1 1 00:00:00,000 --> 00:00:03,990 In this lecture, we will be learning about how to utilize 2 2 00:00:04,000 --> 00:00:07,710 the ROS2 bridge so that we can communicate with systems 3 3 00:00:07,740 --> 00:00:08,880 running ROS1. 4 4 00:00:09,060 --> 00:00:13,380 So the first thing I'm going to do is head over to my bashrc 5 5 00:00:13,390 --> 00:00:20,930 file, which I'll edit in atom at the bottom, we should 6 6 00:00:20,940 --> 00:00:23,450 have our sources for our ROS2 installation. 7 7 00:00:23,540 --> 00:00:28,520 I'm going to go ahead and comment mines out so that no ROS 8 8 00:00:28,760 --> 00:00:29,330 is sourced. 9 9 00:00:29,900 --> 00:00:32,180 I'll go ahead and save this and close. 10 10 00:00:32,680 --> 00:00:37,420 Now, if I open a new terminal, I should be unable to use 11 11 00:00:37,430 --> 00:00:39,730 RO2 or any ROS1 commands. 12 12 00:00:43,820 --> 00:00:48,570 Now we can move on to installing ROS1 onto our system 13 13 00:00:48,580 --> 00:00:51,060 so that we can utilize the bridge here locally. 14 14 00:00:51,260 --> 00:00:55,100 So here I'm on the ROS Noetic installation page since I'm 15 15 00:00:55,110 --> 00:00:56,570 currently running Ubuntu 20. 16 16 00:00:56,660 --> 00:00:59,120 So go ahead and open up a terminal. 17 17 00:00:59,660 --> 00:01:06,720 We'll go ahead and set up our sources list, put in your password, 18 18 00:01:07,880 --> 00:01:10,410 then we'll go ahead and set up our keys. 19 19 00:01:15,040 --> 00:01:17,720 Then we'll run pseudo app update. 20 20 00:01:21,170 --> 00:01:24,000 All right, go ahead and clear the screen. 21 21 00:01:24,010 --> 00:01:27,210 And for the purposes of this video, I'm not going to install 22 22 00:01:27,220 --> 00:01:31,140 the full desktop version of ROS Noetic partly because it 23 23 00:01:31,150 --> 00:01:34,470 will also coincide with my current installations of RViz and 24 24 00:01:34,470 --> 00:01:37,230 gazebo. So instead of what I'm going to do is just simply 25 25 00:01:37,240 --> 00:01:39,900 install the base version of ROS Noetic. 26 26 00:01:39,910 --> 00:01:43,020 So this will just give me the basic packages and communication 27 27 00:01:43,030 --> 00:01:46,260 libraries, no user interface tools or anything like that. 28 28 00:01:46,470 --> 00:01:48,210 So I'll just go ahead and install this. 29 29 00:01:49,530 --> 00:01:50,460 I'll go ahead and hit 30 30 00:01:50,490 --> 00:01:50,670 yes. 31 31 00:01:52,490 --> 00:01:54,960 And so this will take a while to install. 32 32 00:01:54,970 --> 00:01:57,510 So I'll go ahead and pause the video now and we'll come back 33 33 00:01:57,520 --> 00:01:58,230 once it's finished. 34 34 00:01:58,660 --> 00:01:59,660 Alright. 35 35 00:01:59,670 --> 00:02:00,830 So the installation finished. 36 36 00:02:00,840 --> 00:02:03,290 We can just see that all it did was set up all the packages. 37 37 00:02:04,020 --> 00:02:06,540 That took about maybe four minutes for me. 38 38 00:02:06,550 --> 00:02:08,430 So that should have been too bad for you. 39 39 00:02:08,870 --> 00:02:12,300 Now we'll go ahead and move on with the environment set up 40 40 00:02:12,310 --> 00:02:12,660 of this. 41 41 00:02:12,670 --> 00:02:16,080 So in order for us to utilize our ROS1, right, we can't 42 42 00:02:16,090 --> 00:02:16,620 use anything 43 43 00:02:16,630 --> 00:02:16,770 yet. 44 44 00:02:16,780 --> 00:02:19,410 If I use roscore, which is a ROS1 command to start 45 45 00:02:19,420 --> 00:02:20,100 the ROS Master. 46 46 00:02:20,420 --> 00:02:22,940 Even though we have ROS installed, we can't use anything 47 47 00:02:22,950 --> 00:02:24,950 because we haven't set up our environment file. 48 48 00:02:25,100 --> 00:02:29,420 So if I go ahead and source my terminal environment, we should 49 49 00:02:29,430 --> 00:02:31,970 now see that I can run things like roscore. 