keep in mind, when it comes to mobile devices, 159 00:05:46.470 --> 00:05:48.690 there are three main components that you should be aware of, 160 00:05:48.690 --> 00:05:49.920 and their function. 161 00:05:49.920 --> 00:05:53.790 This is the digitizer, the accelerometer, and the gyroscope. 162 00:05:53.790 --> 00:05:55.260 When it comes to a digitizer, 163 00:05:55.260 --> 00:05:57.600 this is all about taking your tactile input, 164 00:05:57.600 --> 00:05:59.100 and converting it to digital signals 165 00:05:59.100 --> 00:06:01.470 that can be understood by the operating system. 166 00:06:01.470 --> 00:06:03.090 When it comes to the accelerometer, 167 00:06:03.090 --> 00:06:04.590 we are measuring the speed of change 168 00:06:04.590 --> 00:06:08.700 along the X and Y axis, which is horizontal and vertical. 169 00:06:08.700 --> 00:06:11.910 And if we use a gyroscope, we are adding the Z axis to this, 170 00:06:11.910 --> 00:06:14.640 So we can see things in 360 degrees, 171 00:06:14.640 --> 00:06:17.010 going across the horizontal or X axis, 172 00:06:17.010 --> 00:06:20.220 the Y axis or vertical access, and the Z axis 173 00:06:20.220 --> 00:06:21.603 or the depth axis.