PID Controlled DC Engine Test Rig

1//////////PID///////////
2#include <PID_v1.h>
3
4//////////Display///////////
5#include  <LiquidCrystal_I2C.h>
6
7//////////PID///////////
8//Define variable
9double  Setpoint = 0, Input = 0, Output = 0;
10//Define the PID named myPID
11PID myPID(&Input,  &Output, &Setpoint, 1, 1, 0, DIRECT);
12
13//////////Display///////////
14LiquidCrystal_I2C  lcd(0x27, 20, 4); // set the LCD address to 0x27 for a 16 chars and 2 line display
15unsigned  long t3 = 0;
16unsigned long update_time = 200;
17
18/////Sensor////
19int LDR_Pin  = A0;
20unsigned long t1, t2;
21unsigned long braketime = 300000;
22unsigned  long dt = 0;
23unsigned long rpm = 0;
24int wait_time = 2;
25
26
27/////Driver////
28//channels
29const  int pwm = 9;
30const int in_1 = 5;
31const int in_2 = 6;
32const int led_pin  = 13;
33
34//////Poti/////
35int Pot_pin = A2;
36
37void setup() {
38
39  lcd.init();                      // initialize the lcd
40  lcd.backlight();
41
42  myPID.SetMode(AUTOMATIC);       //turn the PID on
43
44  Serial.begin(9600);
45  
46  pinMode(pwm, OUTPUT);           //define channels
47  pinMode(in_1, OUTPUT);
48  pinMode(in_2, OUTPUT);
49  pinMode(led_pin, OUTPUT);
50
51  digitalWrite(led_pin,  HIGH);    //turn led on
52}
53
54void loop() {
55
56  //Define the Setpoint
57  //Setpoint = (sin(3.0 * millis() / (1000.0 * 2 * 3.14)) + 2.0 ) * 500.0;
58  //Setpoint  = 0;
59  Setpoint = analogRead(Pot_pin) * 5.0;
60
61  ////////measure and calculate  rpm////////
62  /////////////////////////////////////////
63  //detecting the  time dt which passes between two holes
64  
65  //1. starting at an unknown state  and wait until the photoresistor indicates that the light barrier is blocked
66  t2 = micros();                          //t2 indicates the starting time of the  loop
67  while (analogRead(LDR_Pin) < 850) {     //The loop runs until the LDR  signal is lower than the threshold of 850
68    if (micros() - t2 > braketime)  {      //If the loop runs longer than braketime e.g. the rotor did not move the  loop stopped
69      break;
70    }
71  }
72  delay(wait_time);                       //this  delay time is needed due to the noise in the signal
73  //2. wait until the next  hole appears and save this time to the variable t1
74  t2 = micros();                        
75  while (analogRead(LDR_Pin) > 850) {     //The loop runs until the LDR signal is  higher than the threshold of 850
76    if (micros() - t2 > braketime) {      
77      break;
78    }
79  }
80  t1 = micros();                          //save  the time when the first hole appear to t1
81  delay(wait_time);                       //this  delay time is needed due to the noise in the signal
82  //3. wait until the hole  disappears
83  t2 = micros();                        
84  while (analogRead(LDR_Pin)  < 850) {     //The loop runs until the LDR signal is lower than the trashhold of  850
85    if (micros() - t2 > braketime) {      
86      break;
87    }
88  }
89  delay(wait_time);                       //this delay time is needed due to the  noise in the signal
90
91  //4.wait until the next hole appears
92  t2 = micros();                          
93  while (analogRead(LDR_Pin) > 850) {     //The loop  runs until the LDR signal is higher than the trashhold of 850
94    if (micros()  - t2 > braketime) {
95      break;
96    }
97  }
98  dt = micros() - t1;                     //calculate  the time between the two holes
99  delay(wait_time);         
100  rpm = (1.0 /  (dt / 60000000.0)) / 2.0;  //calculate the rpm 
101
102  //use the PID controller  
103  Input = rpm;
104  myPID.Compute();
105  digitalWrite(in_1, HIGH);               //Defining  the turning direktion
106  digitalWrite(in_2, LOW);
107  analogWrite(pwm, Output);               //apply the Output to the DC motor
108
109  Serial.print(rpm - Setpoint);           
110  Serial.print(",");
111  Serial.print(rpm);
112  Serial.print(",");
113  Serial.print(Setpoint);
114  Serial.print(",");
115  Serial.println(Output);
116
117  //show results at the LCD
118  if (millis() - t3 > update_time)
119  {
120    t3  = millis();
121    lcd.clear();
122    lcd.setCursor(0, 0);
123    lcd.print("set  rpm");
124    lcd.setCursor(8, 0);
125    lcd.print(int(Setpoint));
126    lcd.setCursor(13,  0);
127    lcd.print("U/m");
128    lcd.setCursor(0, 1);
129    lcd.print("act  rpm");
130    lcd.setCursor(8, 1);
131    lcd.print(int(rpm));
132    lcd.setCursor(13,  1);
133    lcd.print("U/m");
134  }
135}

1//////////PID///////////
2#include <PID_v1.h>
3
4//////////Display///////////
5#include
