1 00:00:06,090 --> 00:00:07,290 Euros will burn. 2 00:00:07,290 --> 00:00:10,350 You do not know how to create a launch file, right? 3 00:00:12,240 --> 00:00:13,830 Let's solve this problem today. 4 00:00:14,310 --> 00:00:14,650 Okay. 5 00:00:14,670 --> 00:00:15,910 What is a launch file? 6 00:00:15,930 --> 00:00:23,910 It's an executable file in which we describe all our nodes that we want to run and all the configuration 7 00:00:23,910 --> 00:00:25,460 we can provide. 8 00:00:25,470 --> 00:00:31,050 And with the single command, we can launch every node and configuration. 9 00:00:35,770 --> 00:00:39,160 And now we will have to create a launch directory. 10 00:00:39,240 --> 00:00:40,210 Launch. 11 00:00:41,950 --> 00:00:42,580 Okay. 12 00:00:44,170 --> 00:00:48,370 And inside the launch, we will create a new file. 13 00:00:51,260 --> 00:00:54,830 Node underscore lounge dot bar. 14 00:00:54,920 --> 00:00:59,060 All right, so this is our lounge file. 15 00:00:59,060 --> 00:01:04,340 In order to use the lounge file, we will need to make some changes and see make list. 16 00:01:04,520 --> 00:01:09,920 We just have to add these lines inside our c make list. 17 00:01:09,950 --> 00:01:13,220 We have to declare the folder that we made. 18 00:01:13,220 --> 00:01:15,680 So we have mentioned it here. 19 00:01:15,680 --> 00:01:17,360 So just copy it. 20 00:01:17,900 --> 00:01:26,510 Come here and open the cmake list and here you can paste that line. 21 00:01:27,170 --> 00:01:29,330 All right, so that's it. 22 00:01:29,330 --> 00:01:33,380 This is what you have to make change inside the list. 23 00:01:33,380 --> 00:01:35,750 And now come to lounge file. 24 00:01:35,750 --> 00:01:41,870 And here's a piece of code copy and paste here. 25 00:01:41,900 --> 00:01:46,190 Let me explain what is it's doing here. 26 00:01:46,190 --> 00:01:52,830 We are just importing lounge and here we are importing a package and it's module actions. 27 00:01:52,830 --> 00:01:59,400 There is a function generate lounge description and which returns the lounge description inside that 28 00:01:59,400 --> 00:02:01,080 we are choosing. 29 00:02:01,080 --> 00:02:03,420 Lounge Ross Action dot Node. 30 00:02:03,450 --> 00:02:11,130 So here node is action which needs several arguments like package name, executable file and node name, 31 00:02:11,130 --> 00:02:18,780 and we will mention our arguments here and it will be launching all the information that we provided. 32 00:02:18,780 --> 00:02:28,830 Our package name is Turtle, same port and our executable is the talker. 33 00:02:28,830 --> 00:02:36,690 And if we want to change the name, we can also do that here, like launch Node. 34 00:02:38,430 --> 00:02:41,070 Okay, so this, this will be the name of the node. 35 00:02:41,100 --> 00:02:44,970 We have to build it because we have made some changes in the quake list. 36 00:02:49,580 --> 00:02:56,660 We're also launch and Turtle sim port. 37 00:02:57,080 --> 00:03:04,040 And our launch file which was the node underscore launch dot pi. 38 00:03:04,340 --> 00:03:13,190 Open up another terminal and check Ross to node list. 39 00:03:14,800 --> 00:03:19,510 Chair launch node and we can also see the topic list. 40 00:03:20,900 --> 00:03:22,040 There is our topic. 41 00:03:22,040 --> 00:03:26,210 So ros2 topic eco. 42 00:03:30,340 --> 00:03:33,190 And there we go to your receiving director. 43 00:03:33,490 --> 00:03:37,780 So can we launch the multiple nodes using the file? 44 00:03:37,810 --> 00:03:39,250 The answer is yes. 45 00:03:39,250 --> 00:03:40,970 And now you can do that. 46 00:03:41,090 --> 00:03:45,790 Will just copy this and paste it. 47 00:03:47,850 --> 00:03:48,300 Here. 48 00:03:50,740 --> 00:03:56,250 And the package will be the turtle same and the executable will be the listener. 49 00:03:58,280 --> 00:03:59,570 Let's make some changes here. 50 00:03:59,600 --> 00:04:03,890 Launch Node CPP Publisher. 51 00:04:07,040 --> 00:04:08,870 Subscriber. 52 00:04:11,420 --> 00:04:11,830 Okay. 53 00:04:11,840 --> 00:04:16,460 Now it will run both publisher and subscriber. 54 00:04:19,010 --> 00:04:20,420 If we open the. 55 00:04:24,050 --> 00:04:24,560 There you go. 56 00:04:24,800 --> 00:04:29,960 Launch North Cape Publisher and they launch North Cape Subscriber. 57 00:04:30,320 --> 00:04:31,340 There is a topic. 58 00:04:31,340 --> 00:04:32,870 We also have a Python publisher. 59 00:04:32,870 --> 00:04:34,730 We will also launch it. 60 00:04:37,640 --> 00:04:44,300 Okay, So I launched it and the refresh.