50 50 00:02:32,320 --> 00:02:33,460 Great. 51 51 00:02:33,470 --> 00:02:37,300 So now this device has ROS1 and ROS2 installed on 52 52 00:02:37,310 --> 00:02:40,850 it. But by default, neither will be sourced on terminal startup. 53 53 00:02:41,820 --> 00:02:46,010 So the next thing we're going to do is we're going to make 54 54 00:02:46,020 --> 00:02:48,380 sure that we have all these other dependencies for building 55 55 00:02:48,390 --> 00:02:51,800 packages. So I'll go ahead and copy and paste this in. 56 56 00:02:52,240 --> 00:02:53,830 Go ahead and hit. 57 57 00:02:53,840 --> 00:02:54,490 "Y" and enter. 58 58 00:02:56,850 --> 00:03:00,820 In most cases, you already have ROS dep installed, but you 59 59 00:03:00,830 --> 00:03:05,130 can double check by pasting in this so we can see I've already 60 60 00:03:05,140 --> 00:03:06,060 have it installed. 61 61 00:03:06,480 --> 00:03:09,060 We can double check that it's initialized by running these 62 62 00:03:09,070 --> 00:03:12,880 commands. So here we can see error sources file already exists. 63 63 00:03:12,890 --> 00:03:15,340 So I'm not going to bother removing that one creating a new 64 64 00:03:15,350 --> 00:03:16,510 one. I'll just leave it as is. 65 65 00:03:17,180 --> 00:03:21,050 Okay, so now we have ROS1 and ROS2 installed and we 66 66 00:03:21,060 --> 00:03:23,720 have our extra dependencies if we have to build any packages. 67 67 00:03:23,870 --> 00:03:26,000 So for now, I'm actually going to start off clean with a 68 68 00:03:26,010 --> 00:03:28,790 new terminal environment that's not sourced on any ROS system. 69 69 00:03:28,800 --> 00:03:35,540 So now if I run ROS2 help see ROS2 command not found 70 70 00:03:35,540 --> 00:03:39,080 or roscore, and we see roscore not found. 71 71 00:03:39,090 --> 00:03:41,630 Okay, so this terminal instance can't see either one of our 72 72 00:03:41,640 --> 00:03:42,500 ROS installations. 73 73 00:03:42,770 --> 00:03:46,070 So now we'll go ahead to the ROS1 bridge documentation. 74 74 00:03:46,300 --> 00:03:48,340 Alright, so here are the prerequisites. 75 75 00:03:48,520 --> 00:03:51,340 We should have majority of these prerequisites from the basic 76 76 00:03:51,350 --> 00:03:54,790 installation. But first off, I'll go ahead and source the 77 77 00:03:54,800 --> 00:03:57,490 ROS1 installation, as these are catered towards the ROS1 78 78 00:03:57,490 --> 00:03:58,360 installation. 79 79 00:03:58,720 --> 00:04:04,470 So I'll do source/opt/ros/noetic. 80 80 00:04:04,480 --> 00:04:04,980 --- 81 81 00:04:07,680 --> 00:04:11,250 And so now I should have access to my tools like roscore 82 82 00:04:11,640 --> 00:04:13,080 and we can see I do. 83 83 00:04:13,770 --> 00:04:16,470 Now I'll just make sure that I have all these other packages 84 84 00:04:16,480 --> 00:04:19,880 installed, which I can do using pseudo apt install. 85 85 00:04:20,740 --> 00:04:24,590 And then we do ROS the name of the distribution which in 86 86 00:04:24,600 --> 00:04:26,270 this case for me is Noetic. 87 87 00:04:26,780 --> 00:04:28,580 And then the name of the package. 88 88 00:04:28,590 --> 00:04:33,170 So things like catkin, roscpp, roslaunch, rosmsg 89 89 00:04:33,180 --> 00:04:35,960 should all be already installed because that comes with the 90 90 00:04:35,970 --> 00:04:36,800 basic installation. 91 91 00:04:36,800 --> 00:04:39,920 The main things we're going to be missing though, are going 92 92 00:04:39,930 --> 00:04:42,950 to be those that are utilized for the examples including 93 93 00:04:42,960 --> 00:04:45,500 the tutorials and the RQT image view. 94 94 00:04:45,680 --> 00:04:48,350 So I can go ahead and install those specifically. 