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[SOLVED] Problem with displaying the time, by using a RTC_PCF8583

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mariuszoll

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Hi,

I use on my project a PIC18F4550, and a RTC PCF8583. I use the HyperTerminal to read date and time. I would like to improve the time display, because when seconds and, minutes for instance excced the value of 59 there is displayed a blank, instead of value of 0.
Below you can see what I meant:
10:01:59
10:02:
10:02:01

Could you help me please to improve it?

Thank you in advance.
mariuszoll
 

You will have to tell us in what language the program is written. If you are using 'C' try changing the seconds format to %2d if it is just %d at the moment.

Brian.
 

Hi,

I use C in order to program the uC, and the tool is MPLAB.
How can I change the format to %2d?

Thank you.
Marius
 

You will have to show the code you are using. The standard text formatting commands are 'printf' and 'sprintf' which contain formatting parameters. If these are what you are using, you should see a version of what you are transmitting with %d substituted where the digits should be, something like "%d:%d:%d". Adding a number between the '%' and 'd' tells it how many digits should be displayed, in your case you want it to be 2 so in the absence of any other digits it shows two zeroes instead of nothing at all.

You will have to post the code to be sure though.

Brian.
 

I would like to improve the time display

Sure , just add 00 to convert 10:02: to 10:02:00 :shock:

What kind of help do you expect when you have shown none of the code that is responsible for this
 

Here you have attached the C code:

Code:
#include <p18f4550.h>
#include <delays.h>
#include <sw_uart.h>
#include <i2c.h>

// Pragma, internal register configuration

#pragma config FOSC = INTOSCIO_EC	//Internal oscillator, port function on RA6, EC used by USB 
#pragma config WDT = OFF			// watch dog disabled
#pragma config IESO = OFF			//Oscillator Switchover mode disabled 
//#pragma config PWRT = OFF  			//PWRT disabled   	
#pragma config BORV = 2				// output voltage test 2V
#pragma config PBADEN=OFF			//PORTB<4:0> pins are configured as digital I/O on Reset 
#pragma config STVREN=OFF			//Stack full/underflow will not cause Reset 
#pragma config LVP=OFF				//Single-Supply ICSP disabled 
#pragma config XINST=OFF			//Instruction set extension and Indexed Addressing mode disabled (Legacy mode)


// definitions

#define PCF8583_WRITE_ADDRESS 0xA0 
#define PCF8583_READ_ADDRESS  0xA1 

// Register addresses 
#define PCF8583_CTRL_STATUS_REG    0x00 
#define PCF8583_100S_REG           0x01 
#define PCF8583_SECONDS_REG        0x02 
#define PCF8583_MINUTES_REG        0x03 
#define PCF8583_HOURS_REG          0x04 
#define PCF8583_DATE_REG           0x05 
#define PCF8583_MONTHS_REG         0x06 
#define PCF8583_TIMER_REG          0x07 

#define PCF8583_ALARM_CONTROL_REG  0x08 
#define PCF8583_ALARM_100S_REG     0x09 
#define PCF8583_ALARM_SECS_REG     0x0A 
#define PCF8583_ALARM_MINS_REG     0x0B 
#define PCF8583_ALARM_HOURS_REG    0x0C 
#define PCF8583_ALARM_DATE_REG     0x0D 
#define PCF8583_ALARM_MONTHS_REG   0x0E 
#define PCF8583_ALARM_TIMER_REG    0x0F 

// Use the first NVRAM address for the year byte. 
#define PCF8583_YEAR_REG           0x10 


// Commands for the Control/Status register. 
#define PCF8583_START_COUNTING     0x00 
#define PCF8583_STOP_COUNTING      0x80 

// Variables
unsigned char seconds=0x00,minutes=0x00,hours=0x00,day=0x00,month=0x00,year=0x00;

/** L O C A L   F U N C T I O N S  *******************************************/

void init_UART(void)
{
	TXSTAbits.TX9=0;
	TXSTAbits.TXEN=1;
	TXSTAbits.SYNC=0;
	TXSTAbits.BRGH=1;
	TXSTAbits.TX9D=0;
	RCSTAbits.SPEN=1;
	BAUDCONbits.BRG16=0;
	SPBRG=25;			// 9600KBaud
}

