Push-up Counter using Arduino and Ultrasonic Sensor

1#include <TM1637Display.h>
2//HC-SR04
3#define echoPin  2
4#define
5  trigPin  3
6#define resetPin 4
7
8// 4-digital display pins (Digital Pins)
9#define
10  CLK 8
11#define DIO 9
12TM1637Display display(CLK, DIO);
13
14float duration;
15  //micro second
16float d_cm;
17long numDisplay=100;
18boolean trigUp = false;
19boolean
20  trigDown = false;
21float counterPushUp=0;
22
23void setup() {
24
25// initialize
26  serial communication:
27  Serial.begin(9600);
28  pinMode(trigPin,OUTPUT);
29
30  pinMode(echoPin,INPUT);
31  //
32  pinMode(resetPin,INPUT_PULLUP);
33  //
34
35  display.setBrightness(4);
36  display.clear();
37  delay(500);
38  display.showNumberDecEx(numDisplay,
39  false, true, 4, 0);
40}
41
42void loop() {
43  
44  //reset by switch
45  if(digitalRead(resetPin)==0){
46
47    trigUp=false;
48    trigDown=false;
49    counterPushUp=0;
50  }
51  
52
53  // generate pusle trigger
54  digitalWrite(trigPin,LOW);
55  delayMicroseconds(2);
56
57  digitalWrite(trigPin,HIGH);
58  delayMicroseconds(10);
59  digitalWrite(trigPin,LOW);
60
61  // receive, convert time (us) to cm
62  duration = pulseIn(echoPin,HIGH);
63
64  d_cm = duration * 0.034/2.;
65  
66  //trigger body 
67  if (d_cm>15 && d_cm<=30){
68
69    trigUp = true;
70  } else if (d_cm < 10){
71    trigDown = true;
72  } else
73  if(d_cm >30) {
74  }
75  //counter
76  if (trigUp==true && trigDown==true){
77
78    counterPushUp=counterPushUp+0.5;
79    trigUp=false;
80    trigDown=false;
81
82  }
83  //print
84//  Serial.print(d_cm);
85//  Serial.print(" --- ");
86//
87  Serial.println(counterPushUp);
88  display.showNumberDecEx(counterPushUp, false,
89  true, 4, 0);
90}
91