WEBVTT 00:00.180 --> 00:06.270 This is the solution of the previous activity when you need to create an automatic light system, so 00:06.270 --> 00:12.390 with two leads, one that you just going to pull up on under a certain threshold and the other one that 00:12.390 --> 00:16.710 will be put on with the right, so you will modify the brightness. 00:17.100 --> 00:20.820 So the less light, the higher the brightness. 00:21.120 --> 00:24.540 So first of all, I'm going to define that threshold, OK? 00:24.540 --> 00:33.330 For the engineering team to do that, I'm going to open the previous project we have created with the 00:33.330 --> 00:35.160 photoresistor here. 00:37.620 --> 00:41.100 So that is the code that we have just used before. 00:41.110 --> 00:45.370 I'm just going to make sure that is plugged and to upload it. 00:47.170 --> 00:53.690 And then using the science monitor or just let's use the sale plotter here, I'm just going to see so 00:53.710 --> 00:58.120 this is the value currently that I have with the luminosity I have in my room. 00:58.290 --> 01:01.750 OK, and if I put my hand, you can see it's going down. 01:02.260 --> 01:06.840 Basically, I can see that you have 300 or 400. 01:07.150 --> 01:12.750 So let's see, I can set a threshold at three hundred and let's say 30. 01:13.000 --> 01:21.400 So I'm sure that if the luminosity is like it is right now, then I consider this as daylight. 01:21.400 --> 01:28.330 And if it is lower, so if I put my hand or it's getting darker, then the energy will be put on. 01:28.810 --> 01:37.870 So let's go back to an activity code and I'm going to create here defined let's see, luminosity. 01:41.110 --> 01:41.620 Night. 01:43.010 --> 01:49.670 Threshold, which will be three hundred and thirty, so that's the first value and of course, you can 01:49.700 --> 01:54.320 add to it depending on your hardware set up and maybe I will modify it. 01:54.470 --> 01:58.190 And when I do the experiment, that's already already by value. 01:58.190 --> 02:00.940 And then, of course, you have to tinker that way. 02:01.550 --> 02:03.110 So, no, I don't have my threshold. 02:03.110 --> 02:08.780 Let's just use some other define for or to register. 02:10.780 --> 02:19.020 Being, which is a zero, let's just initialize all the pain, so any one that's the one thing is already 02:19.030 --> 02:26.120 the pain on 12 and define energy to being, which has been number 10. 02:27.190 --> 02:34.240 So in this setup, I don't need to initialize the photoresistor PIN because this is an analogy in between. 02:34.510 --> 02:37.920 I need to use spin mode for the LCD. 02:39.750 --> 02:49.600 One thing as output and also pin code for the ability to spin as output also. 02:50.040 --> 02:57.270 So whether I use digital right or analog right on the end it is I need to initialize them as output 02:58.350 --> 03:00.400 is done in the loop. 03:03.140 --> 03:09.140 So I'm going to read the view from the photoresistor ain't within it, OK, because the value we will 03:09.140 --> 03:12.150 read will be from zero to one thousand twenty three. 03:12.860 --> 03:22.750 So let's say Luminosity is equal to another read from the photoresistor Bill. 03:23.910 --> 03:31.860 So I get the value and now I can check for the threshold if and know that here, so I'm not going to 03:31.860 --> 03:38.010 add any delay and I'm not also going to use the time functionality because, well, here we can arrive 03:38.010 --> 03:38.600 at full speed. 03:38.610 --> 03:39.810 OK, that's not a problem. 03:39.870 --> 03:42.870 We can use the analogy whenever we enter the void loop. 03:42.870 --> 03:44.330 That's not going to pose any problem. 03:44.520 --> 03:50.370 However, for example, if you want to breed, let's say you want to also print the analog read, then 03:50.370 --> 03:52.310 maybe for printing that value. 03:52.320 --> 03:54.610 That would be great to use the time functionality. 