95 95 00:04:50,990 --> 00:04:54,810 And note instead of using underscores when using the pseudo 96 96 00:04:54,820 --> 00:04:58,110 apt command, you should use just a simple dash when you see 97 97 00:04:58,120 --> 00:05:00,270 the package name separated by underscores. 98 98 00:05:02,490 --> 00:05:05,550 So as you can see here, instead of doing roscpy_tutorials 99 99 00:05:05,560 --> 00:05:10,410 I am doing roscpy-tutorials, but that correlates 100 100 00:05:10,420 --> 00:05:11,430 to the correct package. 101 101 00:05:13,360 --> 00:05:17,210 And then last but not least, I'll install the RQT image view. 102 102 00:05:24,330 --> 00:05:25,330 Alright. 103 103 00:05:25,330 --> 00:05:27,250 And we should be good to go on that front. 104 104 00:05:27,260 --> 00:05:29,830 You can double check with all the other packages that you 105 105 00:05:29,840 --> 00:05:31,060 have them properly installed. 106 106 00:05:31,990 --> 00:05:33,110 Moving on. 107 107 00:05:33,120 --> 00:05:35,180 We can go on to building the bridge from source. 108 108 00:05:35,780 --> 00:05:38,810 So earlier we installed ROS2 from source. 109 109 00:05:39,080 --> 00:05:42,110 And so in order to utilize it, we actually have to make sure 110 110 00:05:42,120 --> 00:05:45,340 that we skip the ROS1 bridge command on build initially. 111 111 00:05:45,350 --> 00:05:47,980 So I'll go ahead and do that now in a new terminal. 112 112 00:06:03,560 --> 00:06:07,190 So here you are seeing we're rebuilding the ROS2 installation, 113 113 00:06:07,310 --> 00:06:10,160 but this should go by a lot faster since we've already built 114 114 00:06:10,170 --> 00:06:10,730 it already. 115 115 00:06:10,910 --> 00:06:13,820 This time we're just simply skipping the ROS1 bridge. 116 116 00:06:14,060 --> 00:06:16,280 That took 20 minutes or so. 117 117 00:06:16,290 --> 00:06:19,910 We did have some standard error outputs from RQT, GUI and 118 118 00:06:19,920 --> 00:06:21,290 RM Connect. 119 119 00:06:21,470 --> 00:06:24,140 I'm not going to be using Connect and I don't plan on using 120 120 00:06:24,150 --> 00:06:27,200 the RQT Gui, so I don't think this will affect us for right 121 121 00:06:27,210 --> 00:06:31,340 now. So I'm just going to continue on with the read me documentation 122 122 00:06:31,350 --> 00:06:32,930 for utilizing the ROS bridge. 123 123 00:06:33,180 --> 00:06:36,930 So now we need to source our ROS1 environment. 124 124 00:06:37,680 --> 00:06:44,640 We will do source/opt/ros/noetic/setup.bash 125 125 00:06:44,650 --> 00:06:53,700 ROS2 installation which is located here in my 126 126 00:06:53,710 --> 00:06:54,720 workspace directory. 127 127 00:06:54,720 --> 00:06:58,110 So I'll do source install setup bash. 128 128 00:07:00,490 --> 00:07:04,460 So I'll mention that the distribution was Noetic before. 129 129 00:07:04,850 --> 00:07:07,310 That's fine, because that's what indeed we were doing. 130 130 00:07:07,320 --> 00:07:10,370 We had our ROS1 source, and then now we just source our 131 131 00:07:10,380 --> 00:07:11,570 ROS Fox installation. 132 132 00:07:11,930 --> 00:07:16,190 Now we can build the ROS1 bridge using this command. 133 133 00:07:17,410 --> 00:07:22,280 So this will only rebuild the ROS1 bridge package so 134 134 00:07:22,290 --> 00:07:24,950 it won't rebuild the whole ROS2 installation. 135 135 00:07:24,960 --> 00:07:26,270 So we'll go ahead and run this. 136 136 00:07:28,710 --> 00:07:29,710 Alright. 137 137 00:07:29,720 --> 00:07:31,630 So our ROS1 bridge finished building. 138 138 00:07:31,640 --> 00:07:33,280 That took about eight minutes for me. 139 139 00:07:33,880 --> 00:07:36,910 So I we'll go through and try to run some examples. 