1 00:00:00,910 --> 00:00:02,100 Hello, welcome back. 2 00:00:02,740 --> 00:00:09,700 And this lesson, we go in to see how to work with the gatekeeper task, I'm going to create a new project 3 00:00:09,700 --> 00:00:12,040 by making a copy of the last one over here. 4 00:00:12,400 --> 00:00:14,770 I'll copy and paste it over here. 5 00:00:15,190 --> 00:00:17,380 I'll call this gatekeeper. 6 00:00:22,710 --> 00:00:23,340 Like this. 7 00:00:23,850 --> 00:00:24,350 OK. 8 00:00:28,220 --> 00:00:29,240 So it's cop in. 9 00:00:32,710 --> 00:00:38,350 OK, so I'm going to open our gate keeper to ask. 10 00:00:40,000 --> 00:00:41,200 This is minimized. 11 00:00:43,190 --> 00:00:52,430 Here we are, gatekeeper over here, source and may not see over here, so we go in to achieve what 12 00:00:52,430 --> 00:00:54,490 we've been achieving with our semaphores. 13 00:00:54,500 --> 00:00:59,600 But this time without semaphores, we're going to use our gatekeeper and the gatekeeper is going to 14 00:00:59,600 --> 00:01:04,970 be the task which is keeping the gate for our serial port. 15 00:01:04,970 --> 00:01:08,660 Our Ewart's is going to be handled by just one task. 16 00:01:08,930 --> 00:01:16,700 So both our analog sensor task and our digital sensor task, if they have something to print, they 17 00:01:16,700 --> 00:01:21,180 have to give it to the gatekeeper task to print it for them. 18 00:01:21,830 --> 00:01:23,930 That is what we going to do over here. 19 00:01:24,140 --> 00:01:29,270 So over here, we don't require semaphores or delete our semaphore handle here and then. 20 00:01:31,070 --> 00:01:36,320 So currently, I've just deleted our SEMAFO, Honda or Semaphore crates of deleted as well. 21 00:01:36,690 --> 00:01:37,160 OK. 22 00:01:39,030 --> 00:01:46,320 So what do we have we have two tasks, we have our Botin Reid task and we have a white button, Reid 23 00:01:46,320 --> 00:01:52,320 and Senator Reid, and we know Button Reid is our digital button and then sensor is, of course, our 24 00:01:52,320 --> 00:01:52,910 ADC. 25 00:01:53,190 --> 00:01:59,880 What I'm going to do next is I'm going to clean this bit here where we were taken and given to SEMAFO. 26 00:01:59,880 --> 00:02:03,600 I'm going to clean it in both of these task functions. 27 00:02:04,110 --> 00:02:11,910 Such that's what we have left in our digital sense or task is just read the digital sense or storage 28 00:02:11,910 --> 00:02:18,600 in a variable, and then we toss one here and what we have in our analog senso with the analog sense 29 00:02:18,600 --> 00:02:19,920 or storage in a variable. 30 00:02:19,920 --> 00:02:21,980 And we have to delay one here. 31 00:02:22,530 --> 00:02:26,880 So we're going to create a third task known as the gatekeeper task. 32 00:02:27,450 --> 00:02:37,140 And this would have the same it would have the same amount of rum, the same success story as the other 33 00:02:37,140 --> 00:02:37,650 tasks. 34 00:02:38,670 --> 00:02:40,850 We're going to give this a priority of zero. 35 00:02:40,890 --> 00:02:42,590 The others have a priority of one. 36 00:02:42,600 --> 00:02:46,710 So our gatekeeper essentially has the lowest priority here. 37 00:02:47,040 --> 00:02:48,090 No problem with this. 38 00:02:48,870 --> 00:02:49,300 Right. 39 00:02:49,530 --> 00:02:55,860 So now the question is, how are we going to get information from our tasks to the gatekeeper? 