WEBVTT 00:00.210 --> 00:06.240 Let's not see how to use interrupts in your original program, so what I'm going to do here, I'm going 00:06.240 --> 00:13.080 to make a very simple application where when we press the button, we are going to toggle an entity 00:13.410 --> 00:15.790 that might sound familiar to you already. 00:16.050 --> 00:16.420 So what? 00:16.440 --> 00:20.250 I'm going to initialize the hardware stuff. 00:20.260 --> 00:21.380 OK, so that is done. 00:21.390 --> 00:22.880 So define thing. 00:23.160 --> 00:26.160 I'm going to use the 12 define. 00:27.290 --> 00:34.760 Button in which is being number two, and you can see that I have put the button on the pin number two 00:34.760 --> 00:35.340 and purple. 00:35.390 --> 00:41.300 OK, at the beginning of this course, because if you remember here, I'm using an outer window and 00:41.300 --> 00:46.350 only digital pins you can use for interrupts our pin number two and pin number three. 00:46.520 --> 00:52.790 So if you have put your pushbutton in a different pin, well, make sure that you look at the table 00:52.820 --> 00:54.740 I have provided in the previous lesson. 00:54.740 --> 01:01.760 And that corresponding to your order, would you connect the push-Button to a pin that can support interrupts? 01:03.100 --> 01:04.460 OK, so in the setup. 01:05.590 --> 01:07.570 In mode and the. 01:09.530 --> 01:12.410 We upwards and then being. 01:15.030 --> 01:16.950 But being weak. 01:17.940 --> 01:24.140 So if you're going to use an interrupt on a digital Benwell, nothing changes for the initialization, 01:24.150 --> 01:24.370 OK? 01:24.390 --> 01:27.130 You just set the scene as inputs. 01:27.180 --> 01:28.720 OK, that is the same. 01:29.400 --> 01:31.540 And now let's create an interactive. 01:31.920 --> 01:37.110 So to create an interrupt in your Uninor program, you have to do two things. 01:37.470 --> 01:39.430 First, create a function. 01:39.840 --> 01:40.950 I'm going to call it. 01:42.430 --> 01:46.060 Button released direct. 01:48.630 --> 01:51.450 And then use the attach. 01:52.900 --> 01:53.560 Interrupts. 01:54.910 --> 01:55.700 Function, OK? 01:55.720 --> 02:01.990 You can use it in your setup, for example, or anywhere in your code, that usually that's what we're 02:01.990 --> 02:04.940 going to do in setup after we initialize the pin. 02:05.590 --> 02:07.850 And here we are going to choose the mode fully. 02:07.910 --> 02:14.590 OK, so following if your Roomba is when the signal goes from high to low, in other words, without 02:14.590 --> 02:17.780 secret falling is when we release the button. 02:17.800 --> 02:23.260 OK, because when we press the button, the signal will go to high and when we release the button, 02:23.260 --> 02:24.790 the signal will go to low. 02:25.000 --> 02:28.360 So we can use fulling and because we use fulling. 02:28.360 --> 02:33.110 I have named the function here button released into it. 02:33.280 --> 02:40.780 OK, if you were using, for example, rising, you could name the function button pressed into it. 02:41.020 --> 02:43.420 OK, make sure you give meaningful names. 02:43.450 --> 02:49.240 So in this attachment or a function, I need to provide three argument. 02:49.540 --> 02:50.620 First the thing. 02:50.650 --> 02:55.010 So the button pin, then what I'm getting here, the callback function. 02:55.020 --> 03:00.180 So the function to call when to interrupt is triggered and there is the mode. 03:01.030 --> 03:03.830 So let's start to set up the PIN number. 03:03.850 --> 03:06.400 We are not just going to button up like this. 03:06.400 --> 03:11.650 We're going to need to use another function which is called digital pin to. 03:12.680 --> 03:13.400 Interact. 03:13.860 --> 03:15.530 OK, you can see it turn. 03:17.070 --> 03:17.390 OK. 03:18.090 --> 03:25.970 OK, button that we use digital ping to interact with button ping that we put as the first argument 03:25.970 --> 03:27.970 in the attach interact. 03:29.220 --> 03:29.630 OK. 03:29.690 --> 03:32.000 And then the second argument will be. 03:33.980 --> 03:41.360 Dysfunction, as you can see, the line is quite long, so what I'm going to do here and I encourage 03:41.360 --> 03:47.510 you to do when you have a function with many parameters, is go back to a new line supercenter and then 03:47.510 --> 03:51.980 I'm going to align in the beginning of the disease. 