/***************************************************************************/
/* DEMO3231.C */
/***************************************************************************/
#include <stdio.h> /* Prototypes for I/O functions */
#include <DS5000.h> /* Register declarations for DS5000 */
/************************* bit definitions ****************************/
sbit scl = P0^0; /* I2C pin definitions */
sbit sda = P0^1;
sbit E = P1^0; /* DCM LCD module control signal definitions */
sbit RS = P1^1;
sbit RW = P1^2;
sbit CLK = P2^5; /* DS1267 control signal definitions */
sbit RSTb = P2^6;
sbit DQ = P2^7;
sbit int0 = P3^2;
/**************************** defines *******************************/
#define ADDRTC 0xd0 /* DS3231 slave address (write) */
#define ACK 0
#define NACK 1
/*********************** Function Prototypes **************************/
void start();
void stop();
uchar i2cwrite(uchar d);
uchar i2cread(char);
void wr_dsp_dat(uchar);
void wr_dsp_ins(uchar);
uchar rd_dsp_ins();
void hex2asc(uchar);
void dsp_adj(uchar pos);
void init_dsp();
void writebyte();
void initialize_DS3231();
void disp_regs();
void rd_temp();
void frq_out_tog();
void init_alrm();
void comm_init();
/************************* Global Variables ***************************/
xdata uchar sec, min, hr, dy, dt, mn, yr;
/**************************** functions ******************************/
void start() /* --------- Initiate start condition ---------- */
{
sda = 1; scl = 1;
sda = 0;
}
void stop() /* ---------- Initiate stop condition ----------- */
{
sda = 0; sda = 0;
scl = 1; scl = 1; sda = 1;
}
uchar i2cwrite(uchar d) /* ----------------------------- */
{
uchar i;
scl = 0;
for (i = 0;i < 8; i++)
{
if (d & 0x80)
sda = 1; /* Send the msbits first */
else
sda = 0;
scl = 0;
scl = 1;
d = d << 1; /* do shift here to increase scl high time */
scl = 0;
}
sda = 1; /* Release the sda line */
scl = 0;
scl = 1;
i = sda;
if (i) printf("Ack bit missing %02X\n",(unsigned int)d);
scl = 0;
return(i);
}
uchar i2cread(char b) /* ----------------------------------- */
{
uchar i, d;
d = 0;
sda = 1; /* Let go of sda line */
scl = 0;
for (i = 0; i < 8; i++) /* read the msb first */
{
scl = 1;
d = d << 1;
d = d | (unsigned char)sda;
scl = 0;
}
sda = b; /* low for ack, high for nack */
scl = 1;
scl = 0;
sda = 1; /* Release the sda line */
return d;
}
void wr_dsp_dat(uchar dat) /* -------- write one byte to the display --------- */
{
P0 = dat;
RS = 1; /* data register */
RW = 0; /* write */
E = 1;
E = 0; /* latch data in */
}
void wr_dsp_ins(uchar dat) /* ---- write one byte to the display instruction ----- */
{
P0 = dat;
RS = 0; /* instruction register */
RW = 0; /* write */
E = 1;
E = 0; /* latch data in */
}
uchar rd_dsp_ins() /* ---- read one byte from the instruction registers ----- */
{
uchar dat;
P0 = 0xff; /* set up for read */
RS = 0; /* instruction register */
RW = 1; /* read */
E = 1;
dat = P0;
E = 0;
return(dat);
}
void init_dsp() /* -------- initialize DMC-16207 LCD display ------- */
{
while((rd_dsp_ins() & 0x80)); /* wait for display */
wr_dsp_ins(0x38); /* Set 8-bit data, 2-line display, 5X7 font */
while((rd_dsp_ins() & 0x80));
wr_dsp_ins(0x0c); /* Display on, cursor off, blink off */
while((rd_dsp_ins() & 0x80));
wr_dsp_ins(0x06); /* Entry mode set: increment, no display shift */
while((rd_dsp_ins() & 0x80));
wr_dsp_ins(0x01); /* clear display */
while((rd_dsp_ins() & 0x80));
wr_dsp_ins(0x80); /* move to start of line 1 */
while((rd_dsp_ins() & 0x80));
