WEBVTT 00:00.180 --> 00:05.860 Let's now solve the bonus problem still with this code example. 00:06.180 --> 00:10.860 We're going to keep the exact same functionality, OK, which is to print on the same monitor when the 00:10.860 --> 00:12.830 buttons pressed and when the button is released. 00:13.230 --> 00:20.790 But in this case, we want to avoid multiple detections of this of this when we just press release the 00:20.790 --> 00:26.460 button once the what we are going to do is simply when we see that the state has changed, we are going 00:26.460 --> 00:31.500 to ignore the following states of the button for a few milliseconds. 00:31.740 --> 00:38.520 And as you will see, the code will be actually very similar to what we did when we wanted to avoid 00:38.520 --> 00:43.020 using the delay for an entity or for any action you want to do in parallel. 00:43.080 --> 00:45.940 OK, not exactly the same, but very similar. 00:46.980 --> 00:56.430 So what I'm going to do first here, I'm going to create two global viral, unsigned, long last time 00:57.300 --> 01:01.540 button changed and initialized to me. 01:01.720 --> 01:05.810 So with this, we are going to keep the time and simply when we change. 01:06.180 --> 01:12.720 So when we monitor that the button state has changed, we are going to keep a record of that. 01:13.430 --> 01:22.070 So we know when was the last time the button changed so we can wait and see how long the bounce delay 01:22.090 --> 01:25.530 so we can wait for the DBMS delay before reading again. 01:26.100 --> 01:32.580 And I'm going to use fifty milliseconds, OK, and the default value, we are going to try with this 01:32.580 --> 01:33.030 first. 01:33.480 --> 01:41.340 So we have to violence here for the time we have our button state in which we still need to keep then 01:41.340 --> 01:42.150 in the setup. 01:42.150 --> 01:44.900 No need to change anything and not in the loop. 01:45.600 --> 01:52.350 What I'm going to do, I'm going to first and long time. 01:52.830 --> 01:54.300 I'm going to get the time. 01:56.060 --> 02:00.870 The current stank, so every time we go in the loop, I'm going to get the quarantine, OK? 02:01.440 --> 02:07.560 And this quarantine will, of course, increase every time I go in the look and I'm going to check if. 02:08.960 --> 02:14.390 Time now, minus the last time the burden changed. 02:15.200 --> 02:17.750 If this is greater than the deboned delay. 02:19.290 --> 02:22.350 Then we can enter the if. 02:23.360 --> 02:31.130 And then what we can do is we can read I'm going to put that in if we can read the brain state and then 02:31.130 --> 02:38.060 check if the button I'm going to please, Jake, if the button state is different from the previous 02:38.060 --> 02:38.450 one. 02:39.170 --> 02:40.940 OK, we're going to do an action. 02:41.180 --> 02:43.630 And two important things here. 02:44.190 --> 02:46.060 We are going to update you. 02:46.190 --> 02:48.260 The last time button changed. 02:48.860 --> 02:51.230 I'm going to write it and then explain why. 02:51.560 --> 02:52.280 So last. 02:53.510 --> 03:06.950 Time, but changed is equal to time, no, and then one state is equal to New York State and here do 03:06.980 --> 03:09.400 the action, whatever action we want to do. 03:09.800 --> 03:10.970 So what's happening here? 03:11.570 --> 03:18.710 The first the last time button change will be initialized to zero when we until we check the current 03:18.710 --> 03:19.190 time. 03:19.230 --> 03:22.790 OK, if the current time minus the last time to and change. 03:22.790 --> 03:29.780 So the duration between the time now and when we change the button, if this duration is greater than 03:29.780 --> 03:35.780 the duration we have set for the DBMS, delay we can enter is the look of now we are going to read the 03:35.780 --> 03:39.290 new button state and either state is still the same as before. 03:39.410 --> 03:44.280 So if it was low and no, it's too low, then we are not going to enter this if. 03:44.540 --> 03:51.590 OK, so we go out and the next time we enter the loop we can still go in the if, OK, because we have 03:51.590 --> 03:53.180 not updated the last time. 03:53.180 --> 03:56.210 But it changed, you know, like we did for the energy previously. 03:56.210 --> 04:02.690 We don't want to make sure that we execute this only every 50 milliseconds or every whatever time we 04:02.690 --> 04:10.550 can rig this as fast as we want is just when the button will change, when the new button state is different 04:10.550 --> 04:11.690 from the previous one. 04:12.110 --> 04:17.000 In that case, we are going to update this variable with the time. 04:17.000 --> 04:19.130 No, OK, and this is different from before. 04:19.130 --> 04:22.470 Before what we did is we simply added the delay here. 04:22.800 --> 04:26.570 Here what we do is we update the last time button change with time. 04:26.570 --> 04:26.930 No. 04:27.600 --> 04:32.080 OK, because this is the time when the button state has changed. 04:32.390 --> 04:36.680 So we just record the exact time when the button state has changed. 