WEBVTT 00:00.210 --> 00:05.610 In this new activity, you are going to do something a little bit different with your photoresistor 00:05.610 --> 00:08.680 senseor and let's say a little bit more scientific. 00:09.060 --> 00:15.980 So when you have a sensor that gives you some values or photoresistor temperature sensor or put on Schmitter, 00:16.050 --> 00:23.910 a ultrasonic distance sensor, whatever, so it can be interesting to know not only what values you 00:23.910 --> 00:29.580 get from the sensor, but what is the average value you get over a certain period of time. 00:30.390 --> 00:36.360 So, for example, for the photoresistor sensor, you might put it somewhere and compute the average 00:36.420 --> 00:39.040 luminosity you get over 24 hours. 00:39.110 --> 00:43.890 OK, for example, of a one hour of whatever period of time you want. 00:44.100 --> 00:50.760 So to do that, what you need to do is to read some data from the sensor every X amount of time that 00:50.760 --> 00:55.180 you define and each reading, we are going to call that a sample. 00:55.200 --> 01:01.110 So you are going to save those samples inside an array and after a certain period of time, you are 01:01.110 --> 01:03.530 going to compute the average of these three. 01:03.900 --> 01:09.700 So this doing this can be very useful to do some measurements of your environment. 01:10.320 --> 01:15.690 So what you are going to do in this activity, you are going to get some simple so gets simpler. 01:15.690 --> 01:17.460 So it gets luminosity simple. 01:19.240 --> 01:23.160 Simple every 50 milliseconds. 01:23.800 --> 01:27.140 OK, four, five, six. 01:27.670 --> 01:30.550 So actually, that's one hundred samples. 01:31.180 --> 01:36.850 Of course, I'm not going to make the example for twenty four hours because the twenty four hour video 01:36.880 --> 01:38.380 will be quite boring. 01:38.590 --> 01:42.730 But let's use this for one hundred samples that we take every 15 minutes. 01:43.210 --> 01:48.210 OK, and then those two parameters, you can just modify them as you want. 01:48.400 --> 01:53.970 And then so when you have those one hundred samples you are going to compute the average. 01:54.370 --> 01:57.610 So to compute the average, if you don't know the formula. 01:57.620 --> 01:58.920 The formula is very simple. 01:58.930 --> 02:05.410 You take the sum of all values and you divide that by the number of values. 02:05.590 --> 02:11.900 So for one hundred samples, you make the sum of all the elements in the array and you divide it by 02:12.040 --> 02:12.660 one hundred. 02:13.150 --> 02:15.680 And so what you're going to do is you're going to print. 02:15.700 --> 02:22.930 So you're going to measure that, OK, in 15 milliseconds using the time functionality, of course, 02:22.930 --> 02:23.730 and not delay. 02:23.950 --> 02:32.200 And then after you get one hundred samples, you compute the average and you print print the average. 02:35.560 --> 02:41.500 So here you are going to need to use arrays, function and the average computation here. 02:41.770 --> 02:42.190 All right. 02:42.200 --> 02:45.400 And I will see you in the next lesson folder solution.