140 140 00:07:37,120 --> 00:07:42,370 So I'll go ahead and open up new terminals that are independent 141 141 00:07:42,380 --> 00:07:44,200 of this one, since this one has both of them. 142 142 00:07:44,210 --> 00:07:46,570 sourced, I'll put this one away. 143 143 00:07:46,660 --> 00:07:50,950 So the first one I'll do is source this terminal to have 144 144 00:07:50,960 --> 00:07:54,250 only ROS1 to imitate my previous robot or system which 145 145 00:07:54,260 --> 00:08:00,670 only ran ROS1 code, such as sources opt ROS noetic 146 146 00:08:01,240 --> 00:08:02,590 setup.bash 147 147 00:08:05,930 --> 00:08:08,910 And then we'll just run a roscore instance. 148 148 00:08:10,380 --> 00:08:13,840 Then for this example, we'll need another shell which has 149 149 00:08:13,850 --> 00:08:17,220 ROS1 and then ROS2 source, which pretty much makes 150 150 00:08:17,230 --> 00:08:19,410 up the previous terminal we had and did our installation. 151 151 00:08:19,420 --> 00:08:20,790 So I'm going to bring that one back. 152 152 00:08:22,660 --> 00:08:26,540 And what we're going to do is export the ROS Master URI 153 153 00:08:26,660 --> 00:08:30,620 to match that of the local host or in this case, what this 154 154 00:08:30,630 --> 00:08:31,520 URI should be. 155 155 00:08:31,720 --> 00:08:34,960 So we can go ahead and export that. 156 156 00:08:35,419 --> 00:08:38,659 And now we can try run the ROS2 bridge. 157 157 00:08:41,039 --> 00:08:42,179 Alright. 158 158 00:08:42,190 --> 00:08:45,000 So here we can see that it created a bridge for the ROS 159 159 00:08:45,030 --> 00:08:46,950 out and RCL interface tags. 160 160 00:08:47,180 --> 00:08:49,610 Here I go and open a new terminal tab. 161 161 00:08:50,120 --> 00:08:55,670 Source opt ROS Noetic, setup.bash ROS topic list. 162 162 00:08:56,160 --> 00:08:57,180 All right. 163 163 00:08:57,190 --> 00:09:00,720 So we see that it converted our ROS out from ROS1, to ROS2 164 164 00:09:00,730 --> 00:09:03,720 Alright, so now we can go ahead and actually start some 165 165 00:09:03,730 --> 00:09:06,780 notes. For this example, we'll need another terminal which 166 166 00:09:06,790 --> 00:09:09,390 has our ROS1 source, which I just did here. 167 167 00:09:09,560 --> 00:09:12,650 I should go ahead and clear the screen and we'll go ahead 168 168 00:09:12,650 --> 00:09:15,350 and run talker node from the tutorials. 169 169 00:09:15,660 --> 00:09:20,700 So here we see these "Hello Worlds" publishing out. 170 170 00:09:20,700 --> 00:09:24,300 And now I can go ahead and open up another ROS2 instance. 171 171 00:09:24,310 --> 00:09:25,920 So this one has our ROS bridge running. 172 172 00:09:25,930 --> 00:09:29,210 So I'm going to open up another terminal tab and I'm going 173 173 00:09:29,220 --> 00:09:34,100 to source our install setup bash file. 174 174 00:09:35,990 --> 00:09:38,910 And then we can do our listener node. 175 175 00:09:39,100 --> 00:09:40,120 Okay. 176 176 00:09:43,050 --> 00:09:46,450 And here we can see we are receiving the "Hello World" messages 177 177 00:09:46,630 --> 00:09:47,800 from ROS version one. 178 178 00:09:47,810 --> 00:09:50,490 In this case, Noetic ROS2 Foxy. 179 179 00:09:51,780 --> 00:09:53,100 So there you go. 180 180 00:09:53,110 --> 00:09:56,360 That's how you can utilize the ROS bridge to bridge over 181 181 00:09:56,360 --> 00:10:00,200 perhaps old nodes that you had made in ROS1, and then 182 182 00:10:00,210 --> 00:10:02,390 you can implement them into ROS2 nodes. 183 183 00:10:02,880 --> 00:10:04,230 I'll go ahead and stop these. 184 184 00:10:08,560 --> 00:10:09,680 That's it. 185 185 00:10:09,690 --> 00:10:12,050 For this part of the video, I will do a second part of the 186 186 00:10:12,060 --> 00:10:16,050 video where I will do cross device communication using the 187 187 00:10:16,060 --> 00:10:16,590 ROS bridge. 