How to interface Seven Segment Display with PIC18F4550 Microcontroller- (Part 3/25)

The seven segments are used to display decimal and hexadecimal (0-9, A-F) values. A seven segment is cheapest option for applications requiring numeric value display as output. Calculators, watches, lift’s floor indication panel etc. are examples of such applications. The interfacing and operation of a seven-segment display with PIC18F4550 has been explained here.

A typical seven-segment consists of 8 LEDs arranged in a pattern to display values. A seven-segment can be either of the two types, namely, Common Anode (CA) and Common Cathode (CC). For more details, refer Seven segments.

A single seven-segment requires a minimum of 7 data pins of controller to display different values. The connections of seven-segment with PIC18F4550 are shown in the adjoining circuit.

To display a numeric value, a particular data-byte is sent by the microcontroller. Refer seven segment interfacing with 8051. This data byte can either be calculated manually or by using Seven Segment Editor tool of mikroC IDE. (Also see Working with mikroC)

Project Source Code

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// Program to Interface seven segment display with PIC18F4550 Microcontroller

// Configuration bits
/* _CPUDIV_OSC1_PLL2_1L,  // Divide clock by 2
   _FOSC_HS_1H,           // Select High Speed (HS) oscillator
   _WDT_OFF_2H,           // Watchdog Timer off
   MCLRE_ON_3H            // Master Clear on
*/

#define seg_port LATB
void main(void)
{
	TRISB=0;		// Configure PortB as output port
	while(1)
	{
		seg_port=0xC0;         // Display '0'
		Delay_ms(1000);
                    
		seg_port=0xF9;         // Display '1'
		Delay_ms(1000);
                    
		seg_port=0xA4;         // Display '2'
		Delay_ms(1000);
                    
		seg_port=0xB0;         // Display '3'
		Delay_ms(1000);
                    
		seg_port=0x99;         // Display '4'
		Delay_ms(1000);
                    
		seg_port=0x92;         // Display '5'
		Delay_ms(1000);
                    
		seg_port=0x82;         // Display '6'
		Delay_ms(1000);
                    
		seg_port=0xF8;         // Display '7'
		Delay_ms(1000);
                    
		seg_port=0x80;         // Display '8'
		Delay_ms(1000);
                    
		seg_port=0x90;         // Display '9'
		Delay_ms(1000);
	}
}

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