wr_dsp_ins(0x50); /* Set CG RAM address */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x07); /* write 1st line of custom char to CG RAM */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x05); /* write 2nd line */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x07); /* write 3rd line */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x00); /* write 4th line */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x00); /* write 5th line */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x00); /* write 6th line */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x00); /* write 7th line */
while((rd_dsp_ins() & 0x80));
}
void hex2asc(uchar hex) /* -- convert the upper and lower nibbles to 2 ascii characters -- */
{
if( ( (hex & 0xf0) >> 4) < 0x0a)
wr_dsp_dat( ( (hex & 0xf0) >> 4) + 48 ); /* prints 0-9 */
else
wr_dsp_dat( ( (hex & 0xf0) >> 4) + 55 ); /* prints A-F */
while((rd_dsp_ins() & 0x80));
if( (hex & 0x0f) < 0x0a)
wr_dsp_dat( (hex & 0x0f) + 48 );
else
wr_dsp_dat( (hex & 0x0f) + 55 );
while((rd_dsp_ins() & 0x80));
}
void dsp_adj(uchar pos) /* ------ adjust contrast on LCD display ------- */
{
char inc;
RSTb = CLK = 0; /* initialize for 1st pass */
RSTb = 1; /* enable DS1267 */
DQ = 0; /* write stack select bit */
CLK = 1; /* toggle clk with data valid */
CLK = 0;
for (inc = 7; inc >= 0; inc--) /* write wiper 0 */
{
DQ = ((pos >> inc) & 0x01); /* shift x bits left */
CLK = 0; /* toggle clk with data valid */
CLK = 1;
}
for (inc = 7; inc >= 0; inc--) /* write wiper 1 */
{
DQ = ((pos >> inc) & 0x01); /* shift x bits left */
CLK = 0; /* toggle clk with data valid */
CLK = 1;
}
RSTb = 0; /* reset the 1267 (/RST & CLK low) */
CLK = 0;
}
void writebyte() /* ----------------------------------------------- */
{
uchar Add, Data;
printf("\nADDRESS (hex):"); /* Get Address & Data */
scanf("%bx", &Add);
printf("DATA (hex):");
scanf("%bx", &Data);
start();
i2cwrite(ADDRTC);
i2cwrite(Add);
i2cwrite(Data);
stop();
}
void initialize_DS3231() /* ----- set time & date; user data entry ------ */
/* Note: NO error checking is done on the user entries! */
{
printf("\nEnter the year (0-99): ");
scanf("%bx", &yr);
printf("Enter the month (1-12): ");
scanf("%bx", &mn);
printf("Enter the date (1-31): ");
scanf("%bx", &dt);
printf("Enter the day (1-7): ");
scanf("%bx", &dy);
printf("Enter the hour (1-23): ");
scanf("%bx", &hr);
/* hr = hr & 0x3f; /* force clock to 24 hour mode */
printf("Enter the minute (0-59): ");
scanf("%bx", &min);
printf("Enter the second (0-59): ");
scanf("%bx", &sec);
start();
i2cwrite(ADDRTC); /* write slave address, write 1339 */
i2cwrite(0x00); /* write register address, 1st clock register */
i2cwrite(sec);
i2cwrite(min);
i2cwrite(hr);
i2cwrite(dy);
i2cwrite(dt);
i2cwrite(mn);
i2cwrite(yr);
i2cwrite(0x10); /* enable sqw, 1hz output */
stop();
}
void disp_regs() /* --- display date/time on LCD display --- */
{
uchar age, prv_sec=99;
while(!RI) /* Read & Display Clock Registers */
{
while(int0); /* loop until int pin goes low */
start();
i2cwrite(ADDRTC);
i2cwrite(0x0f);
i2cwrite(0); /* clear alarm flags */
stop();
start();
i2cwrite(ADDRTC);
i2cwrite(0);
start();
i2cwrite(ADDRTC | 1);
sec = i2cread(ACK);
min = i2cread(ACK);
hr = i2cread(ACK);
dy = i2cread(ACK);
dt = i2cread(ACK);
mn = i2cread(ACK);
yr = i2cread(NACK);
stop();
wr_dsp_ins(0x80); /* move to start of line 1 */
while((rd_dsp_ins() & 0x80));
hex2asc(yr);
wr_dsp_dat('/');
while((rd_dsp_ins() & 0x80));
hex2asc(mn);
wr_dsp_dat('/');
while((rd_dsp_ins() & 0x80));
hex2asc(dt);
wr_dsp_dat(' ');
while((rd_dsp_ins() & 0x80));
hex2asc(dy);
wr_dsp_dat(' ');
while((rd_dsp_ins() & 0x80));
start();
i2cwrite(ADDRTC);
i2cwrite(0x10);
start();
i2cwrite(ADDRTC | 1);
age = i2cread(NACK);
stop();
wr_dsp_dat(' ');
while((rd_dsp_ins() & 0x80));
hex2asc(age);
