Sending Commands from Host to Uno

1//Send commands from Serial Monitor to Arduino Uno Rev3
2
3//variable  declarations
4int RXdata = 0; 
5
6void setup() {
7  // put your setup code  here, to run once:
8  //set pins 2-5 as output for LEDs
9  for (int i = 2; i  < 6; i++){
10    pinMode(i, OUTPUT);
11  }
12
13  Serial.begin(9600);   //configure  serial port to 9600 baud
14}
15
16void loop() {
17  // put your main code here,  to run repeatedly:
18
19  if(Serial.available() > 0){   //check if any data was  received
20    RXdata = Serial.read();
21    Serial.print(RXdata, DEC);
22
23    switch(RXdata){
24      case '0':
25        //set LEDs to 0000
26        digitalWrite(2,  LOW);
27        digitalWrite(3, LOW);
28        digitalWrite(4, LOW);
29        digitalWrite(5,  LOW);
30        break;
31      case '1':
32        //set LEDs to 0001
33        digitalWrite(2,  HIGH);
34        digitalWrite(3, LOW);
35        digitalWrite(4, LOW);
36        digitalWrite(5,  LOW);
37        break;
38      case '2':
39        //set LEDs to 0010
40        digitalWrite(2,  LOW);
41        digitalWrite(3, HIGH);
42        digitalWrite(4, LOW);
43        digitalWrite(5,  LOW);
44        break;
45      case '3':
46        //set LEDs to 0011
47        digitalWrite(2,  HIGH);
48        digitalWrite(3, HIGH);
49        digitalWrite(4, LOW);
50        digitalWrite(5,  LOW);
51        break;
52      case '4':
53        //set LEDs to 0100
54        digitalWrite(2,  LOW);
55        digitalWrite(3, LOW);
56        digitalWrite(4, HIGH);
57        digitalWrite(5,  LOW);
58        break;
59      case '5':
60        //set LEDs to 0101
61        digitalWrite(2,  HIGH);
62        digitalWrite(3, LOW);
63        digitalWrite(4, HIGH);
64        digitalWrite(5,  LOW);
65        break;
66      case '6':
67        //set LEDs to 0110
68        digitalWrite(2,  LOW);
69        digitalWrite(3, HIGH);
70        digitalWrite(4, HIGH);
71        digitalWrite(5,  LOW);
72        break;
73      case '7':
74        //set LEDs to 0111
75        digitalWrite(2,  HIGH);
76        digitalWrite(3, HIGH);
77        digitalWrite(4, HIGH);
78        digitalWrite(5,  LOW);
79        break;
80      case '8':
81        //set LEDs to 1000
82        digitalWrite(2,  LOW);
83        digitalWrite(3, LOW);
84        digitalWrite(4, LOW);
85        digitalWrite(5,  HIGH);
86        break;
87      case '9':
88        //set LEDs to 1001
89        digitalWrite(2,  HIGH);
90        digitalWrite(3, LOW);
91        digitalWrite(4, LOW);
92        digitalWrite(5,  HIGH);
93        break;
94    }
95  }
96
97}