Automotive Engine Rev-Limiter

1// Rev-Limiter Code for Arduino Project Hub
2//
3//Written by Adrianos  Botis: adrianosbotis@gmail.com
4//
5//Use at your own and change the parameters:  rpm_val to set the rpm limit of your engine.
6//You can also change the delay  of milliseconds at the end of the code to set how fast your engine will be switched  on-off.
7//
8
9
10int sensor_pin = 3;
11// set number of hall trips for  RPM reading (higher improves accuracy)
12float sensor_thresh = 5.0;
13int ignition  = 2;
14
15void setup() {
16  // initialize serial communication at 9600 bits  per second:
17  Serial.begin(9600);
18  // make the sensor pin an input:
19  pinMode(sensor_pin,  INPUT);
20  pinMode(ignition, OUTPUT);
21}
22
23// this loop routine runs over  and over again forever:
24void loop() {
25  // preallocate values for tach
26  float hall_count = 1.0;
27  float start = micros();
28  bool on_state = false;
29  // counting number of times the hall sensor is tripped
30  // but without double  counting during the same trip
31  while(true){
32    if (digitalRead(sensor_pin)  == 1){
33      if (on_state==false){
34        on_state = true;
35        hall_count+=1.0;
36      }
37    } else{
38      on_state = false;
39    }
40    
41    if (hall_count>=sensor_thresh){
42      break;
43    }
44  }
45  
46  // print information about Time and RPM
47  float end_time = micros();
48  float time_passed = ((end_time-start)/1000000.0);
49  Serial.print("Time Passed: ");
50  Serial.print(time_passed);
51  Serial.println("s");
52  float rpm_val = (sensor_thresh/(2*time_passed))*60.0;
53   if(rpm_val > 8000.0){
54     digitalWrite(ignition, HIGH);
55     } 
56     else { 
57     digitalWrite(ignition,  LOW);
58  } 
59  
60  Serial.print(rpm_val);
61  delay(1);        // delay in  between reads for stability
62}
63

1// Rev-Limiter Code for Arduino Project Hub
2//
3//Written by Adrianos
4  Botis: adrianosbotis@gmail.com
5//
6//Use at your own and change the parameters:
7  rpm_val to set the rpm limit of your engine.
8//You can also change the delay
9  of milliseconds at the end of the code to set how fast your engine will be switched
10  on-off.
11//
12
13
14int sensor_pin = 3;
15// set number of hall trips for
16  RPM reading (higher improves accuracy)
17float sensor_thresh = 5.0;
18int ignition
19  = 2;
20
21void setup() {
22  // initialize serial communication at 9600 bits
23  per second:
24  Serial.begin(9600);
25  // make the sensor pin an input:
26  pinMode(sensor_pin,
27  INPUT);
28  pinMode(ignition, OUTPUT);
29}
30
31// this loop routine runs over
32  and over again forever:
33void loop() {
34  // preallocate values for tach
35
36  float hall_count = 1.0;
37  float start = micros();
38  bool on_state = false;
39
40  // counting number of times the hall sensor is tripped
41  // but without double
42  counting during the same trip
43  while(true){
44    if (digitalRead(sensor_pin)
45  == 1){
46      if (on_state==false){
47        on_state = true;
48        hall_count+=1.0;
49
50      }
51    } else{
52      on_state = false;
53    }
54    
55    if (hall_count>=sensor_thresh){
56
57      break;
58    }
59  }
60  
61  // print information about Time and RPM
62
63  float end_time = micros();
64  float time_passed = ((end_time-start)/1000000.0);
65
66  Serial.print("Time Passed: ");
67  Serial.print(time_passed);
68  Serial.println("s");
69
70  float rpm_val = (sensor_thresh/(2*time_passed))*60.0;
71   if(rpm_val > 8000.0){
72
73     digitalWrite(ignition, HIGH);
74     } 
75     else { 
76     digitalWrite(ignition,
77  LOW);
78  } 
79  
80  Serial.print(rpm_val);
81  delay(1);        // delay in
82  between reads for stability
83}
84