03:52.370 --> 03:56.420 So you press enter after the coma, OK? 03:57.610 --> 04:02.650 OK, I have a new argument, so I'm going to press enter here after the command, not everything is 04:02.650 --> 04:03.590 aligned, so that's good. 04:04.030 --> 04:06.940 So I have digital ping to interact with the button ping. 04:08.180 --> 04:13.100 The name of the function without parents is without anything, just the name of the function. 04:13.130 --> 04:14.930 OK, but don't really interrupt. 04:15.140 --> 04:16.040 And then the mode. 04:16.250 --> 04:17.300 So the mode is. 04:18.600 --> 04:22.140 Falling and as you can see, falling turns blue. 04:22.440 --> 04:29.730 OK, this is a key word, if you were using rising, for example, would turn blue also and change also. 04:29.940 --> 04:30.310 OK. 04:32.170 --> 04:35.970 Fully, and then I close the parentheses and semicolon. 04:36.880 --> 04:45.220 OK, so what this will do is to attach and interact on this pin, OK, for the following mode and calling 04:45.220 --> 04:46.570 the button interrupts. 04:46.570 --> 04:55.090 So now from this point after the line 12, whenever the signal on the PIN number two goes from high 04:55.090 --> 04:57.920 to low, this function will be called. 04:58.240 --> 05:04.690 So wherever we are in the program, the program will stop, the execution will stop, and this function 05:04.690 --> 05:05.350 will be called. 05:05.560 --> 05:11.510 After this function has finished, the program will resume wherever it is. 05:11.860 --> 05:18.800 OK, and one important thing here for the interim function, you should have avoid that type, OK? 05:18.830 --> 05:22.970 You should not return anything and you should not have any parameter. 05:23.190 --> 05:28.840 OK, that's the two conditions or interim function void and no parameter. 05:29.560 --> 05:30.310 What we want to do. 05:30.340 --> 05:34.160 We want to toggle the entity when we release the button. 05:34.660 --> 05:38.560 What I'm going to do, I'm going to create another function. 05:39.040 --> 05:40.530 Toggle edit OK. 05:42.350 --> 05:50.990 And in this function, so I'm going to create vitality, the rate is low, initialized to low. 05:51.200 --> 05:54.110 So this we already have done it a few times before. 05:54.140 --> 05:57.790 OK, I'm going to go quite fast if you. 05:59.070 --> 06:01.390 They is low. 06:01.590 --> 06:04.320 I would just invest. 06:05.230 --> 06:09.760 Every state becomes I, it ends. 06:13.670 --> 06:20.150 State becomes law, and after we have changed the state, we do digital. 06:22.850 --> 06:25.220 And the thing with the. 06:28.860 --> 06:34.890 OK, so we keep the state of the 80s, so whenever we enter the target area, we check what was the 06:34.890 --> 06:41.040 current state would change it to the other one because the only two states and then we use digital rights 06:41.040 --> 06:43.730 to apply the new state to the atypia. 06:44.040 --> 06:46.850 So then by using this, it's nice and clean. 06:46.860 --> 06:52.640 We have a function that does just what we wanted to do so we can just go ahead. 06:52.710 --> 06:59.670 We don't need to repeat that code anywhere else in the program and know what we could do is to call 06:59.670 --> 07:05.610 the toggle and inside the button, really interrupt, OK, because that's what we want to do. 07:05.940 --> 07:09.000 But that's not what we are going to do, actually. 07:09.540 --> 07:10.260 Why is that? 07:10.620 --> 07:17.100 Because the interim function will block your program, which stopped your program, and it's also going 07:17.100 --> 07:20.180 to disable every other interrupt. 07:20.330 --> 07:25.140 OK, so you have to know that in order, you know, you can create interrupts like this. 07:25.290 --> 07:30.900 But there are also other interrupts that run in the background that you may not be aware of. 07:31.050 --> 07:36.630 But the thing is that when you create and when you are in an interim function, every other interrupt 07:36.630 --> 07:41.960 is disabled and your main program is completely stopped looking. 07:41.960 --> 07:48.210 Hear what's wrong with that is that we use digital right to write is a function to do an action and 07:48.210 --> 07:51.060 this will take a few microseconds. 07:51.370 --> 07:54.560 OK, and this is more than just changing the state. 07:54.570 --> 07:56.280 OK, changing variable. 07:56.580 --> 08:02.970 So a best practice for an interim function is just to change some variables. 