# Four digit tube display

### **Overview**

When using 1-digit 7-segment display, please notice that if it is common anode, the common anode pin connects to the power source; if it is common cathode, the common cathode pin connects to the GND.

When using 4-digit 7-segment display, the common anode or common cathode pin is used to control which digit is displayed. Even though there is only one digit working, the principle of Persistence of Vision enables you to see all numbers displayed because each the scanning speed is so fast that you hardly notice the intervals.

![](/files/1lZTGnJ0TScdS47GaPd3)

### **Component Required:**

* 1 x Arduino Uno R3
* 1 x 830 tie-points breadboard
* 1 x 74HC595 IC
* 1 x 4 Digit 7-Segment Display
* 4 x 220 ohm resistors
* 23 x M-M wires (Male to Male jumper wires)

### **Component Introduction**

#### **Four Digital Seven segment display**

![](/files/lPMkXCfXl1KLhdgTfViC)

### **Connection Diagram:**

![](/files/wO3f0G3iKSz1bgloQSdh)

### **Wiring schematic:**

![](/files/tpYrzkPOREmcEL6nJgDe)

### **Physical wiring diagram:**

![](/files/9AY7gbMCz5dacG12ueUJ)

### **Code:**

```
int latch = 9; //74HC595  pin 9 STCP
int clock = 10; //74HC595  pin 10 SHCP
int data = 8; //74HC595  pin 8 DS

unsigned char table[] =
{ 0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f, 0x77, 0x7c
  , 0x39, 0x5e, 0x79, 0x71, 0x00
};

void setup() {
  pinMode(latch, OUTPUT);
  pinMode(clock, OUTPUT);
  pinMode(data, OUTPUT);
}
void Display(unsigned char num)
{

  digitalWrite(latch, LOW);
  shiftOut(data, clock, MSBFIRST, table[num]);
  digitalWrite(latch, HIGH);

}
void loop() {
  Display(1);
  delay(500);
  Display(2);
  delay(500);
  Display(3);
  delay(500);
  Display(4);
  delay(500);
  Display(5);
  delay(500);
  Display(6);
  delay(500);
  Display(7);
  delay(500);
  Display(8);
  delay(500);
  Display(9);
  delay(500);
  Display(10);
  delay(500);
  Display(11);
  delay(500);
  Display(12);
  delay(500);
  Display(13);
  delay(500);
  Display(14);
  delay(500);
  Display(15);
  delay(500);
}
```

{% file src="/files/VSq0hVZpkIbVLHd2TIrx" %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://learn.arduinosa.co.za/arduino-kits/basic-starter-kit/four-digit-tube-display.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.