40 00:02:56,460 --> 00:03:03,390 What are we going to do is employ a Q We're going to use a Q So if if a task has something to print, 41 00:03:03,600 --> 00:03:04,590 it would put it into. 42 00:03:04,590 --> 00:03:06,660 Q You can think of. 43 00:03:08,020 --> 00:03:15,610 You can think of being in an office with a number of computers and having a central computer that is 44 00:03:15,610 --> 00:03:20,800 connected to the printer such that if you want something to print, you send it to the central computer 45 00:03:21,220 --> 00:03:23,380 in the central computer keywords for you. 46 00:03:24,720 --> 00:03:29,340 In the printer, and then you print one after the other based on which arrived first. 47 00:03:29,940 --> 00:03:34,730 OK, so we have three tasks. 48 00:03:34,750 --> 00:03:36,510 Yeah, our bottom reader task. 49 00:03:36,510 --> 00:03:37,560 Sensory task. 50 00:03:37,560 --> 00:03:38,790 Our gatekeeper task. 51 00:03:39,330 --> 00:03:44,220 OK, next, we going to define the handle for a Q. 52 00:03:45,110 --> 00:03:52,850 Of course, we said we're going to use a cue, so I'll come up here and have this Q&A Hondo here, experiencer 53 00:03:52,850 --> 00:03:53,180 cue. 54 00:03:53,750 --> 00:03:58,610 OK, so since we have the handle for the cue, we have to create the cue, then we're going to see the 55 00:03:58,610 --> 00:03:59,150 cue. 56 00:03:59,630 --> 00:04:02,110 Should have a maximum capacity of two elements. 57 00:04:02,630 --> 00:04:07,770 So we see X execute great size of end. 58 00:04:07,790 --> 00:04:09,950 This is going to be the data type. 59 00:04:11,020 --> 00:04:17,150 And we want to study Hunda here, OK, once that is done, we said the name of our. 60 00:04:19,530 --> 00:04:25,200 Our gatekeeper task is task, we can call it a little task for now, right? 61 00:04:25,220 --> 00:04:30,570 You can call it zero printer task if you want, or LCD task. 62 00:04:30,580 --> 00:04:33,710 I'm just calling the LCD task here, OK? 63 00:04:33,870 --> 00:04:36,610 So that's the name we give the task function. 64 00:04:36,810 --> 00:04:37,880 We know this already. 65 00:04:38,220 --> 00:04:42,300 So I'm going to create an LCD task function down here. 66 00:04:42,310 --> 00:04:50,790 We have our first task function is the second one for the second task, the third one over here like 67 00:04:50,790 --> 00:04:51,150 this. 68 00:04:52,600 --> 00:04:55,100 We're going to have our infinite loop here. 69 00:04:57,900 --> 00:05:06,590 OK, so over here, in a digital sense or task, whenever it's reached the sense data we wanted to send 70 00:05:06,590 --> 00:05:12,050 DICENZO who wanted to send the button data to our queue. 71 00:05:12,870 --> 00:05:20,490 So what we want to do is see X, Q send it back because we want to add this to the Q. 72 00:05:21,880 --> 00:05:28,700 Excuse and to back and what we want to send is the button states, so what we read here, we send in 73 00:05:28,720 --> 00:05:33,040 it to the cute, OK, and we want to do the same for our. 74 00:05:34,040 --> 00:05:35,060 Analog Senseor. 75 00:05:36,310 --> 00:05:44,080 So the analog sensor volume that we store in this variable, we want to send that to the queue over 76 00:05:44,080 --> 00:05:45,670 here like this. 77 00:05:45,760 --> 00:05:50,080 OK, so then our queue has our sense of values. 78 00:05:50,860 --> 00:06:00,210 Now, what we want to do is go to our gatekeeper task over here and tell the gatekeeper task to wait. 79 00:06:01,360 --> 00:06:07,810 We're going to create a variable for the gatekeeper task to store what it received or of this variable 80 00:06:07,810 --> 00:06:10,540 into variable here called value to print. 