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comparison ds1307.c @ 0:3879f487b661

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Initial commit of routines I copy and paste. Need work to make them more portable (esp cons)
author darius@Inchoate
date Wed, 11 Mar 2009 16:42:27 +1030
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children 15d89caaf516
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-1:000000000000 0:3879f487b661
1 /*
2 * Interface to a DS1307
3 *
4 * Copyright (c) 2008
5 * Daniel O'Connor <darius@dons.net.au>. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <inttypes.h>
32 #include <avr/io.h>
33 #include <avr/pgmspace.h>
34 #include <util/twi.h>
35 #include <util/delay.h>
36
37 #include "ds1307.h"
38
39 // #define TWDEBUG
40
41 /*
42 * ds1307_init
43 *
44 * Setup TWI interface
45 *
46 */
47 int
48 ds1307_init(void) {
49 PRR &= _BV(PRTWI); /* Power TWI on - note that the
50 * datasheet says this is already 0 at
51 * power on.. */
52 TWSR = 0; /* TWI Prescaler = 1 */
53 #if F_CPU < 3600000UL
54 TWBR = 10; /* Smallest valid TWBR */
55 #else
56 TWBR = (F_CPU / 100000UL - 16) / 2;
57 #endif
58
59 TWCR = _BV(TWEN);
60
61 return(0);
62 }
63
64 /*
65 * iic_read
66 *
67 * Read len bytes of data from address adr in slave sla into
68 * data. Presume that the slave auto-increments the address on
69 * successive reads.
70 *
71 * Returns the number of bytes read, or the following on failure.
72 * IIC_STFAIL Could generate START condition (broken bus or busy).
73 * IIC_FAILARB Failed bus arbitration.
74 * IIC_SLNAK Slave NAK'd.
75 * IIC_NOREPLY No reply (no such slave?)
76 * IIC_UNKNOWN Unexpected return from TWI reg.
77 *
78 * Heaviy cribbed from twitest.c by Joerg Wunsch
79 */
80 int8_t
81 iic_read(uint8_t *data, uint8_t len, uint8_t adr, uint8_t sla) {
82 uint8_t twst, twcr, cnt;
83
84 /* Generate START */
85 TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);
86
87 /* Spin waiting for START to be generated */
88 while ((TWCR & _BV(TWINT)) == 0)
89 ;
90 switch (twst = TW_STATUS) {
91 case TW_REP_START: /* OK but shouldn't happen */
92 case TW_START:
93 break;
94
95 case TW_MT_ARB_LOST:
96 return IIC_FAILARB;
97 break;
98
99 default:
100 /* Not in start condition, bail */
101 return IIC_UNKNOWN;
102 }
103 #ifdef TWDEBUG
104 printf_P(PSTR("Sent START\r\n"));
105 #endif
106 /* Send SLA+W */
107 TWDR = sla | TW_WRITE;
108 TWCR = _BV(TWINT) | _BV(TWEN);
109
110 /* Spin waiting for a response to be generated */
111 while ((TWCR & _BV(TWINT)) == 0)
112 ;
113
114 #ifdef TWDEBUG
115 printf_P(PSTR("Sent SLA+W\r\n"));
116 #endif
117 switch (twst = TW_STATUS) {
118 case TW_MT_SLA_ACK:
119 break;
120
121 case TW_MT_SLA_NACK:
122 /* Send STOP */
123 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
124 return IIC_SLNAK;
125
126 case TW_MT_ARB_LOST:
127 return IIC_FAILARB;
128 break;
129
130 default:
131 /* Send STOP */
132 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
133 return IIC_UNKNOWN;
134 }
135 /* Send address */
136 TWDR = adr;
137 TWCR = _BV(TWINT) | _BV(TWEN);
138
139 /* Spin waiting for a response to be generated */
140 while ((TWCR & _BV(TWINT)) == 0)
141 ;
142 #ifdef TWDEBUG
143 printf_P(PSTR("Sent address\r\n"));
144 #endif
145 switch ((twst = TW_STATUS)) {
146 case TW_MT_DATA_ACK:
147 break;
148
149 case TW_MT_DATA_NACK:
150 /* Send STOP */
151 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
152 return IIC_SLNAK;
153
154 case TW_MT_ARB_LOST:
155 return IIC_FAILARB;
156
157 default:
158 /* Send STOP */
159 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
160 return IIC_UNKNOWN;
161 }
162
163 /* Master receive cycle */
164 TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);
165 while ((TWCR & _BV(TWINT)) == 0) /* wait for transmission */
166 ;
167
168 #ifdef TWDEBUG
169 printf_P(PSTR("Sent START\r\n"));
170 #endif
171 switch ((twst = TW_STATUS)) {
172 case TW_REP_START: /* OK but shouldn't happen */
173 case TW_START:
174 break;
175
176 case TW_MT_ARB_LOST:
177 return IIC_FAILARB;
178
179 default:
180 /* Send STOP */
181 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
182 return IIC_UNKNOWN;
183 }
184
185 /* send SLA+R */
186 TWDR = sla | TW_READ;
187 TWCR = _BV(TWINT) | _BV(TWEN); /* clear interrupt to start transmission */
188
189 /* Spin waiting for a response to be generated */
190 while ((TWCR & _BV(TWINT)) == 0)
191 ;
192 #ifdef TWDEBUG
193 printf_P(PSTR("Sent SLA+R\r\n"));
194 #endif
195 switch ((twst = TW_STATUS)) {