wr_dsp_ins(0xc0); /* move to start of line 2 */
while((rd_dsp_ins() & 0x80));
hex2asc(hr);
wr_dsp_dat(':');
while((rd_dsp_ins() & 0x80));
hex2asc(min);
wr_dsp_dat(':');
while((rd_dsp_ins() & 0x80));
hex2asc(sec);
rd_temp();
}
RI = 0; /* Swallow keypress to exit loop */
}
void rd_temp() /* -------- display temperature -------- */
{
char str[8];
int itemp;
float ftemp;
do
{
start();
i2cwrite(ADDRTC);
i2cwrite(0x0e); /* address of control register */
start();
i2cwrite(ADDRTC + 1); /* send the device address for read */
itemp = i2cread(NACK); /* get the control register value */
stop();
} while(itemp & 0x20); /* wait until CNVT bit goes inactive */
start();
i2cwrite(ADDRTC);
i2cwrite(0x11); /* address of temperature MSB */
start();
i2cwrite(ADDRTC + 1); /* send the device address for read */
itemp = ( (int) i2cread(ACK) << 5 );
itemp += ( i2cread(NACK) >> 3);
stop();
if(itemp & 0x1000) itemp += 0xe000; /* if sign bit set, make 16 bit 2's comp */
ftemp = 0.03125 * (float) itemp; /* convert to degrees C */
/* ftemp = ftemp * 9 / 5 + 32; /* skip this if you don't want degrees F */
sprintf(str, "%5.2f", ftemp);
wr_dsp_ins(0xc9); /* go to line 2, column 10 */
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(str[0]);
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(str[1]);
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(str[2]);
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(str[3]);
while((rd_dsp_ins() & 0x80));
wr_dsp_dat(0x02); /* display programed 3rd char in CG RAM */
while((rd_dsp_ins() & 0x80));
}
void frq_out_tog() /* --- toggle en32khz bit to enable/disable sqw --- */
{
uchar val;
start();
i2cwrite(ADDRTC);
i2cwrite(0x0f); /* control/status reg address */
start();
i2cwrite(ADDRTC + 1); /* send the device address for read */
val = i2cread(NACK);
stop();
val ^= 0x08; /* toggle en32khz bit */
start();
i2cwrite(ADDRTC);
i2cwrite(0x0f); /* control/status reg address */
i2cwrite(val);
stop();
}
void init_alrm() /* --- enable alarm 1 for once-per-second --- */
{
start();
i2cwrite(ADDRTC);
i2cwrite(7); /* 1st alarm 1 reg address */
i2cwrite(0x80); /* mask alarm register */
i2cwrite(0x80);
i2cwrite(0x80);
i2cwrite(0x80);
stop();
start();
i2cwrite(ADDRTC);
i2cwrite(0x0e); /* control/status reg address */
i2cwrite(0x05); /* enable interrupts, alarm 1 output */
}
void comm_init() /* ------ reset DS3231 comm interface ------ */
{
do /* because the DS3231 I2C interface is active for both supplies */
{ /* after a micro reset, we must get the comm into a known state */
sda = 1; /* make sure master has released SDA */
scl = 1;
if(sda) /* if sda is high, generate a start */
{
sda = 0; /* The DS3231 will recognize a valid start */
sda = 1; /* condition anywhere in a I2C data transfer */
}
scl = 0;
} while(sda == 0); /* if the DS3231 is holding sda low, try again */
}
void main (void) /* ------------------------------------------------ */
{
uchar i, M, M1;
dsp_adj(0x10); /* adjust contrast on LCD display */
init_dsp(); /* initialize LCD display */
comm_init();
init_alrm(); /* enable alarm */
disp_regs();
while(1)
{
printf("\nDS3231 build date: %s\n", __DATE__);
printf("I Init DS3231 S Show temp\n");
printf("R Read Time W Write Byte\n");
printf("F Frq out D Display adj\n");
printf("Enter Menu Selection: ");
M = _getkey();
switch(M)
{
case 'D':
case 'd': printf("val: "); scanf("%bx", &M1);
dsp_adj(M1); break;
case 'F':
case 'f': frq_out_tog(); break;
case 'I':
case 'i': initialize_DS3231(); break;
case 'R':
case 'r': disp_regs(); break;
case 'S':
case 's': rd_temp(); break;
case 'W':
case 'w': writebyte(); break;
}
}
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