Rover for Cave Exploration

1#include <dht.h>
2#define dataPin 8 // Defines pin number to which the  sensor is connected
3char bt;
4int trig_pin = 12;
5int echo_pin = 9;
6int  airquality = A3 ;
7dht DHT; // Creats a DHT object
8long echotime; //in micro  seconds
9float distance; //in cm
10unsigned long interval=2000;     // the time  we need to wait
11unsigned long previousMillis=0;  // millis() returns an unsigned  long.
12
13void setup() {
14  Serial.begin (9600);
15  pinMode(2,OUTPUT);   //left  motors forward
16  pinMode(3,OUTPUT);   //left motors reverse
17  pinMode(4,OUTPUT);   //right motors forward
18  pinMode(7,OUTPUT);   //right motors reverse
19  pinMode(trig_pin,  OUTPUT); 
20  pinMode(echo_pin, INPUT);
21  digitalWrite(trig_pin, LOW); //Start  with trigger LOW
22}
23
24void loop() {
25  if(Serial.available()){
26  bt  = Serial.read();
27  Serial.println(bt);
28}
29
30if(bt == 'F'){            //move  forward(all motors rotate in forward direction)
31  digitalWrite(2,HIGH);
32  digitalWrite(3,LOW);
33  digitalWrite(4,HIGH);
34  digitalWrite(7,LOW);
35}
36 
37else if(bt == 'B'){      //move reverse (all motors rotate in reverse direction)
38  digitalWrite(2,LOW);
39  digitalWrite(3,HIGH);
40  digitalWrite(4,LOW);
41  digitalWrite(7,HIGH);
42}
43  
44else if(bt == 'L'){      //turn right (left side motors rotate in forward direction,  right side motors rotate in reverse direction)
45  digitalWrite(2,LOW);
46  digitalWrite(3,HIGH);
47  digitalWrite(4,HIGH);
48  digitalWrite(7,LOW);
49}
50 
51else if(bt == 'R'){      //turn left (right side motors rotate in forward direction, left side motors  rotate in reverse direction)
52  digitalWrite(2,HIGH);
53  digitalWrite(3,LOW);
54  digitalWrite(4,LOW);
55  digitalWrite(7,HIGH);
56}
57 
58else if(bt == 'S'){      //STOP (all motors stop)
59  digitalWrite(2,LOW);
60  digitalWrite(3,LOW);
61  digitalWrite(4,LOW);
62  digitalWrite(7,LOW);
63}
64
65unsigned long currentMillis  = millis(); // grab current time
66 
67 // check if "interval" time has passed  (2000 milliseconds)
68 if ((unsigned long)(currentMillis - previousMillis) >= interval)  {
69 
70  //trigger a pulse-echo measurement
71  digitalWrite(trig_pin, HIGH);
72  delayMicroseconds(10);
73  digitalWrite(trig_pin, LOW);
74
75  //get the result
76  echotime= pulseIn(echo_pin, HIGH);
77  distance= (0.0001*((float)echotime*340.0)/2.0);
78  
79  //send over Bluetooth 
80  Serial.print("|");
81  Serial.print(distance);
82
83  int readData = DHT.read22(dataPin); // Reads the data from the sensor
84  float  t = DHT.temperature; // Gets the values of the temperature
85  float h = DHT.humidity;  // Gets the values of the humidity
86  
87  // Printing the results on the serial  monitor
88  Serial.print("|");
89  Serial.print(t);
90  Serial.print("|");
91  Serial.print(h);
92
93  //Read Analog pin 5 for sensor MQ 135 data
94  int  sensorValueMQ135 = analogRead(A3);
95
96  //send over Bluetooth
97  Serial.print("|");
98  Serial.print(sensorValueMQ135);
99
100  //Get MQ 5 sensor data
101  float sensor_volt;
102  float sensorValueMQ5;
103  sensorValueMQ5 = analogRead(A4);
104  
105  
106  //send  over Bluetooth
107  Serial.print("|");
108  Serial.print(sensorValueMQ5);
109  
110  previousMillis = millis();
111  }
112
113
114}