WEBVTT 00:00.110 --> 00:04.220 Before we start using the Pir sensor, we actually need to tune it. 00:04.220 --> 00:09.590 So there are a few things here we will need to do on the hardware, and it's quite important that we 00:09.590 --> 00:15.470 do it actually even before we do the circuit, because if we're going to touch stuff directly on the 00:15.470 --> 00:22.370 hardware and actually metallic parts, well, as you guess, it's better to have the sensor outside 00:22.370 --> 00:26.510 of the circuit and especially not in the circuit and powered on. 00:26.510 --> 00:32.180 So as you can see on the Pir sensor we have here, we have first this is called a jumper. 00:32.180 --> 00:36.830 So this yellow thingy here with three wires here. 00:36.830 --> 00:38.750 So it might be in either position. 00:38.750 --> 00:40.520 You can just take it out for now. 00:40.610 --> 00:45.410 So we have this jumper and then we have two potentiometers here okay. 00:45.440 --> 00:51.800 So I'm going to explain to you what to do with those three things here and what that means. 00:51.800 --> 00:53.810 So first of all you can take the jumper. 00:53.810 --> 00:56.720 And if you look carefully here at the back. 00:56.720 --> 01:04.930 So if I orientate the Pir sensor so like this you can see that we have L and H so low or high. 01:04.960 --> 01:08.980 Basically what you can also just take it like that and it's going to be on the left. 01:08.980 --> 01:17.320 So take the jumper and you connect the two pins on to the two legs on the left on the high position. 01:17.320 --> 01:19.600 And I'm going to come back to this in just a minute. 01:19.600 --> 01:22.660 Then you can orientate the Pi like that. 01:22.660 --> 01:24.190 So it depends on how you orient it. 01:24.190 --> 01:29.830 I'm going to follow the instructions with the sensor that's on the bottom here. 01:29.830 --> 01:31.660 And you have two potentiometers. 01:31.660 --> 01:34.900 So to move those you see I have some screwdrivers. 01:34.900 --> 01:42.310 So you can find any screwdriver and try to see if you can actually turn the potentiometer okay. 01:42.310 --> 01:43.570 So with this one it works. 01:43.570 --> 01:45.520 I also have a flat one. 01:45.850 --> 01:50.440 Well you can also try with your finger okay I don't have much nail here. 01:50.440 --> 01:50.920 You can see. 01:50.920 --> 01:55.840 But I can still manage to turn the potentiometer here. 01:55.840 --> 02:02.150 So you will find a way to turn this, and the first potentiometer on the left here will correspond to 02:02.180 --> 02:03.350 the range. 02:03.350 --> 02:06.650 So how far the sensor can detect movement? 02:07.010 --> 02:09.170 The minimum is going to be three meters. 02:09.200 --> 02:09.440 Okay. 02:09.470 --> 02:15.590 So it can detect up to one up to three meters in front with a with a with a range. 02:15.590 --> 02:18.140 Imagine here you have an angle here. 02:18.140 --> 02:20.510 That's I think it's about 110 degrees. 02:20.510 --> 02:23.150 And it's going to detect movement up to three meters. 02:23.150 --> 02:24.260 That's the minimum. 02:24.260 --> 02:33.260 So if you will go counterclockwise at the minimum like like that. 02:35.060 --> 02:36.050 Let's see okay. 02:36.080 --> 02:42.170 All the way here that's going to be three meters if you go all the way up here. 02:43.040 --> 02:46.250 So clockwise is going to be seven meters okay. 02:46.250 --> 02:52.490 So from 3 to 7m and it's well I'm just going to put it in the middle. 02:52.490 --> 02:55.800 So it's going to be somewhere around five metres. 02:55.800 --> 02:58.140 This one is not the most important setting. 02:58.170 --> 02:58.380 Okay. 02:58.410 --> 03:03.870 And it's going to basically depend on where you place the sensor and what you want to detect. 