08:02.970 --> 08:07.530 And then after you have changed some buyable, you will handle the action in the loop. 08:07.590 --> 08:09.510 OK, let's see how to do that. 08:09.960 --> 08:17.650 I'm not going to do add in the interrupt that would work for this example, but this is not a good practice. 08:18.210 --> 08:21.510 Instead, what I'm going to do is create a boolean. 08:22.930 --> 08:27.050 So when I create a boolean variable, I can also call it a flag. 08:27.290 --> 08:30.640 OK, like this button release. 08:32.500 --> 08:33.610 Which is false. 08:34.510 --> 08:39.360 And when we are in the interim and is going to do but then released. 08:40.490 --> 08:48.710 Is true, though, I said the fly, which means that I put the value to true inside this boolean and 08:48.710 --> 08:52.000 note that this is important when you use a valuable. 08:52.310 --> 08:59.270 So when you use a global valuable insight, an interim function, what you have to do when you're declared 08:59.270 --> 09:04.640 valuable, you have to add another keyword in front of the data type. 09:04.880 --> 09:06.170 And this keyword is. 09:10.090 --> 09:17.170 OK, so whenever you use a valuable insight, an interrupts, make the viable, volatile and by using 09:17.170 --> 09:23.440 volatile, you are just telling the world, you know, that you are going to use this valuable also 09:23.450 --> 09:27.010 interrupt so you may handle it better. 09:27.510 --> 09:35.410 OK, and so now after we have set this flag so the button rose to true do what we can do is in the look 09:35.410 --> 09:35.890 function. 09:36.950 --> 09:38.660 We are just going to check if. 09:39.530 --> 09:40.910 But then released. 09:41.820 --> 09:45.160 So when you take for a billion, you don't need to do this, OK? 09:45.450 --> 09:51.840 You don't need to check if the blame is true because the billion is already a bullion, so it's already 09:51.840 --> 09:52.540 bullion value. 09:52.560 --> 09:54.170 So this is just true. 09:54.190 --> 09:55.110 All this is false. 09:55.150 --> 10:02.250 OK, so if the button is released, then what we are going to do is we are going to do button release. 10:03.610 --> 10:07.150 Is false and Eric. 10:09.570 --> 10:17.250 So in the look on the on the action we do is to check for this flag it for this billion, if this balloon 10:17.250 --> 10:24.660 is true, we enter the if we unset the flag, so we set the boolean value to false or we don't enter 10:24.660 --> 10:25.440 it the next time. 10:25.560 --> 10:26.010 All right. 10:26.400 --> 10:28.000 And then we took the editing. 10:28.260 --> 10:31.730 So as you can see, your problem in the loop is very simple. 10:31.800 --> 10:33.150 Can you just check the flag? 10:33.420 --> 10:40.620 And then because you have attached and interact with the button and with this function whenever you 10:40.620 --> 10:47.460 release the button, OK, this will trigger the following mode, which will call this function, which 10:47.460 --> 10:54.090 will set this boolean to true OK, which means that the next time you read it in the loop, it is true 10:54.090 --> 10:55.620 and you can execute the action. 10:55.800 --> 11:01.830 And by doing this, you are sure that you don't miss the release of the button. 11:02.220 --> 11:02.630 All right. 11:02.700 --> 11:05.010 Now let's upload the program. 11:05.020 --> 11:06.150 So let's name it. 11:07.200 --> 11:07.880 Interrupts. 11:10.720 --> 11:19.330 OK, so you can see here the read, any on 12 is pulled off, I'm going to press on the button. 11:19.480 --> 11:26.320 You can see nothing happens and I Rollie's the button, the energy is put on, OK, when they release 11:26.320 --> 11:31.180 the button and then I press a release and then is put off. 11:31.180 --> 11:36.870 So the energy was just told, I'm going to go a little bit faster, OK. 11:38.050 --> 11:42.170 And as you can see, I just press another time and the energy is still on. 11:42.640 --> 11:43.300 Why is that? 11:43.570 --> 11:46.830 Well, we are coming back to the bones problem once again. 11:47.470 --> 11:54.130 So using interact with a push button in that specific situation means that you will know exactly when 11:54.130 --> 12:01.990 the state of the signal changes, but you still have the balance problem and the problem is simply a 12:01.990 --> 12:02.950 physical problem. 12:03.250 --> 12:07.730 So if we had the problem before with interrupts, we don't solve this problem. 12:08.290 --> 12:13.530 So in the next listen, we are going to see how to demand the button in the interrupt.