WEBVTT 00:00.020 --> 00:05.690 This is step number ten and also the final step of this intercom project. 00:05.690 --> 00:11.810 So at this point, we have correctly written the complete Arduino program and the complete Python program. 00:11.810 --> 00:13.720 So what else do we need to do actually? 00:13.730 --> 00:18.920 Well, if you have noticed, whenever you want to start the Python project on the Raspberry Pi, well, 00:18.920 --> 00:20.450 you need to boot the Raspberry Pi. 00:20.480 --> 00:27.380 You need to log in in the desktop or we just command line with SSH and then you need to start the script. 00:27.380 --> 00:30.920 So you need to start the python script manually every time. 00:30.920 --> 00:35.150 Now a Raspberry Pi is nice because it's very small and you can put it anywhere. 00:35.150 --> 00:39.200 So what if we make the program just start on boot? 00:39.200 --> 00:43.640 So when you boot the Raspberry Pi, the program is just also starting. 00:43.640 --> 00:45.140 That would be nice, right? 00:45.140 --> 00:46.640 And that's what we are going to do. 00:46.640 --> 00:52.310 So then the next time you put your Raspberry Pi, you don't need to log in to the desktop. 00:52.340 --> 00:54.380 The application is just going to work. 00:54.560 --> 00:57.110 And to do that we are going to use systemd. 00:57.110 --> 00:59.720 So this is not the course about systemd, right? 00:59.720 --> 01:04.710 This is just a small improvement for the project as a kind of a bonus step. 01:04.710 --> 01:10.110 So I'm just going to show you what you need to do step by step, but very simplified explanation. 01:10.110 --> 01:12.330 I'm not going to dive into the details. 01:12.450 --> 01:15.750 And so first of all, we are going to go. 01:16.580 --> 01:25.040 You in Python program where we have our intercom step nine, I'm going to put it as executable with 01:25.040 --> 01:32.870 c h mode plus X intercom, step nine, and you can see it should turn green. 01:33.050 --> 01:33.320 Okay. 01:33.320 --> 01:35.870 That's something that's going to be important for this step. 01:35.870 --> 01:41.870 And then I can do, for example, intercom step nine can launch it like this. 01:41.990 --> 01:43.550 So this is working. 01:43.550 --> 01:50.140 I have not connected the Arduino board actually here and I can also launch it with Python three intercom 01:50.150 --> 01:51.590 step nine. 01:51.980 --> 01:52.370 Okay. 01:52.370 --> 01:54.680 That is the same thing. 01:54.680 --> 02:07.520 So now that your script is executable, let's go to slash lib slash system D slash system press enter 02:08.240 --> 02:08.960 to clear. 02:09.350 --> 02:10.730 And what do we have? 02:10.730 --> 02:12.350 Well, we have a lot of things. 02:12.890 --> 02:19.310 And basically those you can see many of those files are something dot service. 02:19.700 --> 02:27.020 So we are going to create another file, another service and then make the service start on boot. 02:27.290 --> 02:29.300 So let's just follow the steps here. 02:29.300 --> 02:36.140 So you do sudo nano to create file, you need sudo because we are not in the home directory. 02:36.430 --> 02:37.100 Right. 02:37.100 --> 02:44.990 And then let's name it intercom dash project dot service. 02:45.260 --> 02:45.710 Okay. 02:45.710 --> 02:47.150 And what are we going to write? 02:47.150 --> 02:55.160 So this is a specific structure you need to follow first with brackets Unit Description. 02:56.330 --> 02:59.150 So the description is anything you want. 02:59.180 --> 03:05.630 For example, intercom system, it doesn't really matter here. 03:06.140 --> 03:07.910 And then you have after. 03:07.910 --> 03:09.890 So write exactly like this. 03:09.890 --> 03:14.900 You're going to put multi slash user dot target. 03:15.680 --> 03:20.460 So well this is just to say that the program, the service is going to run after this. 03:20.460 --> 03:23.100 So you have many different steps in the boot. 03:23.130 --> 03:23.790 Okay. 03:23.790 --> 03:29.550 And if you want to run a Python program, you're just going to get you're just going to use multi user 03:29.580 --> 03:30.720 dot target. 