196 case TW_MR_SLA_ACK:
197 break;
198
199 case TW_MR_SLA_NACK:
200 /* Send STOP */
201 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
202 return IIC_SLNAK;
203
204 case TW_MR_ARB_LOST:
205 return IIC_FAILARB;
206
207 default:
208 /* Send STOP */
209 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
210 return IIC_UNKNOWN;
211 }
212
213 cnt = 0;
214 for (twcr = _BV(TWINT) | _BV(TWEN) | _BV(TWEA);
215 len > 0; len--) {
216 /* Send NAK on last byte */
217 if (len == 1)
218 twcr = _BV(TWINT) | _BV(TWEN);
219 TWCR = twcr; /* clear int to start transmission */
220 /* Spin waiting for a response to be generated */
221 while ((TWCR & _BV(TWINT)) == 0)
222 ;
223 #ifdef TWDEBUG
224 printf_P(PSTR("Data request done\r\n"));
225 #endif
226 switch ((twst = TW_STATUS)) {
227 case TW_MR_DATA_NACK:
228 /* Send STOP */
229 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
230 //printf_P(PSTR("NACK on byte %d\r\n"), cnt);
231 return cnt;
232
233 case TW_MR_DATA_ACK:
234 *data++ = TWDR;
235 //printf_P(PSTR("ACK on byte %d for 0x%02x\r\n"), cnt, *(data - 1));
236 cnt++;
237 break;
238
239 default:
240 return IIC_UNKNOWN;
241 }
242 }
243
244 /* Send STOP */
245 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
246 return cnt;
247 }
248
249 /*
250 * iic_write
251 *
252 * Write len bytes of data from address adr in slave sla into
253 * data. Presume that the slave auto-increments the address on
254 * successive writes.
255 *
256 * Returns the number of bytes read, or the following on failure.
257 * IIC_STFAIL Could generate START condition (broken bus or busy).
258 * IIC_FAILARB Failed bus arbitration.
259 * IIC_SLNAK Slave NAK'd.
260 * IIC_NOREPLY No reply (no such slave?)
261 * IIC_UNKNOWN Unexpected return from TWI reg.
262 *
263 * Heaviy cribbed from twitest.c by Joerg Wunsch
264 */
265 int8_t
266 iic_write(uint8_t *data, uint8_t len, uint8_t adr, uint8_t sla) {
267 uint8_t twst, cnt;
268
269 /* Generate START */
270 TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);
271
272 /* Spin waiting for START to be generated */
273 while ((TWCR & _BV(TWINT)) == 0)
274 ;
275 switch (twst = TW_STATUS) {
276 case TW_REP_START: /* OK but shouldn't happen */
277 case TW_START:
278 break;
279
280 case TW_MT_ARB_LOST:
281 return IIC_FAILARB;
282 break;
283
284 default:
285 /* Not in start condition, bail */
286 return IIC_UNKNOWN;
287 }
288 #ifdef TWDEBUG
289 printf_P(PSTR("Sent START\r\n"));
290 #endif
291
292 /* Send SLA+W */
293 TWDR = sla | TW_WRITE;
294 TWCR = _BV(TWINT) | _BV(TWEN);
295
296 /* Spin waiting for a response to be generated */
297 while ((TWCR & _BV(TWINT)) == 0)
298 ;
299
300 #ifdef TWDEBUG
301 printf_P(PSTR("Sent SLA+W\r\n"));
302 #endif
303 switch (twst = TW_STATUS) {
304 case TW_MT_SLA_ACK:
305 break;
306
307 case TW_MT_SLA_NACK:
308 /* Send STOP */
309 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
310 return IIC_SLNAK;
311
312 case TW_MT_ARB_LOST:
313 return IIC_FAILARB;
314 break;
315
316 default:
317 /* Send STOP */
318 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
319 return IIC_UNKNOWN;
320 }
321 /* Send address */
322 TWDR = adr;
323 TWCR = _BV(TWINT) | _BV(TWEN);
324
325 /* Spin waiting for a response to be generated */
326 while ((TWCR & _BV(TWINT)) == 0)
327 ;
328 #ifdef TWDEBUG
329 printf_P(PSTR("Sent address\r\n"));
330 #endif
331 switch ((twst = TW_STATUS)) {
332 case TW_MT_DATA_ACK:
333 break;
334
335 case TW_MT_DATA_NACK:
336 /* Send STOP */
337 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
338 return IIC_SLNAK;
339
340 case TW_MT_ARB_LOST:
341 return IIC_FAILARB;
342
343 default:
344 /* Send STOP */
345 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
346 return IIC_UNKNOWN;
347 }
348
349 cnt = 0;
350 for (; len > 0; len--) {
351 TWDR = *data++;
352 TWCR = _BV(TWINT) | _BV(TWEN);
353
354 /* Spin waiting for a response to be generated */
355 while ((TWCR & _BV(TWINT)) == 0)
356 ;
357 #ifdef TWDEBUG
358 printf_P(PSTR("Data sent\r\n"));
359 #endif
360 switch ((twst = TW_STATUS)) {
361 case TW_MT_DATA_NACK:
362 /* Send STOP */
363 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
364 return cnt;
365
366 case TW_MT_DATA_ACK:
367 cnt++;
368 break;
369
370 default:
371 return IIC_UNKNOWN;
372 }
373 }
374
375 /* Send STOP */
376 TWCR = _BV(TWINT) | _BV(TWSTO) | _BV(TWEN);
377 return cnt;
378 }
379
380 /*
381 * ds1307_gettod
382 *
383 * Read time of day from DS1307 into time
384 *
385 * Note that we canonify to 24hr mode.