03:54.630 --> 03:57.830 OK, for example, to print every one hundred milliseconds. 03:58.110 --> 04:01.430 But here we just take the value and then we just put on some LCD. 04:01.440 --> 04:02.670 So let's go full speed. 04:03.120 --> 04:05.430 So if the luminosity. 04:07.230 --> 04:10.260 Is lower than the threshold. 04:11.710 --> 04:16.450 So here I can use strictly lower or lower or equal, that's not really important. 04:16.480 --> 04:19.580 We are not that that's super precise with this. 04:20.090 --> 04:21.140 Not very important. 04:21.370 --> 04:24.370 So if it's lower than the threshold, I'm going to do digital. 04:24.910 --> 04:25.540 Right. 04:25.990 --> 04:34.300 Any one being high and else I'm going to do digital. 04:34.900 --> 04:35.440 Right. 04:35.740 --> 04:36.300 Any. 04:38.280 --> 04:46.140 One thing we've know, so if it's getting too dark, we were on the Petitti, it is getting lighter 04:46.140 --> 04:47.770 with power of the editing. 04:48.330 --> 04:48.560 Right. 04:48.660 --> 04:54.200 And now what we're going to do is to use unallowed right on the edit to people. 04:54.570 --> 04:57.860 But before that, we need to compute the value for the peak. 04:57.890 --> 05:04.060 So let's say it brightness is equal to. 05:04.530 --> 05:09.450 So we're going to use the luminosity we need to divide it by four. 05:09.480 --> 05:10.430 So let me know. 05:10.470 --> 05:12.440 A city divided by four. 05:12.960 --> 05:18.270 But actually, if we do that, the more luminosity, the greater the brightness. 05:18.300 --> 05:20.970 So what do we need to do is to reverse it and to reverse it. 05:21.000 --> 05:21.990 It's really simple. 05:21.990 --> 05:26.520 You do two hundred fifty five minus luminosity divided by four. 05:27.090 --> 05:32.780 And he had no need for parentheses because this has a higher priority of the subtraction. 05:33.270 --> 05:38.140 So 255 minus the luminosity divided by four. 05:38.640 --> 05:44.820 So if we have a high luminosity we will have low brightness and if we have a low luminosity, we will 05:44.820 --> 05:46.550 have a high brightness. 05:46.980 --> 05:50.040 And now let's do analogue right. 05:51.090 --> 05:55.820 To begin with brightness and that's it. 05:55.830 --> 05:57.670 So that's not a really long program. 05:58.050 --> 06:05.730 So now what I'm going to do, I'm going to upload that code to verify and upload activity 19. 06:08.610 --> 06:14.610 So he as you can see, we have the added to the green and PIN number 10, which is both on but with 06:14.610 --> 06:22.250 not the maximum brightness and the energy, the red pin, the 12 is pulled off. 06:22.560 --> 06:28.500 I'm going to put my hand and you can see I just put my hand here on top of the sensor and the energy 06:28.500 --> 06:29.750 will be both on. 06:29.940 --> 06:33.140 I remove my hands and it is put up. 06:33.290 --> 06:40.130 OK, this is just because I have a threshold that just corresponds to this luminosity. 06:40.200 --> 06:41.620 So it's very sensitive. 06:41.650 --> 06:49.530 No, you can see I just put my hand a little bit close to the sensor and automatically the energy will 06:49.530 --> 06:50.590 be put on. 06:51.570 --> 06:57.090 So when you do that, if you see that, for example, the energy is on too quickly, what you can do 06:57.090 --> 06:59.640 is simply you can reduce the threshold. 06:59.880 --> 07:04.860 Or if you see that it's hard to put on the energy, what you can do is increase the threshold. 07:05.290 --> 07:11.100 I'm going to add more light here and OK. 07:11.370 --> 07:17.520 And you can see well, I don't know if you can see clearly, but the green energy here, the brightness 07:17.550 --> 07:18.610 is lower. 07:18.930 --> 07:23.540 OK, if I turn off the light now, the brightness is higher. 07:24.360 --> 07:24.720 All right. 07:25.110 --> 07:27.600 As you can see, this is easy to do. 07:27.600 --> 07:33.510 And now you have a automatic light system that you can use for many different applications.