03:30.720 --> 03:37.740 So that is going to wait a bit until the environment is ready to start the script after unit you have 03:38.880 --> 03:39.840 service. 03:39.840 --> 03:49.260 So that's what you actually want to start and you're going to use exec start and exec start is the command 03:49.260 --> 03:52.470 you want to run with the service. 03:52.470 --> 03:53.460 What is the command? 03:53.460 --> 03:54.450 We want to run. 03:54.450 --> 03:56.520 We want to run the Python script. 03:56.520 --> 04:00.750 And so I'm going to open a new terminal here. 04:01.560 --> 04:07.530 So basically we want to run Python three with our script, but here we need to give the exact command 04:07.530 --> 04:10.560 with the exact path and what do I mean by the exact path? 04:10.560 --> 04:17.850 So if you do which Python three, you can see that Python three is actually this command slash user 04:17.850 --> 04:24.540 slash bin slash python three So when you use this in the terminal, actually that's a simplification 04:24.540 --> 04:25.500 for that. 04:25.530 --> 04:32.250 So I'm just going to control shift and C and control shift and V here we're going to use Python three 04:32.250 --> 04:33.210 with. 04:33.420 --> 04:43.370 So let's do Python programs with this and how to get the correct absolute path PWD. 04:45.350 --> 04:54.830 So I'm just going to copy this here with a space slash and copy the name of. 04:55.610 --> 04:57.020 The file. 04:57.020 --> 05:03.080 So we're going to run Python three with the script with the absolute path for the command and the absolute 05:03.080 --> 05:04.970 path for the file. 05:05.210 --> 05:09.590 Then you can choose to use the user is equal to pi. 05:09.620 --> 05:14.750 So basically you're going to run this as the Pi user. 05:14.750 --> 05:18.710 So as the user you are currently connected as. 05:18.920 --> 05:19.310 Okay. 05:19.310 --> 05:22.010 So that's very important here to use the Pi user. 05:22.190 --> 05:29.210 If you don't put that, it's going to use the root user and well, I guess for this program we shouldn't 05:29.210 --> 05:30.020 have any problem. 05:30.020 --> 05:33.290 But that may give you some issues with some programs. 05:33.290 --> 05:38.840 For example, if you have relative path or file names or if you just use something that is only set 05:38.840 --> 05:42.980 up on the Pi user environment and not on the root user. 05:42.980 --> 05:45.650 So I recommend to use user is equal to pi. 05:45.650 --> 05:58.470 And then the last thing is install like this wanted by is equal to and then the same multi user dot 05:58.920 --> 05:59.580 target. 06:00.090 --> 06:00.360 Okay. 06:00.360 --> 06:02.130 And that's the complete description. 06:02.130 --> 06:06.450 That's the complete structure for the service unit service install. 06:06.480 --> 06:09.690 You can do control s control X. 06:10.380 --> 06:10.830 Okay. 06:10.830 --> 06:13.590 And now the file is going to be somewhere here. 06:13.950 --> 06:16.350 What you can do now, so let's do clear. 06:16.350 --> 06:25.710 What you can do is pseudo system Ctl with daemon reload. 06:28.960 --> 06:33.100 And then, well, what you can do if you want to just start the service. 06:33.100 --> 06:36.220 So now the service exists, but it's not going to start on boot. 06:36.250 --> 06:36.730 Okay. 06:36.730 --> 06:42.130 So I'm first going to show you how you can directly start it right now and then how you can enable it 06:42.130 --> 06:43.570 so it can start on boot. 06:43.570 --> 06:46.750 So if you want, you can do sudo system. 06:47.200 --> 06:56.080 So let's actually do CD to have more space sudo systemctl start intercom. 06:56.350 --> 07:03.970 Let's actually press tab and well it's finding the service and if I run this. 07:07.210 --> 07:09.190 You will see we have starting here. 07:09.730 --> 07:10.150 Okay. 07:10.150 --> 07:15.730 And then we have the blue led and well, the application is actually starting, but we don't have any 07:15.730 --> 07:16.240 log here. 07:16.270 --> 07:16.480 Okay. 07:16.480 --> 07:18.760 That's just the service that's going to start. 