WEBVTT 00:00.080 --> 00:06.590 In this new activity, you are going to control your Arduino from Telegram and of course, going through 00:06.590 --> 00:07.670 the Raspberry Pi. 00:07.700 --> 00:13.940 So basically what you have to do is so when you're going to send some comments from the chat, so you're 00:13.940 --> 00:17.420 going to control the RGB led and the LCD screen. 00:17.420 --> 00:24.770 So for example, you type slash LCD, that's going to be the command and then some text, okay, you're 00:24.770 --> 00:25.670 going to type this. 00:25.670 --> 00:27.260 So for now it doesn't do anything. 00:27.260 --> 00:34.640 And this text here should appear on the LCD screen and also a command for the RGB led. 00:35.270 --> 00:35.540 Okay. 00:35.540 --> 00:38.120 So now we arrive at things a little bit more complex. 00:38.120 --> 00:42.530 But again, if you have correctly understood the following, it should not be a problem. 00:42.530 --> 00:44.180 You can manage to do it by yourself. 00:44.180 --> 00:52.610 So on the Arduino side, what you're going to do is just open and handle comments for RGB Led and LCD 00:52.610 --> 00:53.180 screen. 00:53.180 --> 00:56.990 So for the LCD screen, I will let you define a protocol. 00:56.990 --> 01:03.320 So what kind of comment you can send from what we have done before, you should be able to do that. 01:03.320 --> 01:09.140 And for the RGB led, what we have done previously was to set each color independently. 01:09.140 --> 01:12.860 Okay, you would send red, you would send green and you would send blue. 01:12.890 --> 01:19.490 Here we are going to improve a little bit and instead of sending green, blue, red, we are going to 01:19.490 --> 01:22.280 just send one comment for the three colors. 01:22.310 --> 01:22.940 Okay. 01:23.120 --> 01:25.520 And here I have shown you an example. 01:25.520 --> 01:26.060 Okay. 01:26.600 --> 01:28.100 Actually, let's use comma. 01:29.660 --> 01:36.530 So we have the command set led like this and then we have three numbers. 01:36.530 --> 01:39.080 So this is going to be sent as a string, of course. 01:39.290 --> 01:45.080 And so you check that the command starts with set Led, you remove the first one, two, three, four, 01:45.080 --> 01:48.950 five, six, seven, eight characters and then you are left with this. 01:49.280 --> 01:54.920 And then you have the substring function that you can use on the string on the Arduino string. 01:55.130 --> 01:55.310 Okay. 01:55.310 --> 01:58.070 To just get one part of the string. 01:58.070 --> 02:00.600 So that's zero one, two, three. 02:00.630 --> 02:01.140 Okay. 02:01.140 --> 02:08.190 And then four, five, six, seven and then eight to the end and you're going to cast that to an integer. 02:08.190 --> 02:10.020 And so you have red, green and blue. 02:10.140 --> 02:16.470 One very important thing is that when you send the command from the Raspberry Pi and also from Telegram, 02:16.470 --> 02:19.620 you have to respect the number of characters here. 02:19.650 --> 02:21.660 Okay, So I have shown you an example. 02:21.660 --> 02:24.300 So if you send 200 for red, you just put 200. 02:24.330 --> 02:30.510 If you want to put zero for green, you don't just put zero like this, you have to put three zero for 02:30.510 --> 02:31.560 it to work. 02:31.770 --> 02:34.200 And for 80 you just don't send 80. 02:34.230 --> 02:36.480 You send with a zero. 02:36.480 --> 02:39.900 So you make sure you have three characters for each color. 02:39.930 --> 02:40.470 Okay? 02:40.650 --> 02:44.040 And that's the way we are going to be able to read the colors. 02:44.070 --> 02:48.390 You could do something different, of course, to improve it, but we're going to stay with that. 02:48.390 --> 02:52.380 And that's a pretty efficient way actually to set the Led. 02:52.950 --> 02:55.860 Okay, so that's it for the Arduino side on the Raspberry Pi side. 02:55.860 --> 02:59.010 So you're going to connect to Serial, you're going to create some. 02:59.010 --> 03:02.940 So here you don't send notification to Telegram, you receive some comments. 03:02.940 --> 03:07.260 So you're going to create a command handler with an update data, a dispatcher. 03:07.260 --> 03:12.960 And then when you receive a command, you directly pass it to the Arduino, okay, with the correct 03:13.320 --> 03:13.890 command. 03:13.890 --> 03:27.090 So, for example, if I send here, let's say RGB and then so 200 comma, 000 comma zero 80, if I send 03:27.090 --> 03:33.630 this and exactly this, you're going to receive that on the Raspberry Pi and you're not going to send 03:33.660 --> 03:40.500 RGB, you're going to send set Led colon, you're going to add this and you're going to add a new line 03:40.500 --> 03:41.160 character. 03:41.160 --> 03:45.750 So you receive the command from Telegram on the Raspberry Pi and you make sure that you send the correct 03:45.750 --> 03:51.120 command for the Arduino so that the Arduino can understand what you're asking to do. 03:51.660 --> 03:52.080 Okay. 03:52.080 --> 03:55.200 I will see you in the next lesson for the solution.