188 188 00:10:18,060 --> 00:10:19,780 Alright, so here we are. 189 189 00:10:19,790 --> 00:10:22,900 I have two different computers going right now that are connected 190 190 00:10:22,910 --> 00:10:25,150 to each other via an Ethernet switch. 191 191 00:10:25,460 --> 00:10:29,720 So the first one is our original computer, which is running 192 192 00:10:29,730 --> 00:10:33,740 our ubuntu 20, where we have our ROS2 Foxy installed 193 193 00:10:33,750 --> 00:10:34,790 as well as ROS1. 194 194 00:10:34,800 --> 00:10:38,350 Noetic, on the second computer, we have a laptop of mine 195 195 00:10:38,360 --> 00:10:40,030 that's running Ubuntu 18. 196 196 00:10:40,240 --> 00:10:42,010 And this one is running ROS Melodic. 197 197 00:10:42,040 --> 00:10:44,980 So starting off with my laptop, I can go ahead and open up 198 198 00:10:44,990 --> 00:10:46,750 a terminal here just to show this to you. 199 199 00:10:46,760 --> 00:10:51,990 If I go over and do ROS version -d, as you can see, I'm running 200 200 00:10:52,000 --> 00:10:56,540 Melodic. And if I were to do ROS2 help, you can see that 201 201 00:10:56,550 --> 00:10:58,070 I do not have ROS2 install. 202 202 00:10:58,520 --> 00:11:01,100 All right, so that's the first thing to note. 203 203 00:11:01,110 --> 00:11:03,740 The second thing to note when working with two different 204 204 00:11:03,750 --> 00:11:06,230 systems is that each one will have its own independent IP 205 205 00:11:06,290 --> 00:11:09,710 address, either by you setting it or by a router setting 206 206 00:11:09,720 --> 00:11:13,550 it. So I can check that by running the IF Config command. 207 207 00:11:13,700 --> 00:11:18,040 And so here we can see my IP address for this computer is 208 208 00:11:18,160 --> 00:11:25,120 192.168.50.177, so all my other local computers that are 209 209 00:11:25,130 --> 00:11:29,090 on this network can't communicate with this computer by locating 210 210 00:11:29,100 --> 00:11:30,260 this IP address. 211 211 00:11:30,440 --> 00:11:34,370 So we can do the same thing over here on my Ubuntu 20 machine. 212 212 00:11:34,380 --> 00:11:38,690 So if I go over here and I type in If Config, you can see 213 213 00:11:38,700 --> 00:11:45,160 this machine has an IP address of 192.168.50.3 214 214 00:11:45,490 --> 00:11:48,850 So be wary of what your machines IP addresses are, because 215 215 00:11:48,860 --> 00:11:51,730 they will vary from mine if you are trying to reproduce what 216 216 00:11:51,740 --> 00:11:52,660 I'm about to do here. 217 217 00:11:52,700 --> 00:11:53,660 All right. 218 218 00:11:53,670 --> 00:11:57,440 So heading back to my machine running Ubuntu 18, I can go 219 219 00:11:57,450 --> 00:11:58,670 ahead and clear the screen. 220 220 00:11:58,670 --> 00:12:00,740 So this will be running our ROS1 instance. 221 221 00:12:00,750 --> 00:12:03,500 And we'll be simulating essentially that this is one of our 222 222 00:12:03,510 --> 00:12:05,120 robots running a ROS1 node. 223 223 00:12:05,130 --> 00:12:07,880 And then we want our Ubuntu 20 machine which has ROS2 224 224 00:12:07,890 --> 00:12:10,580 and ROS1 installed to be able to communicate with this 225 225 00:12:10,590 --> 00:12:13,400 one. And so we don't want to have to install ROS2 in this 226 226 00:12:13,410 --> 00:12:15,350 machine. So we're going to go through how we can go about 227 227 00:12:15,360 --> 00:12:15,740 doing that. 228 228 00:12:15,750 --> 00:12:18,650 If we have an older robot that we developed code for, we 229 229 00:12:18,660 --> 00:12:22,160 can still utilize it with newer machines that run ROS2. 230 230 00:12:22,600 --> 00:12:25,960 So the first thing to note, whenever we're dealing with ROS 231 231 00:12:25,960 --> 00:12:30,490 networking, we have to set ROS master URI and the ROS IP 232 232 00:12:30,550 --> 00:12:31,180 of the device. 