I2C not working in PIC18F46K22 using DS3231 - c

Question

I'm using PIC18F46K22 to display the time from DS3231 rtc device via I2C. I'm facing issue while setting the acknowledgement (ACKEN). I'm feeling something wrong in my configuration especially in Pin Configuration and setting the baud rate with SSP1ADD.
I'm using 20MHz and my DS3231 is supports for 400kHz.
While setting the acknowledgement(ACKEN), program getting hang, I mean, it is not able to set it not coming out from the step.
Please help me to fix the issue, please find the attached code.
//PCI18F46K22 Pin Configurations:
#define _XTAL_FREQ 20000000
// CONFIG1H
#pragma config FOSC = HSHP // Oscillator Selection bits->HS oscillator (high power > 16 MHz)
// PLLCFG changed
#pragma config PLLCFG = OFF // 4X PLL Enable->Oscillator used directly
// PRICLKEN changed
#pragma config PRICLKEN = OFF // Primary clock enable bit->Primary clock is always enabled
#pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable bit->Fail-Safe Clock Monitor disabled
#pragma config IESO = OFF // Internal/External Oscillator Switchover bit->Oscillator Switchover mode disabled
// CONFIG2L
// - PWRTEN
#pragma config PWRTEN = ON // Power-up Timer Enable bit->Power up timer disabled
// - BOREN = SBORDIS
#pragma config BOREN = ON // Brown-out Reset Enable bits->Brown-out Reset enabled in hardware only (SBOREN is disabled)
#pragma config BORV = 190 // Brown Out Reset Voltage bits->VBOR set to 1.90 V nominal
// CONFIG2H
#pragma config WDTEN = OFF // Watchdog Timer Enable bits->Watch dog timer is always disabled. SWDTEN has no effect.
#pragma config WDTPS = 32768 // Watchdog Timer Postscale Select bits->1:32768
// CONFIG3H
#pragma config CCP2MX = PORTC1 // CCP2 MUX bit->CCP2 input/output is multiplexed with RC1
#pragma config PBADEN = OFF // PORTB A/D Enable bit->PORTB<5:0> pins are configured as digital I/O on Reset
#pragma config CCP3MX = PORTB5 // P3A/CCP3 Mux bit->P3A/CCP3 input/output is multiplexed with RB5
#pragma config HFOFST = ON // HFINTOSC Fast Start-up->HFINTOSC output and ready status are not delayed by the oscillator stable status
#pragma config T3CMX = PORTC0 // Timer3 Clock input mux bit->T3CKI is on RC0
#pragma config P2BMX = PORTC0 // ECCP2 B output mux bit->P2B is on RC0
#pragma config MCLRE = EXTMCLR // MCLR Pin Enable bit->MCLR pin enabled, RE3 input pin disabled
// CONFIG4L
#pragma config STVREN = ON // Stack Full/Underflow Reset Enable bit->Stack full/underflow will cause Reset
#pragma config LVP = ON // Single-Supply ICSP Enable bit->Single-Supply ICSP enabled if MCLRE is also 1
#pragma config XINST = OFF // Extended Instruction Set Enable bit->Instruction set extension and Indexed Addressing mode disabled (Legacy mode)
#pragma config DEBUG = OFF // Background Debug->Disabled
// CONFIG5L
#pragma config CP0 = OFF // Code Protection Block 0->Block 0 (000800-003FFFh) not code-protected
#pragma config CP1 = OFF // Code Protection Block 1->Block 1 (004000-007FFFh) not code-protected
#pragma config CP2 = OFF // Code Protection Block 2->Block 2 (008000-00BFFFh) not code-protected
#pragma config CP3 = OFF // Code Protection Block 3->Block 3 (00C000-00FFFFh) not code-protected
// CONFIG5H
#pragma config CPB = OFF // Boot Block Code Protection bit->Boot block (000000-0007FFh) not code-protected
#pragma config CPD = OFF // Data EEPROM Code Protection bit->Data EEPROM not code-protected
// CONFIG6L
#pragma config WRT0 = OFF // Write Protection Block 0->Block 0 (000800-003FFFh) not write-protected
#pragma config WRT1 = OFF // Write Protection Block 1->Block 1 (004000-007FFFh) not write-protected
#pragma config WRT2 = OFF // Write Protection Block 2->Block 2 (008000-00BFFFh) not write-protected
#pragma config WRT3 = OFF // Write Protection Block 3->Block 3 (00C000-00FFFFh) not write-protected
// CONFIG6H
#pragma config WRTC = OFF // Configuration Register Write Protection bit->Configuration registers (300000-3000FFh) not write-protected
#pragma config WRTB = OFF // Boot Block Write Protection bit->Boot Block (000000-0007FFh) not write-protected
#pragma config WRTD = OFF // Data EEPROM Write Protection bit->Data EEPROM not write-protected
// CONFIG7L
#pragma config EBTR0 = OFF // Table Read Protection Block 0->Block 0 (000800-003FFFh) not protected from table reads executed in other blocks
#pragma config EBTR1 = OFF // Table Read Protection Block 1->Block 1 (004000-007FFFh) not protected from table reads executed in other blocks
