4 character 7-segment common cathode display

Basic decode for 4 character 7-segment common cathode display. 57-1093, anodes connected to Port D and segments controlled from port C0-C3.

//
// main.c - A simple example 7-segment LED control program.
// This program use a Table Lookup approach to decode a 7-segment LED
// multi-digit LED dsiplay.
//
// Written by Richard HAyes  - last modified 23-03-2012
//

// The following header file defines various values that are
// relevant to this chip, such as port names, etc
#include "p18f4620.h"

// Configure some global chip settings, such as oscillator type and clock speed
//
#pragma config OSC = INTIO67    // Sets the oscillator mode to HS
#pragma config WDT = OFF        // Turns the watchdog timer off
#pragma config MCLRE = OFF        // Turns low voltage programming off

// Configure Pins.
void configure_pins(void);

void main(void)
{
// Declare variables
int n;
int delay = 8;
char    LUT[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x67};
int    number[4]={1,2,3,5};
int    N=3;
int    M=4;
int    L=8;
int    K=1;
LATC=0x0f;

// Configure which pins are inputs and which are outputs
configure_pins();

while(1)
{
LATC=0x0f;                    // All Digits off
LATD = LUT[number[0]];
LATCbits.LATC3=0;            // Most Significant Digit
for (n=0 ; n<delay ; ++n);    // delay
LATC=0x0f;                    // All Digits off
LATD = LUT[number[1]];
LATCbits.LATC2=0;            // Next Significant Digit
for (n=0 ; n<delay ; ++n);    // delay
LATC=0x0f;                    // All Digits off
LATD = LUT[number[2]];
LATCbits.LATC1=0;            // Next Significant Digit
for (n=0 ; n<delay ; ++n);    // delay
LATC=0x0f;                    // All Digits off
LATD = LUT[number[3]];
LATCbits.LATC0=0;            // Next Significant Digit
for (n=0 ; n<delay ; ++n);    // delay

/*        LATD = 0x00;                // Blank
LATC=0b00000001;            // MS Digit
LATD = LUT[L];                // Least Significant Digit
for (n=0 ; n<delay ; ++n);    // delay
LATD = 0x00;                // Blank
//        LATC=0b00000010;            // MS Digit*/

}
}

// Function to configure digital I/O pins etc.
// This fucntion only configures port D so far - later on,
// you will need to configure settings for other pins on
// the chip.
void configure_pins()
{
// Configure port C digital inputs and outputs
// Inputs:  15, 16, 17, 18 (RC0, RC1, RC2 and RC3)
// Outputs: 19, 20, 21 and 22 (RD0, RD1, RD2 and RD3)
LATC = 0; // Set port C data latch, so that any pins that any outputs pins will be 0V initially.
TRISC = 0b11110000; // This binary value sets pins C0-3 as outputs and RC4-7 as inputs.
// Configure port D digital i/o
// Outputs: 19, 20, 21 and 22 27, 28, 29 and 30(RD0, RD1, RD2, RD3,RD4, RD5, RD6 and RD7)
LATD = 0; // Set port D data latch, so that any pins that any outputs pins will be 0V initially.
TRISD = 0b00000000; // This binary value sets pins RD0-7 as outputs.
}

Filed under: Displays