233 233 00:12:31,190 --> 00:12:33,250 So I've gone ahead and listed these down. 234 234 00:12:33,250 --> 00:12:33,520 Right. 235 235 00:12:33,530 --> 00:12:36,520 So we just took note of the IP address, and I'll put it back 236 236 00:12:36,530 --> 00:12:37,000 up on here. 237 237 00:12:37,010 --> 00:12:37,990 IF config. 238 238 00:12:38,140 --> 00:12:42,430 All right, so this one is 192.168.50.177 239 239 00:12:42,580 --> 00:12:46,570 So in ROS1, there was a central ROS Master server, which 240 240 00:12:46,580 --> 00:12:48,730 all the ROS nodes would have to communicate with. 241 241 00:12:48,740 --> 00:12:51,040 I will have that set running on this computer. 242 242 00:12:51,280 --> 00:12:56,160 So what I will do is set my ROS Master URI by using the 243 243 00:12:56,170 --> 00:13:00,960 export command, and I will set it to all set up to https 244 244 00:13:01,740 --> 00:13:06,680 this IP address, and then Port 11 3 11, which is a default 245 245 00:13:06,680 --> 00:13:08,240 Port ROS1 runs off of. 246 246 00:13:08,260 --> 00:13:10,090 So I'll go ahead and run that. 247 247 00:13:10,100 --> 00:13:14,230 Then I'm going to set the ROS IP of this particular device, 248 248 00:13:14,740 --> 00:13:17,140 which is just the IP address part. 249 249 00:13:17,150 --> 00:13:20,380 So you don't need the Http, and you don't need the Port number 250 250 00:13:20,390 --> 00:13:21,130 at the end of it. 251 251 00:13:21,140 --> 00:13:25,270 And so with that, now, this knows that the ROS Master should 252 252 00:13:25,280 --> 00:13:28,900 be running on this machine on Port 11 3 11, because this 253 253 00:13:28,910 --> 00:13:31,180 is the machine with this particular IP address. 254 254 00:13:31,760 --> 00:13:35,540 So now we can go ahead and start our ROS Master for ROS 255 255 00:13:35,550 --> 00:13:36,920 one using ROS Core. 256 256 00:13:37,840 --> 00:13:41,090 Okay, so now we have a roscore instance running. 257 257 00:13:41,100 --> 00:13:42,620 So our ROS Melodic is running. 258 258 00:13:42,840 --> 00:13:46,080 So now if we go over to our one to 20 machine, we can run 259 259 00:13:46,090 --> 00:13:48,840 through the first example from the ROS1 bridge documentation 260 260 00:13:48,850 --> 00:13:49,980 in a very similar way. 261 261 00:13:50,280 --> 00:13:54,470 So right now, our shell A, which is ROS1 only, is that 262 262 00:13:54,480 --> 00:13:57,200 Ubuntu 18 computer that I just ran roscore on. 263 263 00:13:57,360 --> 00:14:00,270 So that only has ROS Melodic on it, and it's now running 264 264 00:14:00,280 --> 00:14:00,840 roscore. 265 265 00:14:01,350 --> 00:14:03,870 So now this will be our shell B. 266 266 00:14:03,880 --> 00:14:05,460 So we first source ROS1. 267 267 00:14:05,460 --> 00:14:08,100 In this case, I don't have melodic, but I have Noetic, but 268 268 00:14:08,110 --> 00:14:10,350 this will still work, even though it's a different distribution. 269 269 00:14:10,360 --> 00:14:14,090 So if I go ahead and run this source command right here, 270 270 00:14:14,100 --> 00:14:17,570 I am sourcing my Noetic setup bash where I installed it. 271 271 00:14:17,580 --> 00:14:21,500 Okay, so now my ROS Noetic is sourced for this terminal. 272 272 00:14:21,510 --> 00:14:24,740 Then we'll go ahead and source our ROS2 instance, which 273 273 00:14:24,750 --> 00:14:28,100 I also have here because I built ROS2 from source. 274 274 00:14:28,110 --> 00:14:31,610 So I have it here in my workspace folder, ROS2 Foxy, and 275 275 00:14:31,620 --> 00:14:33,020 then install setup bash. 276 276 00:14:33,300 --> 00:14:36,690 And so we got a little warning here saying set to Noetic 277 277 00:14:36,700 --> 00:14:37,680 before, please make sure. 278 278 00:14:37,690 --> 00:14:38,820 But that's totally fine. 279 279 00:14:38,830 --> 00:14:40,680 So for now, I'm just going to clear the screen. 