// Read time and date information from RTC( PCF8583 )
void Read_Time(void)
{
	// read seconds
	StartI2C();
	while(SSPCON2bits.SEN);
	WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
	WriteI2C(PCF8583_SECONDS_REG);		// Start from seconds memory location
	RestartI2C();				// At this moment master transmitter becomes master receiver 
	while(SSPCON2bits.RSEN);		// and PCF8583 slave receiver becomes slave transmitter
	WriteI2C(PCF8583_READ_ADDRESS);		// Address and Read Flag
	seconds=ReadI2C();			// read seconds reg
	NotAckI2C();
	StopI2C();
	while(SSPCON2bits.PEN);

	// read minutes
	StartI2C();
	while(SSPCON2bits.SEN);
	WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
	WriteI2C(PCF8583_MINUTES_REG);		// Start from minutes memory location
	RestartI2C();				// At this moment master transmitter becomes master receiver 
	while(SSPCON2bits.RSEN);		// and PCF8583 slave receiver becomes slave transmitter
	WriteI2C(PCF8583_READ_ADDRESS);		// Address and Read Flag
	minutes=ReadI2C();			// read minutes reg
	NotAckI2C();
	StopI2C();
	while(SSPCON2bits.PEN);

	// read hours
	StartI2C();
	while(SSPCON2bits.SEN);
	WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
	WriteI2C(PCF8583_HOURS_REG);		// Start from hours memory location
	RestartI2C();				// At this moment master transmitter becomes master receiver 
	while(SSPCON2bits.RSEN);		// and PCF8583 slave receiver becomes slave transmitter
	WriteI2C(PCF8583_READ_ADDRESS);		// Address and Read Flag
	hours=ReadI2C();			// read hours reg
	NotAckI2C();
	StopI2C();
	while(SSPCON2bits.PEN);

	// read day
	StartI2C();
	while(SSPCON2bits.SEN);
	WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
	WriteI2C(PCF8583_DATE_REG);		// Start from year/date memory location
	RestartI2C();				// At this moment master transmitter becomes master receiver 
	while(SSPCON2bits.RSEN);		// and PCF8583 slave receiver becomes slave transmitter
	WriteI2C(PCF8583_READ_ADDRESS);		// Address and Read Flag
	day=ReadI2C();				// read year/date reg
	NotAckI2C();
	StopI2C();
	while(SSPCON2bits.PEN);

	// read month
	StartI2C();
	while(SSPCON2bits.SEN);
	WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
	WriteI2C(PCF8583_MONTHS_REG);		// Start from weekday/month memory location
	RestartI2C();				// At this moment master transmitter becomes master receiver 
	while(SSPCON2bits.RSEN);		// and PCF8583 slave receiver becomes slave transmitter
	WriteI2C(PCF8583_READ_ADDRESS);		// Address and Read Flag
	month=ReadI2C();			// read weekday/month reg
	NotAckI2C();
	StopI2C();
	while(SSPCON2bits.PEN);

}

//	Formats date and time
void Transform_Time()
{ 
  	seconds  =  ((seconds & 0xF0) >> 4)*10 + (seconds & 0x0F);  		// Transform seconds
  	minutes  =  ((minutes & 0xF0) >> 4)*10 + (minutes & 0x0F);  		// Transform months
  	hours    =  (((hours & 0xF0)  >> 4)*10  + (hours & 0x0F)) & 0x3F;     	// Transform hours
//	year     =   (day & 0xC0) >> 6;                             		// Transform year
  	day      =  (((day & 0x30) >> 4)*10    + (day & 0x0F)) & 0x3F;       	// Transform day
  	month    =  (((month & 0x10)  >> 4)*10 + (month & 0x0F)) & 0x3F;     	// Transform month
}

// This function converts an 8 bit binary value 
// to an 8 bit BCD value. 
// The input range must be from 0 to 99

unsigned char bin2bcd(unsigned x)
{
	unsigned char y;

	y=(x / 10) << 4;
	y= y | (x % 10);
	return(y);
} 

// This function converts an 8 bit BCD value to 
// an 8 bit binary value. 
// The input range must be from 00 to 99. 

unsigned bcd2bin(unsigned char x)
{ 

return (x & 0x0F) + (x >> 4)*10;