81 00:06:11,200 --> 00:06:13,980 So the gatekeeper task is going to wait. 82 00:06:13,990 --> 00:06:17,960 We're going to see Portsmouth's delay over here. 83 00:06:17,960 --> 00:06:19,270 We're going to pass this over here. 84 00:06:19,300 --> 00:06:20,740 So we're going to wait. 85 00:06:22,270 --> 00:06:27,700 For data to become available, maximum delay, OK, so when the data is received from this key is going 86 00:06:27,700 --> 00:06:33,780 to be stored in this variable here and we can print the content of this variable without of. 87 00:06:34,660 --> 00:06:42,930 So you simply say printf here, and if we want to make it more complex, of course we can identify whether 88 00:06:42,940 --> 00:06:52,630 this is coming from the from the digital sense or the analog sense or using the the one of our Q examples 89 00:06:52,630 --> 00:06:57,580 where we had a structure, we would send in a structure to the Q and one of the structure members told 90 00:06:57,580 --> 00:07:04,540 us the the identification of the data, whether it was humidity data or pressure sense or data, we 91 00:07:04,540 --> 00:07:08,140 can use that method here to identify what arrives here. 92 00:07:08,290 --> 00:07:09,340 But this is simplified. 93 00:07:09,340 --> 00:07:11,070 We simply say new value. 94 00:07:11,800 --> 00:07:14,520 OK, let's build it and see what we've got. 95 00:07:14,620 --> 00:07:15,970 Now click over here to build. 96 00:07:18,260 --> 00:07:21,770 OK, we've not placed the prototype of this. 97 00:07:22,940 --> 00:07:26,500 Tosk function at a topia, so I'll place that over here. 98 00:07:27,870 --> 00:07:28,810 We're looking good. 99 00:07:28,830 --> 00:07:30,030 Click over here to build. 100 00:07:32,660 --> 00:07:33,860 It's built successfully. 101 00:07:34,820 --> 00:07:43,070 OK, I'm going to right click over here and also run us a STEM 32 double click on Gatekeeper. 102 00:07:44,400 --> 00:07:46,530 And I'll say, OK, over here. 103 00:07:55,290 --> 00:07:55,950 OK. 104 00:07:57,370 --> 00:07:58,090 Says. 105 00:07:58,980 --> 00:08:00,840 Download verified successfully. 106 00:08:01,820 --> 00:08:05,780 So I'm going to open this and I can see we have new value. 107 00:08:06,820 --> 00:08:09,260 OK, but that is rather strange. 108 00:08:09,790 --> 00:08:11,530 We simply have in our. 109 00:08:12,460 --> 00:08:18,550 Sense of value only, we're not receiving anything we have in just our digital sense of value. 110 00:08:18,580 --> 00:08:19,450 I'm pressing the button. 111 00:08:19,460 --> 00:08:20,470 That is why he's changing. 112 00:08:20,970 --> 00:08:24,280 We're not receiving the atkeson. 113 00:08:24,280 --> 00:08:27,400 So let's see where we could have gone wrong. 114 00:08:28,180 --> 00:08:29,320 We have this here. 115 00:08:32,290 --> 00:08:33,130 This is it's. 116 00:08:35,250 --> 00:08:36,510 We are in this. 117 00:08:37,610 --> 00:08:39,290 And it looks so to cue. 118 00:08:42,990 --> 00:08:43,650 AK. 119 00:08:47,410 --> 00:08:53,290 OK, we could solve this by making it more stable, we can just increase v task delay here from one 120 00:08:53,290 --> 00:08:56,620 to ten and then ten, OK? 121 00:08:57,730 --> 00:08:59,290 So click over here to build. 122 00:09:01,770 --> 00:09:04,720 It's built successfully, I'll click here to run. 123 00:09:16,630 --> 00:09:22,090 It's running, says the sea, as you can see now, we have our unlock value. 124 00:09:23,460 --> 00:09:27,090 And then or pushbutton, when I push, you can see it's change. 125 00:09:27,470 --> 00:09:33,690 OK, so this all the wrist, this all the wrist with regards to the gatekeeper to ask any questions, 126 00:09:33,690 --> 00:09:37,240 leave them in the questions and answers area and I'll see you later. 127 00:09:37,260 --> 00:09:38,150 Have a nice day.