07:18.760 --> 07:27.790 But in a background process now, if you want to stop, you can do sudo systemctl stop intercom project 07:27.940 --> 07:30.280 and you stop the service. 07:30.400 --> 07:30.640 Okay. 07:30.640 --> 07:31.690 So start and stop. 07:31.720 --> 07:36.610 Allow you to just start and stop the service as you want manually. 07:36.610 --> 07:48.820 But now what you can do is so let's do sudo actually system Ctl list unit files, press enter and we 07:48.820 --> 07:51.760 have a long list. 07:52.390 --> 07:52.570 Okay. 07:52.570 --> 07:56.620 I'm just going to press Q and what we can do instead is. 07:57.850 --> 08:05.140 List unit files and then pipe grep intercom to just find what we need. 08:05.140 --> 08:09.490 And you can see we have the intercom project service which is disabled. 08:09.610 --> 08:20.770 So I'm going to do sudo systemctl enable intercom project service you can see here created similarly. 08:21.010 --> 08:21.610 ET cetera. 08:21.610 --> 08:22.420 ET cetera. 08:22.660 --> 08:26.980 If I do the list unit files you see now enabled. 08:26.980 --> 08:30.370 And so now what I'm going to do is I'm going to do sudo reboot. 08:30.400 --> 08:37.750 Let's reboot the Raspberry Pi and I'm currently on VNC so you can see it's attempting to rebooting and 08:37.750 --> 08:39.460 well, the Raspberry Pi is rebooting. 08:39.460 --> 08:40.810 You can see starting. 08:46.330 --> 08:51.880 So starting again and you can see push on button to call. 08:51.880 --> 08:59.020 So actually what happened here is that first the Arduino was powered on again and so the program started. 08:59.020 --> 09:01.120 So that was not from the Raspberry Pi. 09:01.120 --> 09:05.140 And then the service started on boot on the Raspberry Pi. 09:05.140 --> 09:11.980 And when connecting to the Arduino with Serial, this actually had the effect to reboot the Arduino. 09:11.980 --> 09:14.140 And so you saw starting again. 09:14.140 --> 09:17.290 But then the Raspberry Pi was communicating with the Arduino. 09:17.290 --> 09:23.410 And you can see now that everything is set up and we can start to just press on the push button. 09:23.410 --> 09:24.850 Please wait for a few seconds. 09:24.850 --> 09:30.430 And we have just received a notification to open or deny the access. 09:30.790 --> 09:31.270 All right. 09:31.270 --> 09:35.110 And as you see here, I have not manually launched the program. 09:35.110 --> 09:36.880 It has been launched automatically. 09:36.880 --> 09:39.430 Now, let's go back to the terminal. 09:39.700 --> 09:40.240 Okay. 09:40.240 --> 09:48.680 So if you want to stop, you can do sudo systemctl, stop intercom service. 09:48.680 --> 09:51.770 So if you want to stop it, you can do that and it's going to stop. 09:51.770 --> 09:59.750 And also now if you want to disable it, you can do sudo systemctl, disable intercom project, you 09:59.750 --> 10:12.710 can see remove this and now if you do sudo systemctl list unit files with grep intercom or just enter. 10:14.020 --> 10:17.140 When we have the intercom project, which is disabled. 10:17.620 --> 10:17.820 Okay. 10:17.860 --> 10:23.710 So you can easily start and stop with the start and stop command and then enable disable with the disable 10:23.710 --> 10:24.620 and enable command. 10:24.620 --> 10:25.510 That's very easy. 10:25.510 --> 10:31.480 And so now that it is disabled, the next time I'm going to boot the Raspberry Pi, it's not going to 10:31.480 --> 10:32.650 start the service. 10:32.680 --> 10:35.590 If I put enable, it's gonna start the service. 10:35.620 --> 10:36.160 All right. 10:36.160 --> 10:44.050 And now the project is complete so you can create the service, enable it, and then just put your Arduino 10:44.050 --> 10:47.410 and your Raspberry Pi system wherever you want. 10:47.440 --> 10:47.710 Okay. 10:47.710 --> 10:50.800 As long as the Raspberry Pi can connect to Wi-Fi, of course. 10:50.800 --> 10:56.890 And you can just leave your application, run like that and wait for notifications on your phone with 10:56.890 --> 10:58.270 the telegram application.