6  <LiquidCrystal_I2C.h>
7
8//////////PID///////////
9//Define variable
10double
11  Setpoint = 0, Input = 0, Output = 0;
12//Define the PID named myPID
13PID myPID(&Input,
14  &Output, &Setpoint, 1, 1, 0, DIRECT);
15
16//////////Display///////////
17LiquidCrystal_I2C
18  lcd(0x27, 20, 4); // set the LCD address to 0x27 for a 16 chars and 2 line display
19unsigned
20  long t3 = 0;
21unsigned long update_time = 200;
22
23/////Sensor////
24int LDR_Pin
25  = A0;
26unsigned long t1, t2;
27unsigned long braketime = 300000;
28unsigned
29  long dt = 0;
30unsigned long rpm = 0;
31int wait_time = 2;
32
33
34/////Driver////
35//channels
36const
37  int pwm = 9;
38const int in_1 = 5;
39const int in_2 = 6;
40const int led_pin
41  = 13;
42
43//////Poti/////
44int Pot_pin = A2;
45
46void setup() {
47
48
49  lcd.init();                      // initialize the lcd
50  lcd.backlight();
51
52
53  myPID.SetMode(AUTOMATIC);       //turn the PID on
54
55  Serial.begin(9600);
56
57  
58  pinMode(pwm, OUTPUT);           //define channels
59  pinMode(in_1, OUTPUT);
60
61  pinMode(in_2, OUTPUT);
62  pinMode(led_pin, OUTPUT);
63
64  digitalWrite(led_pin,
65  HIGH);    //turn led on
66}
67
68void loop() {
69
70  //Define the Setpoint
71
72  //Setpoint = (sin(3.0 * millis() / (1000.0 * 2 * 3.14)) + 2.0 ) * 500.0;
73  //Setpoint
74  = 0;
75  Setpoint = analogRead(Pot_pin) * 5.0;
76
77  ////////measure and calculate
78  rpm////////
79  /////////////////////////////////////////
80  //detecting the
81  time dt which passes between two holes
82  
83  //1. starting at an unknown state
84  and wait until the photoresistor indicates that the light barrier is blocked
85
86  t2 = micros();                          //t2 indicates the starting time of the
87  loop
88  while (analogRead(LDR_Pin) < 850) {     //The loop runs until the LDR
89  signal is lower than the threshold of 850
90    if (micros() - t2 > braketime)
91  {      //If the loop runs longer than braketime e.g. the rotor did not move the
92  loop stopped
93      break;
94    }
95  }
96  delay(wait_time);                       //this
97  delay time is needed due to the noise in the signal
98  //2. wait until the next
99  hole appears and save this time to the variable t1
100  t2 = micros();                        
101
102  while (analogRead(LDR_Pin) > 850) {     //The loop runs until the LDR signal is
103  higher than the threshold of 850
104    if (micros() - t2 > braketime) {      
105
106      break;
107    }
108  }
109  t1 = micros();                          //save
110  the time when the first hole appear to t1
111  delay(wait_time);                       //this
112  delay time is needed due to the noise in the signal
113  //3. wait until the hole
114  disappears
115  t2 = micros();                        
116  while (analogRead(LDR_Pin)
117  < 850) {     //The loop runs until the LDR signal is lower than the trashhold of
118  850
119    if (micros() - t2 > braketime) {      
120      break;
121    }
122  }
123
124  delay(wait_time);                       //this delay time is needed due to the
125  noise in the signal
126
127  //4.wait until the next hole appears
128  t2 = micros();
129                          
130  while (analogRead(LDR_Pin) > 850) {     //The loop
131  runs until the LDR signal is higher than the trashhold of 850
132    if (micros()
133  - t2 > braketime) {
134      break;
135    }
136  }
137  dt = micros() - t1;                     //calculate
138  the time between the two holes
139  delay(wait_time);         
140  rpm = (1.0 /
141  (dt / 60000000.0)) / 2.0;  //calculate the rpm 
142
143  //use the PID controller
144  
145  Input = rpm;
146  myPID.Compute();
147  digitalWrite(in_1, HIGH);               //Defining
148  the turning direktion
149  digitalWrite(in_2, LOW);
150  analogWrite(pwm, Output);
151               //apply the Output to the DC motor
152
153  Serial.print(rpm - Setpoint);
154           
155  Serial.print(",");
156  Serial.print(rpm);
157  Serial.print(",");
158
159  Serial.print(Setpoint);
160  Serial.print(",");
161  Serial.println(Output);
162
163
164  //show results at the LCD
165  if (millis() - t3 > update_time)
166  {
167    t3
168  = millis();
169    lcd.clear();
170    lcd.setCursor(0, 0);
171    lcd.print("set
172  rpm");
173    lcd.setCursor(8, 0);
174    lcd.print(int(Setpoint));
175    lcd.setCursor(13,
176  0);
177    lcd.print("U/m");
178    lcd.setCursor(0, 1);
179    lcd.print("act
180  rpm");
181    lcd.setCursor(8, 1);
182    lcd.print(int(rpm));
183    lcd.setCursor(13,
184  1);
185    lcd.print("U/m");
186  }
187}