#pragma config EBTR2 = OFF // Table Read Protection Block 2->Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks
#pragma config EBTR3 = OFF // Table Read Protection Block 3->Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks
// CONFIG7H
#pragma config EBTRB = OFF // Boot Block Table Read Protection bit->Boot Block (000000-0007FFh) not protected from table reads executed in other blocks
//-----------------------------
//--I2C Configurations
void I2C_Initialize(const unsigned long feq_K) //Begin IIC as master
{
TRISC3 = 1; //Set SCL pint as input pin
TRISC4 = 1; //Set SDA pin as input pin
ANSELCbits.ANSC3=0; //Disable Analog pin
ANSELCbits.ANSC4=0; //Disable Analog pin
SSP1CON1=0b00101000;; /* 0x00101000 - Enable SSP port for I2C Master mode, clock = FOSC / (4 * (SSPADD+1))*/
SSP1CON2=0b00000000;
SSP1CON3=0b00000000;
SSP1STAT=0b00000000;
SSP1ADD=(_XTAL_FREQ/(4*feq_K*100))-1;
}
void I2C_Hold()
{
while ( (SSP1CON2 & 0b00011111) || (SSP1STAT & 0b00000100) ) ; //check the bis on registers to make sure the IIC is not in progress
}
void I2C_Begin()
{
I2C_Hold(); //Hold the program is I2C is busy
SSP1CON2bits.SEN = 1;
}
void I2C_End()
{
I2C_Hold(); //Hold the program is I2C is busy
SSP1CON2bits.PEN = 1;
}
void I2C_Write(unsigned data)
{
I2C_Hold(); //Hold the program is I2C is busy
SSP1BUF = data;
}
unsigned short I2C_Read(unsigned short ack)
{
unsigned short incoming;
I2C_Hold();
SSP1CON2bits.RCEN = 1;
I2C_Hold();
incoming = SSP1BUF; //get the data saved in SSP1BUF
I2C_Hold();
SSP1CON2bits.ACKDT = (ack)?0:1; //check if ack bit received
SSP1CON2bits.ACKEN = 1;
return incoming;
}
//-------------------------------
//--DS3231 Functions to set/get timings
#include "i2c.h"
typedef struct
{
uint8_t sec;
uint8_t min;
uint8_t hour;
uint8_t weekDay;
uint8_t date;
uint8_t month;
uint8_t year;
}rtc_t;
void rtc_set_clock(rtc_t *rtc);
void get_date_time(rtc_t *rtc);
char* rtc_get_month(rtc_t *rtc);
/****** Functions for RTC module *******/
int BCD_2_DEC(int to_convert)
{
return (to_convert >> 4) * 10 + (to_convert & 0x0F);
}
int DEC_2_BCD (int to_convert)
{
return ((to_convert / 10) << 4) + (to_convert % 10);
}
void rtc_set_clock(rtc_t *rtc)
{
I2C_Begin();
I2C_Write(0xD0); //0x1101 0000
I2C_Write(0);
I2C_Write(DEC_2_BCD(rtc->sec)); //update sec
I2C_Write(DEC_2_BCD(rtc->min)); //update min
I2C_Write(DEC_2_BCD(rtc->hour)); //update hour
I2C_Write(1); //ignore updating day
I2C_Write(DEC_2_BCD(rtc->date)); //update date
I2C_Write(DEC_2_BCD(rtc->month)); //update month
I2C_Write(DEC_2_BCD(rtc->year)); //update year
I2C_End();
}
void get_date_time(rtc_t *rtc)
{
//START to Read
I2C_Begin();
I2C_Write(0xD0);
I2C_Write(0);
I2C_End();
//READ
I2C_Begin();
I2C_Write(0xD1); // Initialize data read
rtc->sec = BCD_2_DEC(I2C_Read(1));
rtc->min = BCD_2_DEC(I2C_Read(1)); // Read sec from register
rtc->hour = BCD_2_DEC(I2C_Read(1));
I2C_Read(1);
rtc->date = BCD_2_DEC(I2C_Read(1));
rtc->month = BCD_2_DEC(I2C_Read(1));
rtc->year = BCD_2_DEC(I2C_Read(1));
I2C_End();
//END Reading
I2C_Begin();
I2C_Write(0xD1); // Initialize data read
I2C_Read(1);
I2C_End();
return;
}
char* rtc_get_month(rtc_t *rtc) {
switch(rtc->month){
case 1: return "JAN";
case 2: return "FEB";
case 3: return "MAR";
case 4: return "APR";
case 5: return "MAY";
case 6: return "JUN";
case 7: return "JUL";
case 8: return "AUG";
case 9: return "SEP";
case 10: return "OCT";
case 11: return "NOV";
case 12: return "DEC";
}
return 0;
}
//------------------------
//My main function for PIC18F46K22 for DS3231 using I2C (SSP1)
rtc_t rtc;
void main()
{
char msg_welcome[15] = "LCD Read.";
char retValue[17];
char a,b;
short int i;
TRISC2 = 0;
LATC2 = 0;
PORTCbits.RC2 = 0;
I2C_Initialize(100);
Lcd_Init();
__delay_ms(5);
rtc.hour = 23; // 23:59:10 am
rtc.min = 59;
rtc.sec = 10;
rtc.date = 21; //21th Jan 2019
rtc.month = 1;
rtc.year = 19;
rtc_set_clock(&rtc);
Lcd_Clear();
Lcd_Write_String(1,1,"Start communic:");
Lcd_Write_String(2,1,"Timers:");
__delay_ms(1000);
LATC2 = 1;
Lcd_Clear();
while(1){
get_date_time(&rtc);
for(i=0; i< 17; i++)
retValue[i] = '\0';
sprintf(retValue, "Bytes: %02d-%s-%02d", rtc.date, rtc_get_month(&rtc), rtc.year);
Lcd_Write_String(1,1,retValue);
for(i=0; i< 17; i++)
retValue[i] = '\0';
sprintf(retValue," %02d:%02d:%02d", rtc.hour, rtc.min, rtc.sec);
Lcd_Write_String(2,1,retValue);
__delay_ms(1000);
}
return;
}