Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

problem interfacing ds1307 with pic16f877

Status
Not open for further replies.
R

ramxis

Newbie level 5
Joined
Sep 15, 2011
Messages
8
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,283
Activity points
1,424
hi. below is my code for interfacing ds1307 with pic16f877 i am using hi-tech with mplab .i am having an issue that i always get 00:00:00 on time and 00/00/2000 on date no matter what value i
initialize the time and date to. this code is part of my fyp and i have been strugling with it for quite a while now please read through and help me figure out what i am doing wrong . my suspicion is the i2c protocol i have used is not working.
COde......


Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447

#include<pic.h>
 
 
#define SCL TRISC3//RC3 
#define SDA TRISC4
 
//LCD functions
void delay(void);
void command(unsigned char com);
void display(unsigned char ascii);//for sending display information to lcd
void dip(void);
 
//I2c PRotocol for pic
void initialize(void);//put initial info on lcd
void I2CInit(void);//initialize I2c protocol
void Stop();
void Start();
void Restart();
void Ack();
void Nak();
void Wait();
void Send(unsigned char dat);
unsigned char Read(void);
 
/
unsigned char BCD2UpperCh(unsigned char bcd);
unsigned char BCD2LowerCh(unsigned char bcd);
 
//unsigned char init_info[12]={'D','a','t','e',':','8','/','2','7','/','1','1'};//,'0',':','3','5',' ','8','9','5','L'};
//unsigned char second_info[10]={'T','i','m','e',':','0','9',':','5','5'};
unsigned char intensity_info[13]={'i','n','t','e','n','s','i','t','y',':','8','5','9'};
unsigned char pr_info[12]={'P','r','e','v','i','o','u','s',':','8','2','0'};
 
unsigned short table[8];
unsigned short I2CData[8] = {0x00, 0x10, 0x01, 0x02, 0x05, 0x01, 0x09, 0x10};//14:27:00 17/6/2008
 
//unsigned short I2CData[8];// = {'0', '0', '0', '1', '1', '1', '9', '0'};
 
main()
{
 
    unsigned char test,i;
 
        unsigned char j;
 
 
//*************************************************************************
//*************************************************************************
//                              write
//*************************************************************************
//*************************************************************************
 
        // Initialize I2C Port
        I2CInit();
        
        //Send Start condition 
        Start();
        
        //Send DS1307 slave address with write operation 
        
        Send(0xD0);
        
        // Send subaddress 0x00, we are writing to this location 
        Send(0x00);
 
      
        
 //Loop to write 8 bytes 
//unsigned short address=0x00;
        for(j=0;j<8;j++) 
        {
                
                  // Send subaddress 0x00, we are writing to this location 
                //Send(address);
                // send I2C data one by one 
               Send(I2CData[j]);
                //address++;
        }
 
        //Send a stop condition - as transfer finishes 
        Stop();
        dip();  
 
//******************************************************************************
//**************************************read from ds1307************************
//******************************************************************************
//******************************************************************************
        //Reading for a memory based device always starts with a dummy write 
        // Send a start condition 
        Start();
 
        // Send slave address with write 
        Send(0xD0);
 
        // Send address for dummy write operation 
        //this address is actually where we are going to read from 
        Send(0x00);
 
        //Send a repeated start, after a dummy write to start reading 
        Restart();
        // send slave address with read bit set 
        Send(0xD1);
        // Loop to read 8 bytes from I2C slave 
        //int readaddress=0;
        for(i=8;i>0;i--) 
        {
                /* read a byte */
                //I2CData[i] = Read();
                // Send slave address with write 
               /* Send(0xD0);
        
               
                Send(0x00);
        
                
                Restart();
               
                Send(0xD1);*/
                table[i]=Read();
                //readaddress++;
                
                if(i-1) Ack(); // ACK if its not the last byte to read 
                else Nak();// if its the last byte then send a NAK 
        }
        /* Send stop */
        Stop();
        
    
//**********************************************************************    
//******************display calls***************************************
//**********************************************************************
//**********************************************************************
    initialize();
    for(i=0;i<2;i++)
    {
    for(test=0;test<200;test++)
    {
        delay();
    }
    }
    //dip();
 
 
 
 
 
 
 
 
 
 
    while(1)
    {
 
    }
    
 
 
    
 
}
/**************************************************************************
***************************************************************************
                            MAIN ends here
***************************************************************************
**************************************************************************/
 
 
//delay functions
void delay(void)//of roughly 5msec
{
        int i=0;
        for(i=0;i<=255;i++)
        {
        }   
}   
 
/**************************************************************************
***************************************************************************
                            LCD Functions
***************************************************************************
**************************************************************************/
void command(unsigned char com)
{
    delay();
    PORTD=com;
    RC0=0;
    RC1=0;
    RC2=1;
    RC2=0;
    
}   
 
void display(unsigned char ascii)
{
    delay();
    PORTD=ascii;
    RC0=1;
    RC1=0;
    RC2=1;
    delay();
    RC2=0;
}
 
void initialize(void)
{
    unsigned char i,j;
    TRISC0=0;
    TRISC1=0;
    TRISC2=0;
    TRISD=0;
// configure portd as output
    
    command(0x38);
    command(0x0f);
    command(0x01);
    command(0x80);
    command(0x06);
    
    
    //unsigned char i;
    /*for(i=0;i<12;i++)
    {
        
 
        display(init_info[i]);
        
