1 00:00:05,450 --> 00:00:11,060 Now we are going to write the code for the subscriber and we are not going to write. 2 00:00:11,300 --> 00:00:12,920 Someone else is going to write. 3 00:00:13,540 --> 00:00:14,960 Yeah, this chibitty. 4 00:00:15,740 --> 00:00:18,800 You can use Chat Liberty to write your code. 5 00:00:18,850 --> 00:00:21,890 You can get rid of this struggle of writing the code. 6 00:00:21,890 --> 00:00:25,850 You can just tell chettipatti and get what you want. 7 00:00:26,420 --> 00:00:27,830 Okay, we will do that. 8 00:00:27,860 --> 00:00:40,310 We will say to church to write the rows to ship string subscriber or cord hit enter. 9 00:00:50,060 --> 00:00:56,510 The one thing that you need to understand about our subscriber subscriber will be called whenever it 10 00:00:56,510 --> 00:01:03,050 receives data and there will be a callback function that will be called whenever the subscriber receives 11 00:01:03,050 --> 00:01:03,770 the data. 12 00:01:03,770 --> 00:01:08,000 And then you can do your further processing. 13 00:01:08,000 --> 00:01:10,340 So it has provided us the code. 14 00:01:10,370 --> 00:01:18,140 We will use this to open up our VS code in which we have already publisher and my node dot cpp file. 15 00:01:18,140 --> 00:01:29,510 We will just create another one new file subscriber dot js We have this and we will just copy and paste 16 00:01:29,510 --> 00:01:30,350 it here. 17 00:01:31,730 --> 00:01:32,200 All right. 18 00:01:32,210 --> 00:01:36,920 It has created the subscriber with a similar fashion, except you can see it here. 19 00:01:36,920 --> 00:01:44,360 Instead of using Create publisher, it has issues create subscriber and there is a callback function 20 00:01:44,360 --> 00:01:47,360 to string callback that is declared here. 21 00:01:47,390 --> 00:01:56,220 If this is just printing the information, explain the code line by line. 22 00:01:56,970 --> 00:02:01,830 It is going to solve all the problems that you can possibly have with the code. 23 00:02:03,240 --> 00:02:04,980 And there you go. 24 00:02:04,980 --> 00:02:06,900 It will explain everything. 25 00:02:07,020 --> 00:02:11,610 So we have our subscriber code here, but we cannot use it. 26 00:02:11,640 --> 00:02:12,150 Why? 27 00:02:12,660 --> 00:02:18,570 Because we have to tell that we have created a node to the package. 28 00:02:18,570 --> 00:02:24,270 How we do that, we mention it in package XML file and cmakelists. 29 00:02:24,960 --> 00:02:25,410 Okay. 30 00:02:25,410 --> 00:02:28,860 And the package XML will declare the dependencies. 31 00:02:28,860 --> 00:02:35,940 So it is dependent on the messages that we have already declared. 32 00:02:35,940 --> 00:02:36,870 So that's it. 33 00:02:36,870 --> 00:02:43,740 We will not edit anything in the package XML file, but we will go to the cmake list and there we will 34 00:02:43,740 --> 00:02:45,120 add a node. 35 00:02:46,170 --> 00:02:48,930 So we will just copy it here. 36 00:02:53,190 --> 00:02:53,790 First it. 37 00:02:55,980 --> 00:02:57,840 Fuel cell listener. 38 00:03:02,610 --> 00:03:09,060 And then the pot is a shark and the file name is subscriber. 39 00:03:12,070 --> 00:03:13,480 Listener Nordeney. 40 00:03:14,110 --> 00:03:18,250 And it depends on our messages. 41 00:03:18,280 --> 00:03:24,820 In the installed, we will just write the name of the node, which is listener. 42 00:03:30,220 --> 00:03:30,690 Yes. 43 00:03:31,050 --> 00:03:33,240 And now we will try to build it. 44 00:03:35,830 --> 00:03:36,850 The court is filled. 45 00:03:39,550 --> 00:03:40,030 Source. 46 00:03:40,420 --> 00:03:43,150 Install local setup source workspace. 47 00:03:43,150 --> 00:03:48,430 And now we will run the subscriber ros to run turtle. 48 00:03:48,700 --> 00:03:52,420 Same for and press double tab. 49 00:03:53,170 --> 00:04:01,480 Now it is offering three nodes so we will just write listener and hit enter. 50 00:04:02,320 --> 00:04:06,700 So now the node is running and we will see Ros topic. 51 00:04:08,350 --> 00:04:10,570 And now we see there is our topic. 52 00:04:10,600 --> 00:04:12,280 Today's topic name. 53 00:04:12,280 --> 00:04:14,770 And this is our the name of the subscriber. 54 00:04:14,770 --> 00:04:19,570 But in the publisher the topic name was just topic. 55 00:04:19,600 --> 00:04:26,500 We will just try to modify both of the topics and we will give them a common name in order to set their 56 00:04:26,500 --> 00:04:27,460 communication. 57 00:04:27,820 --> 00:04:35,650 Remember, if we want a publisher and subscriber communicate, there should be a common topic with the 58 00:04:35,650 --> 00:04:36,400 same name. 59 00:04:36,400 --> 00:04:38,470 Okay, come here to the publisher. 60 00:04:38,470 --> 00:04:41,800 And there is the topic, which is topic trained. 61 00:04:46,810 --> 00:04:48,050 Message. 62 00:04:50,180 --> 00:04:53,400 Commission me question. 63 00:04:54,470 --> 00:04:57,500 Okay, so this is our topic name. 64 00:04:57,500 --> 00:05:00,290 Now save it. 65 00:05:00,290 --> 00:05:01,970 And also come here. 66 00:05:01,970 --> 00:05:04,790 And this is the subscriber topic. 67 00:05:05,480 --> 00:05:08,150 Okay, so now we will build it again. 68 00:05:11,400 --> 00:05:15,030 And now we will run our subscriber. 69 00:05:15,870 --> 00:05:19,560 And now we will check the name of the topic. 70 00:05:20,130 --> 00:05:21,540 And there we go. 71 00:05:21,780 --> 00:05:23,550 String message communication. 72 00:05:23,700 --> 00:05:29,340 Okay, So currently it is not showing any data because there is no publisher. 73 00:05:29,340 --> 00:05:38,040 But we are going to we will just open another terminal source, install local setup dot bash. 74 00:05:38,460 --> 00:05:44,760 And now the terminal is sourced and it knows we have a workspace called Ros Workspace. 75 00:05:44,970 --> 00:05:51,960 And now we will run the Ros to run turtle same port. 76 00:05:52,200 --> 00:05:59,910 And then the publisher, which was Docker and it is publishing the data, hopefully. 77 00:05:59,910 --> 00:06:01,550 And there you go. 78 00:06:01,560 --> 00:06:02,190 It is. 79 00:06:02,780 --> 00:06:05,510 And we can also check it from here. 80 00:06:05,820 --> 00:06:09,980 Rose to topic equal. 81 00:06:12,120 --> 00:06:16,650 Topping name, and it is also receiving the data here. 82 00:06:17,310 --> 00:06:17,850 Okay. 83 00:06:18,240 --> 00:06:21,010 And press control C to kill it. 84 00:06:21,030 --> 00:06:25,740 And now we will see the connection using our equity graph. 85 00:06:25,990 --> 00:06:28,620 Arc underscore graph. 86 00:06:36,930 --> 00:06:37,310 Okay. 87 00:06:37,320 --> 00:06:38,610 The notes are minimal. 88 00:06:38,610 --> 00:06:43,680 Publisher and the string subscriber and the topic name is String message communication.