} 

void print_date_time(char t)
	{
		int k,n,j,m,c;
		unsigned char data;
		unsigned char string[5];

		data=t;
		n=data;
		j=0;

		while(n!=0)
		{
			c=n%10;
			n=n/10;
			string[j]=c+48;
			j++;
		}
			
		m=j-1;
			
		while(m>=0)
		{
			WriteUSART(string[m]);
			while(!TXSTAbits.TRMT);
			m--;
		}
	}	

///////////////////functia main///////////////////////////////////////////

void main(void)
 {
	
		//Outputs:

		TRISCbits.TRISC6=0;		// UART__TX
		
		//Inputs:

		TRISBbits.TRISB0=1;     // I2C_SDA
		TRISBbits.TRISB1=1;     // I2C_SCL
		TRISCbits.TRISC7=1;		// UART__RX

		// Oscillator frequency
	
		OSCCON=0b01100110;      // 4MHz
		
		// the configuration of the functions of port pins
		
		ADCON1=0b00001111;		// digital port configured
	
		// Initializations

		init_UART();
		TXREG=12;			// new page

		// I2C settings

		SSPSTAT=0x80;	// SLEW RATE CONTROL DISABLED FOR std mode (100khz)
		SSPCON1=0x28;	// i2c master mode, serial synch enable
		SSPCON2=0x00;
		SSPADD=0x09;	// for 100Khz
	 	
		// Set time and date

		StartI2C();
		while(SSPCON2bits.SEN);
		WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
		WriteI2C(PCF8583_CTRL_STATUS_REG);	// start from address 0 (control/status reg)
		WriteI2C(PCF8583_STOP_COUNTING);	// write 0x80 to control/status reg (stop counting)
		WriteI2C(0x00);				// write 0 to 100's memory location
		WriteI2C(0x00);				// write 0 to seconds memory location
		WriteI2C(0x02);				// write 0x18 to minutes memory location		
		WriteI2C(0x10);				// write 0x09 to hours memory location
		WriteI2C(0x06);				// write 0x18 to year/date memory location		
		WriteI2C(0x02);				// write 0x09 to weekday/month memory location
		StopI2C();
		while(SSPCON2bits.PEN);

		StartI2C();
		while(SSPCON2bits.SEN);
		WriteI2C(PCF8583_WRITE_ADDRESS);	// Address and Write Flag
		WriteI2C(PCF8583_CTRL_STATUS_REG);	// Start from address 0
		WriteI2C(PCF8583_START_COUNTING);	// write 0x00 to control/status reg (enable counting)
		StopI2C();
		while(SSPCON2bits.PEN);

	while(1) 
  		{	
			// Read the date and time from the PCF8583 and dispaly it once per second
			Delay10KTCYx(100);

			Read_Time();
			Transform_Time();
	
			print_date_time(hours);
			TXREG=58;			// :
			print_date_time(minutes);
			TXREG=58;			// :
			print_date_time(seconds);
			TXREG=32;			// space
			TXREG=32;			//space
			print_date_time(day);
			TXREG=47;			// /
			print_date_time(month);
			TXREG=10;  			// new line
			TXREG=13;			//carriage return  

		}
}  // main

MOD: PLEASE USE CODE TAGS
 
Last edited by a moderator:

This is where it all happens
Code:
void print_date_time(char t)
	{
		int k,n,j,m,c;
		unsigned char data;
		unsigned char string[5];

		data=t;
		n=data;
		j=0;

		[COLOR="#FF0000"]while(n!=0)
		{
			c=n%10;
			n=n/10;
			string[j]=c+48;
			j++;
		}[/COLOR]
			
		m=j-1;
			
		while(m>=0)
		{
			WriteUSART(string[m]);
			while(!TXSTAbits.TRMT);
			m--;
		}
	}

when the value you send to the function is 0 you never add any ASCII '0' to the array
 

Thank you very much alexan_e.

I added the following program sequence before while:
if(n==0)
{ WriteUSART('0');
while(!TXSTAbits.TRMT);
}

and it works well.

Thank you.
mariuszoll
 

Try simply removing the "while(n!=0)" and associated { and }. I presume the values being passed to it are normal numbers anyway.

Brian.
 

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