280 280 00:14:40,840 --> 00:14:46,270 And now we need to export the ROS Master URI and our ROS 281 281 00:14:46,300 --> 00:14:48,610 IP address to match what it's supposed to be. 282 282 00:14:48,610 --> 00:14:52,090 So first off, we'll set the ROS Master URI. 283 283 00:14:52,090 --> 00:14:54,550 So the same thing we just set it to on the other computer. 284 284 00:14:54,560 --> 00:14:54,790 Right. 285 285 00:14:54,800 --> 00:14:58,250 So the ROS Master is running on the open to 18 computer, 286 286 00:14:58,520 --> 00:14:59,990 which has this IP address. 287 287 00:15:00,000 --> 00:15:02,870 So this will be our Master URI we want to communicate with. 288 288 00:15:02,880 --> 00:15:05,570 And then, as we mentioned, if I type in is config. 289 289 00:15:06,170 --> 00:15:06,410 Right. 290 290 00:15:06,660 --> 00:15:09,600 This is the IP address for this specific computer. 291 291 00:15:09,610 --> 00:15:13,530 So I'm going to export the ROS IP variable here in my terminal 292 292 00:15:13,660 --> 00:15:16,900 so that it knows that this is the ROS IP of this machine. 293 293 00:15:17,380 --> 00:15:19,840 Cool that I can go ahead and clear the screen. 294 294 00:15:19,840 --> 00:15:22,780 And now we can run ROS bridge. 295 295 00:15:23,620 --> 00:15:26,860 So if I go ahead and run this ROS2 run ROS1 bridge 296 296 00:15:27,220 --> 00:15:31,180 dynamic bridge, you can go ahead and run it, and you can 297 297 00:15:31,190 --> 00:15:34,000 see it created the bridge, and it's already beginning to 298 298 00:15:34,010 --> 00:15:35,140 convert those messages. 299 299 00:15:35,650 --> 00:15:39,940 Now we can actually open up another terminal to follow through 300 300 00:15:39,950 --> 00:15:40,660 with this example. 301 301 00:15:40,670 --> 00:15:43,360 And we will open this up on our Ubuntu 18 machine. 302 302 00:15:43,370 --> 00:15:45,430 And this will be our talker note that comes with just the 303 303 00:15:45,440 --> 00:15:47,500 normal ROS Py tutorials for ROS1. 304 304 00:15:47,940 --> 00:15:50,010 So I'll go ahead and do that now. 305 305 00:15:50,020 --> 00:15:51,120 So I'll control alt T. 306 306 00:15:51,150 --> 00:15:53,310 So now I have a new terminal here. 307 307 00:15:53,520 --> 00:15:56,010 And just to make sure again, just to prove to you that this 308 308 00:15:56,020 --> 00:15:57,600 is only source with this ROS melodic. 309 309 00:15:57,610 --> 00:16:02,600 If I do, ROS version -d it says melodic. ROS2 help. 310 310 00:16:02,720 --> 00:16:05,510 And you can see I don't have ROS2 installed on this machine, 311 311 00:16:05,520 --> 00:16:07,220 so I'm not trying to pull anything here. 312 312 00:16:07,230 --> 00:16:09,440 This machine only has ROS1 on it. 313 313 00:16:09,800 --> 00:16:13,790 We will need to make sure, though, that we have our Master 314 314 00:16:13,790 --> 00:16:17,630 URI and IP properly set in every terminal. 315 315 00:16:17,640 --> 00:16:20,600 So normally you would set this in your bash RC file so that 316 316 00:16:20,610 --> 00:16:22,340 it runs every time you open a new terminal. 317 317 00:16:22,520 --> 00:16:24,950 But for right now, I'm just going to set this manually. 318 318 00:16:24,960 --> 00:16:27,500 Each time we open a new terminal, we will only be opening 319 319 00:16:27,510 --> 00:16:28,100 these terminals. 320 320 00:16:28,110 --> 00:16:28,970 This should be fine. 321 321 00:16:29,180 --> 00:16:32,210 And now we can go ahead and run our talker node. 322 322 00:16:32,500 --> 00:16:37,390 So here we can see the default Hello World messages are pointing 323 323 00:16:37,400 --> 00:16:38,050 to the screen. 