386 *
387 */
388 int8_t
389 ds1307_gettod(ds1307raw_t *time) {
390 int8_t len;
391
392 len = iic_read((uint8_t *)time, sizeof(ds1307raw_t) + 1, 0, DS1307_ADR);
393 if (len < 0) {
394 printf_P(PSTR("iic_read failed - %d\r\n"), len);
395 return(0);
396 }
397
398 #if 1
399 if (len != sizeof(ds1307raw_t)) {
400 printf_P(PSTR("Only got %d bytes (vs %d)\r\n"), len, sizeof(ds1307raw_t));
401 return(0);
402 }
403 #endif
404
405 #ifdef TWDEBUG
406 int i;
407
408 for (i = 0; i < len; i++)
409 printf_P(PSTR("0x%02x: 0x%02x\r\n"), i, *(((uint8_t *)time) + i));
410 #endif
411
412 return(1);
413 }
414
415 /*
416 * ds1307_settod
417 *
418 * Set the DS1307 with the supplied time, format like so
419 * sc 2008/10/29 23:45:30
420 *
421 */
422 int8_t
423 ds1307_settod(char *date) {
424 ds1307raw_t rtime;
425 uint16_t year;
426 uint8_t i, month, day, hour, min, sec;
427
428 if ((i = sscanf_P(date, PSTR("%hu/%hhd/%hhd %hhd:%hhd:%hhd"), &year, &month, &day, &hour, &min, &sec)) != 6) {
429 printf_P(PSTR("Can't parse date\r\n"));
430 return(0);
431 }
432
433 if (year > 1900)
434 year -= 1900;
435
436 rtime.split.year10 = year / 10;
437 rtime.split.year = year % 10;
438 rtime.split.month10 = month / 10;
439 rtime.split.month = month % 10;
440 rtime.split.day10 = day / 10;
441 rtime.split.day = day % 10;
442 rtime.split.pmam = ((hour / 10) & 0x02) >> 1;
443 rtime.split.hour10 = (hour / 10) & 0x01;
444 rtime.split.hour = hour % 10;
445 rtime.split.min10 = min / 10;
446 rtime.split.min = min % 10;
447 rtime.split.sec10 = sec / 10;
448 rtime.split.sec = sec % 10;
449
450 rtime.split.ch = 0; // Enable clock
451 rtime.split.s1224 = 0; // 24 hour mode
452 rtime.split.dow = 0; // XXX: unused
453 rtime.split.out = 0; // No clock out
454
455 #ifdef TWDEBUG
456 for (i = 0; i < sizeof(ds1307raw_t); i++)
457 printf_P(PSTR("0x%02x: 0x%02x\r\n"), i, *(((uint8_t *)&rtime) + i));
458 #endif
459 if ((i = iic_write((uint8_t *)&rtime, sizeof(ds1307raw_t), 0, DS1307_ADR)) != sizeof(ds1307raw_t))
460 printf_P(PSTR("Can't write to RTC, sent %d (vs %d)\r\n"), i, sizeof(ds1307raw_t));
461
462 return(1);
463 }
464
465 /*
466 * ds1307_printtime
467 *
468 * Print the time in rtime with trailer
469 *
470 */
471 void
472 ds1307_printtime(char *leader, char *trailer) {
473 ds1307raw_t rtime;
474 uint8_t hour;
475
476 if (ds1307_gettod(&rtime) != 1)
477 return;
478
479 // Handle 12/24 hour time
480 hour = rtime.split.hour10 * 10 + rtime.split.hour;
481 if (rtime.split.s1224) {
482 if (rtime.split.pmam)
483 hour += 12;
484 } else
485 hour += (rtime.split.pmam << 1) * 10;
486
487 printf_P(PSTR("%S%04d/%02d/%02d %02d:%02d:%02d%S"), leader,
488 1900 + rtime.split.year10 * 10 + rtime.split.year,
489 rtime.split.month10 * 10 + rtime.split.month,
490 rtime.split.day10 * 10 + rtime.split.day,
491 hour,
492 rtime.split.min10 * 10 + rtime.split.min,
493 rtime.split.sec10 * 10 + rtime.split.sec,
494 trailer);
495 }