PSoC Lab 02: 4-Digit Seven Segment Display

Objective

• Learn how to interface 4-digit seven-segment display
• Learn proper configuration of the Segment LCD component

Required Reading Material

• Seven Segment Display

Background Information

A 4-digit seven-segment display has 12 pins; 8 of the pins are for the 8 LEDs on each of the seven-segment displays, which includes A ~ G and DP (decimal point). The other 4 pins represent each of the 4 digits from D1 ~ D4. The pinout for the 4-digit seven-segment display is shown below.

Figure 1: The Pinout for 4-Digit Seven-Segment Display

Required Components List

	4-Digit Seven Segment Display	x 1
	Push Button	x 1
	Resistor: 220 ohm	x 8

Circuit / Schematic Diagram

Procedure

Check Lists

FIll the following configuration information into the report

• Port.Pin configuration:
  

  Device	Port.Pin	Signal Type	Direction:	Drive Mode

TopDesign and PSoC Components

Add the following PSoC Creator components in the TopDesign:

Figure 1: TopDesign.cysch

• Display ➤ 4 Digit 7-Segment LED Driver
• Ports and Pins ➤ Digital Input Pin

Sample Code

main.c

#include "project.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>

int main(void)
{
    uint16_t    count = 0;
    
    CyGlobalIntEnable; /* Enable global interrupts. */

    /* Place your initialization/startup code here (e.g. MyInst_Start()) */
    LED_Start();
    LED_Write7SegNumberDec(count, 0, 4, LED_RIGHT_ALIGN);

    for(;;)
    {
        /* Place your application code here. */
        if (!nSW_Read()){
            count++;
            LED_Write7SegNumberDec(count, 0, 4, LED_RIGHT_ALIGN); // Display a number from com0 for 4 digits
            CyDelay(250);
        }
    }
}

When you press and hold the SW, the system will count up from 0 to 9999. When you release SW, the system will stop counting.

Questions

1. What type of seven-segment display that you used in this lab? Common Anode (CA) or Common Cathode (CC)? How to identify it without using a multimeter and search from datasheet or internet?
2. What number will be displayed on the 4-digit seven-segment LCD for the following code?
   uint32_t    count32 = 123456;
   LED_Write7SegNumberDec(count32, 0, 4, LED_RIGHT_ALIGN);

Exercises