324 324 00:16:38,290 --> 00:16:43,580 Now, if I go back to my ubuntu 20 machine, I can open up another 325 325 00:16:43,590 --> 00:16:46,220 shell that only needs to have ROS2 sourced on it. 326 326 00:16:46,230 --> 00:16:47,510 So I'll go ahead and do control alt T. 327 327 00:16:48,060 --> 00:16:50,010 And here's my second instance. 328 328 00:16:50,020 --> 00:17:00,390 And so I will source my ROS Foxy install, and we don't have 329 329 00:17:00,400 --> 00:17:01,440 to worry about the warning. 330 330 00:17:01,450 --> 00:17:04,140 And then if now I go ahead and run a listener. 331 331 00:17:04,150 --> 00:17:04,710 Right. 332 332 00:17:04,829 --> 00:17:07,530 So there are no talker nodes running on this machine the 333 333 00:17:07,540 --> 00:17:10,349 only talker node is running on the Ubuntu 18 machine. 334 334 00:17:10,800 --> 00:17:13,920 But because we have our bridge running here, we should be 335 335 00:17:13,930 --> 00:17:17,180 able to listen in on those messages over the network, because 336 336 00:17:17,190 --> 00:17:20,510 we set our ROS Master URI and our ROS IP address accordingly. 337 337 00:17:20,750 --> 00:17:24,369 Actually, that's actually what I need to do here. 338 338 00:17:24,380 --> 00:17:27,730 So before I go ahead and run that, I will need to set our 339 339 00:17:27,740 --> 00:17:31,180 ROS Master URI and our ROS IP in this terminal, since this 340 340 00:17:31,190 --> 00:17:33,840 is a new terminal, alright 341 341 00:17:33,870 --> 00:17:36,240 With that, now I can go ahead and run the listener. 342 342 00:17:38,790 --> 00:17:42,430 And here you can see the ROS bridge detects that message 343 343 00:17:42,490 --> 00:17:46,240 coming from the ROS2, and the ROS1 it bridges it. 344 344 00:17:46,250 --> 00:17:48,790 And here we can see I heard Hello World, which is matching 345 345 00:17:48,800 --> 00:17:52,310 with what is being sent from the Ubuntu 18 computer. 346 346 00:17:53,060 --> 00:17:53,360 Cool! 347 347 00:17:53,690 --> 00:17:55,850 And it's worth noting that this works both ways. 348 348 00:17:55,860 --> 00:17:58,220 So I'll go ahead and stop this listener node, and I'll stop 349 349 00:17:58,230 --> 00:17:59,570 the talker node on the other machine. 350 350 00:17:59,580 --> 00:18:02,720 I'll go ahead and clear the screen on both of these. 351 351 00:18:03,140 --> 00:18:05,750 But this also works from ROS2 to ROS1. 352 352 00:18:05,760 --> 00:18:08,930 So if you create any new nodes on your ROS2 instance 353 353 00:18:08,940 --> 00:18:11,980 that you want your ROS1 computer to Subscribe to, it 354 354 00:18:12,040 --> 00:18:13,000 works the same way. 355 355 00:18:13,010 --> 00:18:16,090 Instead of running the listener node this time, I can run 356 356 00:18:16,100 --> 00:18:16,960 the talker node. 357 357 00:18:18,190 --> 00:18:24,140 So if we say talker, we can see we're publishing Hello World. 358 358 00:18:24,150 --> 00:18:25,280 And then counter variable. 359 359 00:18:25,290 --> 00:18:27,860 That's what this version of talker looks like for ROS2. 360 360 00:18:28,280 --> 00:18:32,600 And now if I run the listener node on our own to 18 machine 361 361 00:18:33,020 --> 00:18:37,430 that is running only ROS1 the ROS bridge will show up, 362 362 00:18:37,440 --> 00:18:38,960 that it's bridging the communications. 363 363 00:18:38,970 --> 00:18:42,290 And we can see here that my ROS2 publishing Hello World 364 364 00:18:42,320 --> 00:18:45,280 is being received on my ROS1 machine, and it's receiving 365 365 00:18:45,290 --> 00:18:47,500 the Hello World messages just fine on the listener node. 366 366 00:18:47,500 --> 00:18:49,810 I can go ahead and stop this node. 367 367 00:18:50,500 --> 00:18:54,070 With that, you have successfully implemented use of the ROS2 368 368 00:18:54,070 --> 00:18:57,010 bridge so that you could bridge communications between 369 369 00:18:57,020 --> 00:18:59,080 ROS1 and ROS2 systems.