    }*/
    
    /*  for(i=0;i<5;i++)
    {
        display(second_info[i]);
    }*/
    
    
    
    //Display time
        char time[9];
        time[0] = BCD2UpperCh(table[2]);//hours
        time[1] = BCD2LowerCh(table[2]);//hours
        time[2] = ':';
        time[3] = BCD2UpperCh(table[1]);
        time[4] = BCD2LowerCh(table[1]);//minutes
        time[5] = ':';
        time[6] = BCD2UpperCh(table[0]);
        time[7] = BCD2LowerCh(table[0]);//seconds
        time[8] = '\0';
    for(i=0;i<9;i++)
    {
        //display(second_info[i]);
        
        display(time[i]);
    }
    //display dow
    display(BCD2UpperCh(table[3]));
    display(BCD2LowerCh(table[3]));
 
    //Display date
    command(0xc0);
    command(0x06);
    for(j=0;j<11;j++)
    {
        char date[11];  
        date[0] = BCD2UpperCh(table[4]);
        date[1] = BCD2LowerCh(table[4]);//date
        date[2] ='/';
        date[3] = BCD2UpperCh(table[5]);
        date[4] = BCD2LowerCh(table[5]);//month
        date[5] ='/';
        date[6] = '2';
        date[7] = '0';
        date[8] = BCD2UpperCh(table[6]);
        date[9] = BCD2LowerCh(table[6]);//year
        date[10] = '\0';
        display(date[j]);
    }
 
 
 
}
 
void dip(void)
{
unsigned char i;
    TRISC0=0;
    TRISC1=0;
    TRISC2=0;
    TRISD=0;
    
    command(0x38);
    command(0x0F);
    command(0x01);
    command(0x80);
    command(0x06);
    
 
    //unsigned char i;
    for(i=0;i<13;i++)
    {
        display(intensity_info[i]);
    }
    
 
    //remove later
    command(0xc0);
    command(0x06);
    for(i=0;i<12;i++)
    {
    display(pr_info[i]);
    }
    
 
 
 
}
 
/**************************************************************************
***************************************************************************
                            I2C Functions
***************************************************************************
**************************************************************************/
 
 
//-------------------------------
// Intialize I2C
//-------------------------------
void I2CInit(void)
{
        SCL = 1;      /* SDA and SCL as input pin */
        SDA = 1;      /* these pins can be configured either i/p or o/p */
        SSPSTAT |= 0x80; /* Slew rate disabled | (is bit wise or)*/
        SSPCON = 0x28;   /* SSPEN = 1, I2C Master mode,  */
        SSPADD = 0x09;//=0x28   /* 100Khz @ 4Mhz Fosc ,clock = FOSC/(4 * (SSPADD + 1))*/
}
 
 
//------------------------------------
 //Send a start condition on I2C Bus
//------------------------------------
 
void Start()
{
        SEN = 1;         // Start condition enabled 
        while(SEN);      // automatically cleared by hardware 
                     // wait for start condition to finish 
}
 
//-----------------------------------
// Send a stop condition on I2C Bus
//------------------------------------
void Stop()
{
        PEN = 1;         /* Stop condition enabled */
        while(PEN);     
                     /* PEN automatically cleared by hardware */
}
 
//tells nopt to release the bus
void Restart()
{
        RSEN = 1;        /* Repeated start enabled */
        while(RSEN);     
}
 
/*
-------------------------------------------------
 
         Generates ACK
-------------------------------------------------
*/
void Ack()
{
        ACKDT = 0;       /* Acknowledge data bit, 0 = ACK */
        ACKEN = 1;       /* Ack data enabled */
        while(ACKEN);    /* wait for ack data to send on bus */
}
 
/*
-----------------------------------------------------
 Generates a Nack
-----------------------------------------------------
*/
void Nak()
{
        ACKDT = 1;       // Acknowledge data bit, 1 = NAK 
        ACKEN = 1;       // Ack data enabled 
        while(ACKEN);    // wait for ack data to send on bus 
}
 
/*
-----------------------------------------------------
                        wait 
-----------------------------------------------------
*/
void Wait()
{
        while ( ( SSPCON2 & 0x1F ) || ( SSPSTAT & 0x04 ) );
    // wait for any pending transfer 
}
 
/*
-----------------------------------------------------
                        Send
 
 
-----------------------------------------------------
*/
void Send(unsigned char dat)
{
        SSPBUF = dat;    // Move data to SSPBUF 
        TRISC6=ACKSTAT; //chechk if ack recieved from slave
        while(BF);       // wait till complete data is sent from buffer 
        //dip();
        Wait();       // wait for any pending transfer 
}
 
/*
-----------------------------------------------------
                    Read
 
-----------------------------------------------------
*/
unsigned char Read(void)
{
        unsigned char temp;
                        // Reception works if transfer is initiated in read mode 
        RCEN = 1;        // Enable data reception 
        while(!BF);      // wait for buffer full 
        temp = SSPBUF;   // Read serial buffer and store in temp register 
        Wait();       // wait to check any pending transfer 
        return temp;     // Return the read data from bus 
}
 
 
 
//--------------------------------------------------------
//  Chararcter conversion functions for displaying on lcd
//--------------------------------------------------------
unsigned char BCD2UpperCh(unsigned char bcd)
{
return ((bcd >> 4) + '0');
}
 
unsigned char BCD2LowerCh(unsigned char bcd)
{
return ((bcd & 0x0F) + '0');
}
 
Last edited by a moderator:

any one please help me in this matter if you can
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top