04:36.920 --> 04:44.240 And now when we go back in the loop time now minus last time button changed will not be greater and 04:44.240 --> 04:44.960 dbms zedi. 04:45.380 --> 04:53.180 So here we will only be able to go back in that if only if we have spent at least 50 milliseconds after 04:53.180 --> 04:55.320 we have ADT this valuable. 04:55.370 --> 05:02.300 So after the state of the button has changed, basically when we change the state of the button, we 05:02.300 --> 05:10.520 don't go here and we ignore this block for fifty milliseconds, which means that any bounce that will 05:10.520 --> 05:15.680 happen physically will still happen physically, but we are not going to read that bounce. 05:16.040 --> 05:21.350 OK, so now here we know that we can do the action and the action is simply the same as before. 05:24.210 --> 05:29.790 I'm going to copy this here and select and press double. 05:31.040 --> 05:32.270 And just remove that. 05:33.840 --> 05:35.790 All right, so now when we enter this. 05:37.240 --> 05:40.600 We can be pretty sure that this is not the bounce, OK? 05:40.620 --> 05:42.540 This is the real change of state. 05:43.140 --> 05:46.420 I'm going to upload the program. 05:48.680 --> 05:54.170 OK, and open the sale monitor, and now I'm going to press the button, I'm going to read it, but 05:54.240 --> 05:58.750 I'm OK and well, you can try as many times as you want. 05:59.440 --> 06:07.030 You will not get a price and release more than one time when you just press and release one thing, 06:07.730 --> 06:08.000 OK? 06:08.000 --> 06:10.690 And we have sold the bones, probably. 06:11.030 --> 06:13.490 Now let's modify these DBMS dillehay. 06:14.730 --> 06:21.440 Let's say, but zero, if I put zero, it means that just this structures is useless, OK? 06:21.450 --> 06:27.780 Because every time we are going to enter this, if we are not going to wait any time after the state 06:27.780 --> 06:34.680 has changed, OK, let's try with zero and let's see that we can have when talk. 06:35.590 --> 06:36.690 I'm going to press. 06:46.210 --> 06:49.310 OK, and you can see here we have the dance issue. 06:49.330 --> 06:51.440 OK, we don't press the button, really. 06:51.460 --> 06:57.130 You can see about the same time we have one moment in person, but unreleased. 06:58.950 --> 07:06.200 Now, I go back to my program and put correct values so you can but what I'm going to put 30 milliseconds 07:06.540 --> 07:08.060 that will work from my second. 07:08.700 --> 07:11.620 The thing is how to actually know which value you can sit here. 07:11.640 --> 07:15.690 So 50 or 30 milliseconds is already quite a good value. 07:15.720 --> 07:16.500 It should work. 07:17.050 --> 07:18.710 You can try different values. 07:19.050 --> 07:25.420 So the tradeoff here is simply if you put a value to low, well, you might still have bonuses. 07:25.440 --> 07:27.400 So let's say you put only three milliseconds. 07:27.750 --> 07:29.620 You might still see Bonsey. 07:29.640 --> 07:36.330 So you want to put a value high enough, but not too high, because if it's too high, well, this means 07:36.790 --> 07:42.070 the delay means that you're going to ignore the state for the button for a few milliseconds, OK? 07:42.300 --> 07:45.250 So if I just say, OK, I'm going to get 1000. 07:46.050 --> 07:52.740 The thing is that if I press release the button in less than one second, I'm going to meet also the 07:52.740 --> 07:55.590 real change of state when I release the button. 07:55.770 --> 08:00.030 So you want the value to be high enough so it doesn't get any bounce in it. 08:00.300 --> 08:03.010 But you also want it to be not too high. 08:03.300 --> 08:05.650 So you don't miss real change of state. 08:06.180 --> 08:06.560 All right. 08:06.570 --> 08:09.480 I know you can see Destructo here we went. 08:09.480 --> 08:14.680 We could have done in the program here after we read the button and we checked that. 08:14.790 --> 08:20.070 But instead from here, we could just dump a delay, for example, delete. 08:21.230 --> 08:25.650 Fifty milliseconds and just not use all of the structure. 08:25.880 --> 08:30.230 This would have been the same for this program, but then, as you know, with the delay, the problem 08:30.230 --> 08:33.320 is that we are going to stop the execution here. 08:33.590 --> 08:40.130 So if we want to do anything else other than this, well, that would be a problem with Destructo. 08:40.310 --> 08:42.000 We can go very, very fast. 08:42.020 --> 08:43.630 OK, you can see it. 08:43.640 --> 08:45.500 We read the time and then we have if. 08:45.800 --> 08:52.080 OK, so either we enter the if or not and then the actions will be very fast to execute. 08:52.560 --> 08:58.670 So if we have another action here, then this will not be a problem for the action to. 09:00.050 --> 09:06.380 All right, and the thing I want to emphasize is that you are going to be the last time the burden changed 09:06.680 --> 09:13.520 after the State of Union has changed, not just when you read it, but after you read it and that you 09:14.150 --> 09:16.570 see that the Golden State has changed. 09:16.760 --> 09:21.050 Only then you will have the desirable and updated with the time now.