1 00:00:00,870 --> 00:00:04,710 What is a vending machine controller and how can we design that? 2 00:00:04,740 --> 00:00:07,700 Nicholas, this lecture will cope with this question. 3 00:00:12,000 --> 00:00:19,260 Several electronic automated systems, such as vending machine dishwashers and robots, to name a few, 4 00:00:19,380 --> 00:00:27,720 are working by going through several tasks or states based on the input, data or settings adjusted 5 00:00:27,720 --> 00:00:28,460 by users. 6 00:00:29,280 --> 00:00:34,650 They usually utilize digital controllers to guide the machine throughout their state's. 7 00:00:36,240 --> 00:00:40,220 It the state machine is a common way to model these controllers. 8 00:00:40,740 --> 00:00:48,060 The control process of all these examples consists of a few states and the controller can only go from 9 00:00:48,060 --> 00:00:54,930 one state to another if it receives the correct inputs and only a set of acceptable state transitions 10 00:00:54,930 --> 00:00:55,650 are possible. 11 00:00:58,390 --> 00:01:06,760 Here we take a simplified controller for a vending machine as an example to describe that this machine 12 00:01:06,760 --> 00:01:09,580 sells candy bars for twenty five cents. 13 00:01:10,900 --> 00:01:19,810 The inputs are nickel and diming and cautery, indicating the type of coin that was deposited, the 14 00:01:19,810 --> 00:01:26,020 circuit controller responses with the outputs, can they underscore out to dispense a candy bar, plus 15 00:01:26,200 --> 00:01:32,140 nickel underscore out or dayme underscore out, asserted when change is due? 16 00:01:34,020 --> 00:01:41,580 The controller has another input named thanks, underscoring this input is asserted when you take your 17 00:01:41,580 --> 00:01:46,710 candy and check, it resets the system ready for the next candy request. 18 00:01:50,590 --> 00:01:52,370 Let's throw the finite state machine. 19 00:01:53,350 --> 00:02:00,210 The controller starts at the state e0 zero, if you put a nickel coin, it goes to the eighty five state. 20 00:02:00,820 --> 00:02:04,630 If you put a dime coin, it goes to the Stenness state. 21 00:02:05,050 --> 00:02:09,080 And if you put a quarter coin, it goes to the state 25 state. 22 00:02:10,150 --> 00:02:13,180 Now let's assume the controller is in city five. 23 00:02:13,930 --> 00:02:16,840 If you put a nickel coin, it goes to Stan. 24 00:02:17,680 --> 00:02:25,090 If you put a dime coin, it goes to S.T. 15, and if we put a quarter coin, it goes to ESTIE 30. 25 00:02:26,680 --> 00:02:29,470 Now, let's assume the controller is in city 10. 26 00:02:30,310 --> 00:02:33,100 If you put a nickel coin, it goes to city 15. 27 00:02:33,820 --> 00:02:41,440 If we put a dime coin, it goes to ESTIE 20, and if we put a quarter coin, it goes to ESTIE 35. 28 00:02:43,270 --> 00:02:50,890 Now, let's assume the controller is in city 15, if you put a nickel coin, it goes to ESTIE 20, if 29 00:02:50,890 --> 00:02:57,310 you put a dime coin, it goes to S.T. 25, and if you put a quarter coin, it goes to E40. 30 00:02:58,210 --> 00:03:00,760 Now, let's assume the controller is in a state 20. 31 00:03:01,360 --> 00:03:04,110 If you put a nickel coin, it goes to a city 25. 32 00:03:04,750 --> 00:03:07,380 If you put a dime coin, it goes to city 30. 33 00:03:07,990 --> 00:03:11,680 And if you put a quarter coin, it goes to ESTIE 45. 34 00:03:15,050 --> 00:03:21,950 Now, let's assume the controller is in a state 25, then the machine gives you a candy and the controller 35 00:03:22,100 --> 00:03:26,000 goes to state a suite waiting for you to take the candy. 36 00:03:26,960 --> 00:03:33,260 Now, if the controller is not 30, then the machine gives you a candy and then they kill and the controller 37 00:03:33,260 --> 00:03:36,560 goes to state as wait, waiting for you to take the candy. 38 00:03:37,250 --> 00:03:44,090 Now, if the controller is in C 35, then the machine gives you a candy and a dime and the controller 39 00:03:44,240 --> 00:03:47,570 goes to a state suite waiting for you to take the candy. 40 00:03:48,600 --> 00:03:55,050 Now, if the controller is in difficulty, then the machine gives you a candy, a nickel and a dime 41 00:03:55,470 --> 00:04:00,000 and the controller goes to state a suerte waiting for you to take the country. 42 00:04:00,450 --> 00:04:07,260 Now, if the controller is in city 45, then the machine gives you a candy and two dimes and the controller 43 00:04:07,380 --> 00:04:11,340 goes to a state, a suite waiting for you to take the candy. 44 00:04:11,350 --> 00:04:18,110 If the controller is in a sweet and you take the candy and you change, the system goes to a state zero 45 00:04:18,270 --> 00:04:19,770 ready for the next purchase. 46 00:04:22,210 --> 00:04:28,120 In addition, the controller uses the system reset to reset the vending machine whenever it is a cost. 47 00:04:31,190 --> 00:04:37,430 How can we describe this, a state machine in the next lecture will implement this FSM, invite the 48 00:04:37,440 --> 00:04:38,020 socialist. 49 00:04:43,520 --> 00:04:45,080 These are our takeaway messages. 50 00:04:46,300 --> 00:04:52,590 The behavior of the most electronic automated system can be described by finite state machines, since 51 00:04:53,320 --> 00:04:59,500 drawing an accurate FSM with all the input and output details is the first step to design a digital 52 00:04:59,500 --> 00:05:01,330 controller for such systems. 53 00:05:04,900 --> 00:05:09,890 Now, the quiz question in our efforts and diagram, which states accept includes.