Digital tube with Traffic Light Experiment

This lesson will use the 74HC595 shift register in combination with the red and green LEDs and the yellow LED to create a traffic light.

Component Required

• 1 x Uno R3

• 1 x 830 tie-points breadboard

• 1 x 1 Digit 7-Segment Display

• 10 X 220 ohm resistors

• 20 x M-M wire (Male to Male jumper wire)

• 1 x Red LED

• 1 x Yellow LED

• 1 x Green LED

Component Introduction

Seven segment display

Below is the seven-segment pin diagram.

0-9 ten digits correspond with each segment are as follows (the following table applies common cathode seven segment display device, if you are using a common anode, the table should be replaced every 1 0 0 should all replaced by 1):

Display	dp	a	b	c	d	e	f	g
digital
0	0	1	1	1	1	1	1	0
1	0	0	1	1	0	0	0	0
2	0	1	1	0	1	1	0	1
3	0	1	1	1	1	0	0	1
4	0	0	1	1	0	0	1	1
5	0	1	0	1	1	0	1	1
6	0	1	0	1	1	1	1	1
7	0	1	1	1	0	0	0	0
8	0	1	1	1	1	1	1	1
9	0	1	1	1	1	0	1	1

Connection Diagram:

Wiring schematic:

Physical wiring diagram:

int a = 7;
int b = 6;
int c = 5;
int d = 11;
int e = 10;
int f = 8;
int g = 9;

int ledG = 14;
int ledY = 15;
int ledR = 16;

//Display number 1
void digital_1(void)
{
  unsigned char j;
  digitalWrite(c, HIGH); //Lower the level of the digital 5 pin and light up segment c
  digitalWrite(b, HIGH); //Light section b
  for (j = 7; j <= 11; j++) //blanking
    digitalWrite(j, LOW);
}
//Display number 2
void digital_2(void)
{
  unsigned char j;
  digitalWrite(b, HIGH);
  digitalWrite(a, HIGH);
  for (j = 9; j <= 11; j++)
    digitalWrite(j, HIGH);
  digitalWrite(c, LOW);
  digitalWrite(f, LOW);
}
//Display number 3
void digital_3(void)
{
  unsigned char j;
  digitalWrite(g, HIGH);
  digitalWrite(d, HIGH);
  for (j = 5; j <= 7; j++)
    digitalWrite(j, HIGH);
  digitalWrite(f, LOW);
  digitalWrite(e, LOW);
}


//Display number 4
void digital_4(void)
{
  digitalWrite(c, HIGH);
  digitalWrite(b, HIGH);
  digitalWrite(f, HIGH);
  digitalWrite(g, HIGH);
  digitalWrite(a, LOW);
  digitalWrite(e, LOW);
  digitalWrite(d, LOW);
}
//Display number 5
void digital_5(void)
{
  unsigned char j;
  for (j = 7; j <= 9; j++)
    digitalWrite(j, HIGH);
  digitalWrite(c, HIGH);
  digitalWrite(d, HIGH);
  digitalWrite(b, LOW);
  digitalWrite(e, LOW);
}
//Display number 6
void digital_6(void)
{
  unsigned char j;
  for (j = 7; j <= 11; j++)
    digitalWrite(j, HIGH);
  digitalWrite(c, HIGH);
  digitalWrite(b, LOW);
}
//Display number 7
void digital_7(void)
{
  unsigned char j;
  for (j = 5; j <= 7; j++)
    digitalWrite(j, HIGH);
  for (j = 8; j <= 11; j++)
    digitalWrite(j, LOW);
}

//Display number 8
void digital_8(void)
{
  unsigned char j;
  for (j = 5; j <= 11; j++)
    digitalWrite(j, HIGH);
}
//Display number 9
void digital_9(void)
{
  digitalWrite(c, HIGH);
  digitalWrite(b, HIGH);
  digitalWrite(f, HIGH);
  digitalWrite(g, HIGH);
  digitalWrite(a, HIGH);
  digitalWrite(e, LOW);
  digitalWrite(d, HIGH);
}
//Pin setting and initialization
void setup()
{
  int i;//defined variable
  for (i = 5; i <= 16; i++)
    pinMode(i, OUTPUT); //Set pins 5 ~ 16 to output mode

}

void loop()
{
  while (1)
  {
    //red light
    digitalWrite(ledR, LOW);
    digitalWrite(ledY, HIGH);
    digitalWrite(ledG, HIGH);

    digital_9();  // Show 9
    delay(1000);   //Delay 1 s
    digital_8();  // Show 8
    delay(1000);   //Delay 1 s
    digital_7();  // Show 7
    delay(1000);   //Delay 1 s
    digital_6();  // Show 6
    delay(1000);   //Delay 1 s
    digital_5();  // Show 5
    delay(1000);   //Delay 1 s
    digital_4();  // Show 4
    delay(1000);   //Delay 1 s
    digital_3();  // Show 3
    delay(1000);   //Delay 1 s
    digital_2();  // Show 2
    delay(1000);   //Delay 1 s
    digital_1();  // Show 1
    delay(1000);   //Delay 1 s
    //green light
    digitalWrite(ledR, HIGH);
    digitalWrite(ledY, HIGH);
    digitalWrite(ledG, LOW);

    digital_9();  // Show 9
    delay(1000);   //Delay 1 s
    digital_8();  // Show 8
    delay(1000);   //Delay 1 s
    digital_7();  // Show 7
    delay(1000);   //Delay 1 s
    digital_6();  // Show 6
    delay(1000);   //Delay 1 s
    digital_5();  // Show 5
    delay(1000);   //Delay 1 s
    digital_4();  // Show 4
    delay(1000);   //Delay 1 s
    digital_3();  // Show 3
    delay(1000);   //Delay 1 s
    digital_2();  // Show 2
    delay(1000);   //Delay 1 s
    digital_1();  // Show 1
    delay(1000);   //Delay 1 s
    //yellow light
    digitalWrite(ledR, HIGH);
    digitalWrite(ledY, LOW);
    digitalWrite(ledG, HIGH);
    digital_3();  // Show 3
    delay(1000);   //Delay 1 s
    digital_2();  // Show 2
    delay(1000);   //Delay 1 s
    digital_1();  // Show 1
    delay(1000);   //Delay 1 s
  }
}

digialtube-traffic-light.ino

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