WEBVTT 00:00.110 --> 00:02.890 This is the first activity of this course. 00:02.900 --> 00:08.750 What I'm going to do now is to give you a challenge and explain some steps or give you some tips to 00:08.750 --> 00:10.040 solve the challenge. 00:10.040 --> 00:13.340 In the next video, you will find the solution. 00:13.340 --> 00:19.520 Of course, I really encourage you to try to do the activity by yourself before you go to the solution. 00:19.520 --> 00:22.820 That's the only way to make progress. 00:22.820 --> 00:27.860 And if you have some doubts, feel free to rewatch some of the previous lessons. 00:28.100 --> 00:28.520 All right. 00:28.520 --> 00:36.440 So your challenge for this activity is to power on or power off an on the Arduino from the Raspberry 00:36.440 --> 00:36.770 Pi. 00:37.220 --> 00:44.030 So on the Arduino, we actually well, we haven't created a circuit yet, but we have the built in Led. 00:44.030 --> 00:50.980 So you have the built in Led, which is on PIN 13. 00:51.890 --> 00:52.050 Okay. 00:52.100 --> 00:59.810 So you can first create, for example, a define for that and then use pin mode with 13 and output and 00:59.910 --> 01:08.550 then what you are going to do in the void loop is basically to read string from Serial. 01:08.550 --> 01:14.610 So you're going to check if you have some data with Serial available, you're going to read the string. 01:14.610 --> 01:21.900 And then depending on the value of that string, you are going to power on or power off the Led. 01:21.930 --> 01:28.590 So of course you will need to agree on a common value you receive here and the value you send here. 01:28.620 --> 01:28.830 Okay. 01:28.830 --> 01:31.830 You need to send the same value that you're going to receive here. 01:31.830 --> 01:36.150 So for example, that can be on and that can be off. 01:36.150 --> 01:43.230 So when you receive on from you power on the Led, when you receive off from serial, you power off 01:43.230 --> 01:43.860 the Led. 01:44.190 --> 01:44.760 All right. 01:44.760 --> 01:47.190 So that would be the code on the Arduino. 01:47.580 --> 01:49.230 Now on the Raspberry Pi. 01:49.260 --> 01:54.210 So first you are going to init communication. 01:54.600 --> 01:55.770 So you have two choices. 01:55.770 --> 01:56.640 Do we need the communication? 01:56.640 --> 02:02.340 You can just open the serial and see what's happening, if it works or not, or you can also use the 02:02.340 --> 02:06.270 try again mechanism that you have just coded in the previous section. 02:06.270 --> 02:12.750 And then well, what you are going to do is you are going to send so you're going to send on. 02:13.920 --> 02:17.070 Or off and how you are going to send that? 02:17.070 --> 02:23.910 Well, what you could do is, for example, send on every second and then send off and then send on 02:23.910 --> 02:24.210 again. 02:24.210 --> 02:25.380 Send off every second. 02:25.410 --> 02:25.800 All right. 02:25.800 --> 02:31.170 But what we are going to do here is we are going to use the input function. 02:31.170 --> 02:31.380 Okay. 02:31.380 --> 02:36.600 So the input function in Python as a reminder, will ask for the user. 02:36.600 --> 02:40.320 So in the terminal we ask for the user to give some data. 02:40.320 --> 02:45.060 So for example, the string and then you can get the string into your code. 02:45.150 --> 02:45.410 Okay? 02:45.420 --> 02:54.780 So you can put for example, input with select on or off like this with maybe some quotes. 02:55.540 --> 02:58.060 So you can ask the user to select on or off. 02:58.060 --> 03:03.220 And then you read that and if the user gives on you, send on to the Arduino. 03:03.250 --> 03:07.180 If the user gives off, you send off to the Arduino. 03:07.330 --> 03:07.920 Okay. 03:07.930 --> 03:11.890 So what you can do is put that input function inside a while. 03:11.920 --> 03:12.540 True loop. 03:12.550 --> 03:12.740 Okay. 03:12.790 --> 03:16.270 To make kind of a void loop like we have on the Arduino. 03:16.270 --> 03:23.080 So you first initialize communication and then you create a while loop to continuously get the user 03:23.080 --> 03:23.440 input. 03:23.440 --> 03:27.670 And whenever you get the user input, you send that input to the Arduino. 03:28.150 --> 03:28.570 All right. 03:28.570 --> 03:35.680 So here what we are going to be able to do is to get user input on the Raspberry Pi to power on a hardware 03:35.680 --> 03:37.510 component on the Arduino. 03:37.510 --> 03:38.170 All right. 03:38.320 --> 03:43.510 And now once again, make sure to work on that challenge before you watch the solution. 03:43.510 --> 03:43.900 Okay. 03:43.900 --> 03:46.770 So spend some time working on this. 03:46.780 --> 03:50.860 However, don't stay stuck for hours and hours, okay? 03:50.860 --> 03:56.120 If you can't make it work, no worries at all because, well, for this course, the activities have 03:56.120 --> 03:58.580 picked can be quite challenging. 03:58.580 --> 04:04.100 So in this case, if you can't make it work, just watch the solution and then try to do the activity 04:04.130 --> 04:06.950 again on your own a bit later.