03:03.900 --> 03:07.050 So for this example we don't need any precise range. 03:07.050 --> 03:10.110 You could leave it to three meters or five whatever. 03:10.110 --> 03:11.610 And then the second one. 03:11.610 --> 03:16.680 So with the sensor on the bottom here the potentiometer on the right. 03:16.680 --> 03:23.970 This one is more important because this one is the delay or basically how long the output of the sensor 03:23.970 --> 03:25.920 will stay high. 03:26.370 --> 03:27.990 Because how does the sensor work? 03:27.990 --> 03:32.400 Well, when the movement is detected it's going to output high okay. 03:32.430 --> 03:33.870 By default it's going to be low. 03:33.870 --> 03:36.660 When the movement is detected it's going to output high. 03:36.660 --> 03:38.520 And you can read that in your code. 03:38.520 --> 03:45.690 But what you have to know is that when the sensor output high, it will stay high for a certain amount 03:45.720 --> 03:46.530 of time. 03:46.560 --> 03:46.830 Okay. 03:46.860 --> 03:51.000 And this amount of time you can modify it with this potentiometer. 03:51.000 --> 03:52.440 If I go on the minimum. 03:52.440 --> 03:54.740 And actually we're going to go to the minimum here. 03:55.820 --> 03:58.070 So I put this potentiometer to the minimum. 03:58.070 --> 04:04.580 This is going to be about so well depends on which datasheet you find on the internet. 04:04.850 --> 04:07.730 Because it seems like nobody can agree on this. 04:07.730 --> 04:11.180 But what I found is values between 3 to 5 seconds. 04:11.180 --> 04:16.370 And with this potentiometer here, this hardware that I have, I found it's about three seconds. 04:16.370 --> 04:17.870 So that's going to be the minimum. 04:17.870 --> 04:23.360 Which means that when the movement is detected it's going to be like if it were detected for the next 04:23.360 --> 04:26.030 three seconds, even if there is no movement. 04:26.030 --> 04:28.790 So I put my hand here. 04:28.790 --> 04:31.340 It's going to detect the movement and stay high. 04:31.370 --> 04:34.610 So stay as detected for three seconds. 04:34.640 --> 04:39.980 If you put all the way to the top so clockwise it will go up until 300 seconds. 04:39.980 --> 04:41.660 So five minutes. 04:41.690 --> 04:42.170 All right. 04:42.200 --> 04:45.440 So for this application we want the minimum we want to have the minimum. 04:45.440 --> 04:47.540 So 3 to 5 seconds okay. 04:47.570 --> 04:50.270 So we have the first potentiometer here. 04:50.270 --> 04:53.870 Whatever value it's the range between 3 to 7m. 04:53.900 --> 05:00.290 This potentiometer here, the minimum counterclockwise which is going to be about five. 05:00.290 --> 05:01.670 So 3 to 5 seconds. 05:01.670 --> 05:05.270 And then I'm coming back to this jumper here. 05:05.300 --> 05:07.640 And I told you to put it in a high position. 05:07.670 --> 05:13.250 Because if you put it in the low position and for example here it's going to detect the movement for 05:13.250 --> 05:13.970 three seconds. 05:13.970 --> 05:17.090 Then after three seconds it's going to go low again. 05:17.090 --> 05:22.280 So it's going to say that there is no movement detected even if you continue to move, for example, 05:22.280 --> 05:24.620 your hand in front of the sensor. 05:24.650 --> 05:25.160 All right. 05:25.190 --> 05:31.940 With the high position, basically every time you make a movement, you kind of reset this delay. 05:31.940 --> 05:37.400 So as long as you make movement in front of the sensor, the output is always going to be high. 05:37.400 --> 05:42.350 Plus an additional, let's say 3 to 5 seconds after the last movement. 05:42.380 --> 05:42.830 Okay. 05:42.830 --> 05:48.590 So that's the settings that we're going to use for this circuit and for the activities and also for 05:48.590 --> 05:50.270 the project of this course.