Tachometer

1// Tachometer with lcd i2c screen
2#include <Wire.h>
3#include <LiquidCrystal_I2C.h>
4LiquidCrystal_I2C
5  lcd(0x27, 16, 2);
6#define sensor_pin 2
7int READ = 0;
8int i = 0;
9bool
10  mask = 0;
11unsigned long timer = 0;
12float Time = 0.0;
13int RPM = 0;
14const
15  int revnum = 20;
16void setup()
17{
18  pinMode(sensor_pin, INPUT);
19  //  Wire.begin();
20
21  Serial.begin(115200);
22  lcd.begin();
23  lcd.backlight();
24  timer = millis();
25}
26
27void
28  loop()
29{
30  READ = digitalRead(sensor_pin);
31  if (READ == 0 && mask == 0)
32  {
33    i++;
34    mask = 1;
35  }
36  if (READ == 1 && mask == 1) mask = 0;
37
38  if (i == revnum) {
39    Time = millis() - timer;
40    Time = Time / 1000;
41
42    RPM = ( revnum / Time ) * 60;
43    lcd.clear();
44    lcd.setCursor(0, 0);
45
46    lcd.print(revnum);
47    lcd.setCursor(3, 0);
48    lcd.print( "revs / ");
49
50    lcd.setCursor(10, 0);
51    lcd.print(Time);
52    lcd.setCursor(15, 0);
53
54    lcd.print("s");
55    lcd.setCursor(0, 1);
56    lcd.print("RPM = ");
57
58    lcd.setCursor(6, 1);
59    lcd.print(RPM);
60    lcd.setCursor(12, 1);
61
62    lcd.print("rpm");
63  }
64  if (i >= revnum) {
65    i = 0;
66    timer
67  = millis();
68  }
69  Serial.print(i);
70  Serial.print("  ");
71  Serial.print(mask);
72
73  Serial.print("  ");
74  Serial.print(Time);
75  Serial.print("S");
76  Serial.print("
77  ");
78  Serial.print(RPM);
79  Serial.println("RPM");
80
81}
82

1// Tachometer with lcd i2c screen
2#include <Wire.h>
3#include <LiquidCrystal_I2C.h>
4LiquidCrystal_I2C  lcd(0x27, 16, 2);
5#define sensor_pin 2
6int READ = 0;
7int i = 0;
8bool  mask = 0;
9unsigned long timer = 0;
10float Time = 0.0;
11int RPM = 0;
12const  int revnum = 20;
13void setup()
14{
15  pinMode(sensor_pin, INPUT);
16  //  Wire.begin();
17  Serial.begin(115200);
18  lcd.begin();
19  lcd.backlight();
20  timer = millis();
21}
22
23void  loop()
24{
25  READ = digitalRead(sensor_pin);
26  if (READ == 0 && mask == 0)  {
27    i++;
28    mask = 1;
29  }
30  if (READ == 1 && mask == 1) mask = 0;
31  if (i == revnum) {
32    Time = millis() - timer;
33    Time = Time / 1000;
34    RPM = ( revnum / Time ) * 60;
35    lcd.clear();
36    lcd.setCursor(0, 0);
37    lcd.print(revnum);
38    lcd.setCursor(3, 0);
39    lcd.print( "revs / ");
40    lcd.setCursor(10, 0);
41    lcd.print(Time);
42    lcd.setCursor(15, 0);
43    lcd.print("s");
44    lcd.setCursor(0, 1);
45    lcd.print("RPM = ");
46    lcd.setCursor(6, 1);
47    lcd.print(RPM);
48    lcd.setCursor(12, 1);
49    lcd.print("rpm");
50  }
51  if (i >= revnum) {
52    i = 0;
53    timer  = millis();
54  }
55  Serial.print(i);
56  Serial.print("  ");
57  Serial.print(mask);
58  Serial.print("  ");
59  Serial.print(Time);
60  Serial.print("S");
61  Serial.print("  ");
62  Serial.print(RPM);
63  Serial.println("RPM");
64
65}
66