WEBVTT 00:00.110 --> 00:04.640 And let's not write the Arduino code to control the servo motor. 00:04.820 --> 00:14.030 So first of all, I am going to, of course, add a define servo pin, which is number 12. 00:14.060 --> 00:19.700 Then to initialize the servo I will need to include the servo library. 00:19.700 --> 00:21.260 So servo dot h. 00:21.320 --> 00:21.460 Okay. 00:21.470 --> 00:26.600 So we need it to include a library for the LCD screen as well for the servo. 00:26.690 --> 00:30.380 And then we are going to create a servo here in the global scope. 00:30.380 --> 00:37.430 So Servo, we use the name of the library and then let's name it Servo with as lowercase. 00:37.460 --> 00:37.910 Okay. 00:38.740 --> 00:40.600 So we just created like this. 00:40.630 --> 00:44.320 No parentheses, nothing in the void setup. 00:44.830 --> 00:49.390 I'm going to do servo dot attach. 00:49.390 --> 00:54.190 So we're going to basically attach a pin to control the servo motor. 00:54.190 --> 00:56.280 And of course, that's the servo pin. 00:56.290 --> 00:58.680 And now the servo is initialized. 00:58.690 --> 01:03.640 So if I want to give a command to the servo, I can do servo dot, right? 01:03.640 --> 01:04.910 And what can I give? 01:04.930 --> 01:06.190 I can give a number. 01:06.190 --> 01:10.330 So an integer number between 0 and 180. 01:10.630 --> 01:11.560 So what is that? 01:11.560 --> 01:16.420 Basically, a servo motor is not unlimited in what it can do. 01:16.450 --> 01:19.690 It can go from 0 to 180 degrees. 01:19.690 --> 01:22.390 So basically it can make half a rotation. 01:22.390 --> 01:24.790 You can't do more than that with a servo motor. 01:24.820 --> 01:25.190 Okay. 01:25.270 --> 01:31.150 So for example, if you want to control a wheel with your Arduino, well, that's not the kind of motor 01:31.150 --> 01:31.690 you want. 01:31.690 --> 01:35.350 You want a motor that can make more than one turn. 01:35.530 --> 01:35.950 Okay. 01:35.950 --> 01:44.090 So here, basically zero is going to be one extreme position and 180 is going to be the other extreme 01:44.090 --> 01:44.690 position. 01:44.690 --> 01:46.460 Let's put 50. 01:46.580 --> 01:46.960 Okay. 01:46.970 --> 01:50.750 So we're going to put the servo motor at 50. 01:50.930 --> 01:52.280 Well, actually, let's go to the middle. 01:52.280 --> 01:53.480 Let's go to 90. 01:53.510 --> 01:57.890 So that's going to be that should be the middle position of the servo motor. 01:57.890 --> 02:01.250 And let's upload that code to the Arduino. 02:01.250 --> 02:06.590 So connected upload and let's see what the servo is doing. 02:08.250 --> 02:09.600 Compiling and uploading. 02:10.320 --> 02:10.770 Okay. 02:10.770 --> 02:12.780 And you can see here the servo has moved. 02:12.810 --> 02:14.850 This is the middle position. 02:14.850 --> 02:19.020 So maybe if I want the middle position here, I can change. 02:19.050 --> 02:22.680 Maybe that plastic part to be around. 02:23.340 --> 02:25.710 Yeah, something like around the middle position. 02:25.710 --> 02:26.250 Okay. 02:26.310 --> 02:33.270 So it's going to be like this on the extreme position and is going to be like that on the lowest position 02:33.540 --> 02:37.140 and maybe your servo can make a little bit of noise. 02:37.170 --> 02:45.840 It's just that well, here the plastic gear is not a great quality and the servo might force a bit, 02:45.840 --> 02:47.850 but that's not really a problem here. 02:47.850 --> 02:51.390 Again, if you want to have a better quality, you can buy another servo. 02:51.420 --> 02:54.270 But for now, that's all we need. 02:54.270 --> 02:58.830 If you have that from your starter kit and then, well, I want to show you something more. 02:58.830 --> 03:04.770 Just because we're going to use that in the following is how to make the servo sweep. 03:04.770 --> 03:06.420 So basically the sweep example. 03:06.420 --> 03:12.880 So we're going to go from 0 to 180 and from 180 to 0 and that indefinitely. 03:12.880 --> 03:16.130 So you can see the servo move from one side to the other one. 03:16.150 --> 03:17.680 So I'm going to remove that. 03:17.680 --> 03:20.620 And in the void loop, I'm going to add a for loop. 03:20.620 --> 03:29.770 So for int, I is equal to zero, I lower than 180 and I plus plus. 03:29.770 --> 03:40.270 So basically we go from 0 to 180 and we do several dot write I and we add a delay of let's say ten milliseconds. 03:40.450 --> 03:45.940 So every ten milliseconds we increment the position from 0 to 180. 03:45.940 --> 03:50.020 And once we reach 180 degrees, we do for. 03:50.990 --> 03:54.230 INT i is equal to 180. 03:55.040 --> 04:00.560 I is greater than let's greater or equal than zero. 04:00.980 --> 04:03.400 I minus minus. 04:03.410 --> 04:07.700 So with this for loop we go from 180 to 0. 04:07.730 --> 04:08.000 Okay. 04:08.000 --> 04:14.430 Because we decrease, we decrement the counter every time servo here. 04:14.450 --> 04:22.160 It's better if it's correctly spelled right I and delay ten. 04:22.160 --> 04:28.550 So this is going to make the servo go from 0 to 180 degrees every ten milliseconds. 04:28.550 --> 04:32.840 This is going to make the servo go from 180 to 0. 04:32.840 --> 04:38.690 And then we come back here and we start at zero again and let's see what it does. 04:38.690 --> 04:43.910 So let's upload and let's check the servo motor, okay? 04:43.910 --> 04:49.820 And you can see the servo is going from the minimum to the maximum position and coming back. 04:49.820 --> 04:55.920 So now, well, if you want to stop this, what you can do is you can upload another program that doesn't 04:55.920 --> 05:00.750 use the servo or what I usually do is quite safe to do. 05:00.750 --> 05:05.040 I just disconnect the wire on the PIN number 12 here. 05:05.040 --> 05:07.020 You can see the command wire. 05:07.050 --> 05:08.130 Okay, that's it. 05:08.160 --> 05:09.570 I don't disconnect the ground. 05:09.570 --> 05:10.730 I don't disconnect the power supply. 05:10.730 --> 05:16.080 I just disconnect the command and I make sure that this doesn't touch anything else. 05:16.080 --> 05:16.620 Okay. 05:16.860 --> 05:22.050 So I can continue with my experiment, and I don't need to upload an empty code. 05:22.530 --> 05:23.190 All right? 05:23.190 --> 05:29.340 And, well, that's the end of this section where we built the Arduino circuit for the following of 05:29.340 --> 05:29.940 the course. 05:29.940 --> 05:36.330 Let's now get some practice with those components which we are going to control from the Raspberry Pi.