Build a 4-Bit Digital to Analog Convertor using Arduino UNO

1//feel free to experiment with the code by setting different inputs (1,  or 0) to the Digital Pins 
2
3//Digital to Analog Convertor Testing
4//For  a 4-bit DAC Circuit.
5
6//set the delay
7int timer = 100;
8
9void setup()  {
10    //set the Digital Pins- D2 to D6
11    for(int thisPin = 2; thisPin <  6; thisPin++){
12      pinMode(thisPin, OUTPUT);
13    }
14    Serial.begin(9600);
15}
16
17void  loop() {
18    //turns the 4 Digital pins into HIGH (1) state
19    //experiment  by changing the 4 pin values
20    for(int thisPin = 2; thisPin < 6; thisPin++){
21      digitalWrite(thisPin, HIGH);
22      delay(timer);
23    }
24    
25    int  sensorValue = analogRead(A0);
26    // convert the analog reading (which goes from  0 - 1023) to a voltage (0 - 5V):
27    float voltage = sensorValue * (5.0 / 1023.0);
28    
29    // print out the analog voltage value we read
30    Serial.println(voltage);
31    
32    //turn the pins off
33    for (int thisPin = 5; thisPin >= 2; thisPin--)  {
34      digitalWrite(thisPin, LOW);
35      delay(timer);
36    }
37    
38}