Mercurial > ~darius > hgwebdir.cgi > avr
annotate 1wire.c @ 50:a13e0ccc1d2d
Rejig how temperatures are logged. Print out the final line at the end so it
is printed in one hit.
| author | darius@Inchoate |
|---|---|
| date | Wed, 29 Oct 2008 16:06:42 +1030 |
| parents | efd44dc40934 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Various 1 wire routines | |
| 12 | 3 * Search routine is copied from the Dallas owpd library with mods |
| 4 * available from here http://www.ibutton.com/software/1wire/wirekit.html | |
| 0 | 5 * |
|
8
f9a085a0ba93
Change the 1 wire routines to mostly C with assembly delay routines
darius
parents:
0
diff
changeset
|
6 * $Id$ |
|
f9a085a0ba93
Change the 1 wire routines to mostly C with assembly delay routines
darius
parents:
0
diff
changeset
|
7 * |
| 0 | 8 * Copyright (c) 2004 |
| 9 * Daniel O'Connor <darius@dons.net.au>. All rights reserved. | |
| 10 * | |
| 11 * Redistribution and use in source and binary forms, with or without | |
| 12 * modification, are permitted provided that the following conditions | |
| 13 * are met: | |
| 14 * 1. Redistributions of source code must retain the above copyright | |
| 15 * notice, this list of conditions and the following disclaimer. | |
| 16 * 2. Redistributions in binary form must reproduce the above copyright | |
| 17 * notice, this list of conditions and the following disclaimer in the | |
| 18 * documentation and/or other materials provided with the distribution. | |
| 19 * | |
| 20 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
| 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 23 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE | |
| 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 30 * SUCH DAMAGE. | |
| 31 */ | |
| 32 | |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
33 /* |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
34 * No user servicable parts inside |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
35 * |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
36 * Modify 1wire-config.h |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
37 */ |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
38 |
| 0 | 39 #include <stdio.h> |
| 40 #include <avr/io.h> | |
| 41 #include <avr/pgmspace.h> | |
| 21 | 42 #include <util/delay.h> |
| 0 | 43 #include "1wire.h" |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
44 #include "1wire-config.h" |
| 41 | 45 #include "cons.h" |
| 0 | 46 |
| 47 static uint8_t OW_LastDevice = 0; | |
| 48 static uint8_t OW_LastDiscrepancy = 0; | |
| 49 static uint8_t OW_LastFamilyDiscrepancy = 0; | |
| 50 | |
|
45
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
51 const PROGMEM char *OWProgROM_Status[] = { |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
52 "OK", |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
53 "not possible (no HW support)", |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
54 "Invalid parameters", |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
55 "module doesn't exist or didn't respond properly" |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
56 }; |
|
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
57 |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
58 /*----------------------------------------------------------------------------- |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
59 * Configure the IO port as we need |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
60 */ |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
61 void |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
62 OWInit(void) { |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
63 OWBUSINIT(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
64 OWSETBUSHIGH(); |
| 0 | 65 } |
| 66 | |
| 67 /*----------------------------------------------------------------------------- | |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
68 * Generate a 1-Wire reset, return 0 if presence pulse was found, 1 if it |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
69 * wasn't, or 2 if the line appears to be being held low. |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
70 * |
| 0 | 71 * (NOTE: Does not handle alarm presence from DS2404/DS1994) |
| 72 */ | |
| 12 | 73 uint8_t |
| 0 | 74 OWTouchReset(void) { |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
75 OWDELAY_G; |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
76 |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
77 /* Check the bus isn't being held low (ie it's broken) Do it after |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
78 * the delay so we guarantee we don't see a slave from a previous |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
79 * comms attempt |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
80 */ |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
81 if(OWREADBUS() == 0) |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
82 return 2; |
| 0 | 83 |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
84 OWSETBUSLOW(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
85 OWDELAY_H; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
86 OWSETBUSHIGH(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
87 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
88 |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
89 return(OWREADBUS()); |
| 0 | 90 } |
| 91 | |
| 92 /*----------------------------------------------------------------------------- | |
| 93 * Send a 1-wire write bit. | |
| 94 */ | |
| 95 void | |
| 12 | 96 OWWriteBit(uint8_t bit) { |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
97 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
98 |
| 0 | 99 if (bit) { |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
100 OWSETBUSLOW(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
101 OWDELAY_A; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
102 OWSETBUSHIGH(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
103 OWDELAY_B; |
| 0 | 104 } else { |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
105 OWSETBUSLOW(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
106 OWDELAY_C; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
107 OWSETBUSHIGH(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
108 OWDELAY_D; |
| 0 | 109 } |
| 110 } | |
| 111 | |
| 112 /*----------------------------------------------------------------------------- | |
| 113 * Read a bit from the 1-wire bus and return it. | |
| 114 */ | |
| 12 | 115 uint8_t |
| 0 | 116 OWReadBit(void) { |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
117 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
118 |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
119 OWSETBUSLOW(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
120 OWDELAY_A; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
121 OWSETBUSHIGH(); |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
122 OWDELAY_E; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
123 return(OWREADBUS()); |
| 0 | 124 } |
| 125 | |
| 126 /*----------------------------------------------------------------------------- | |
| 127 * Write a byte to the 1-wire bus | |
| 128 */ | |
| 129 void | |
| 130 OWWriteByte(uint8_t data) { | |
| 12 | 131 uint8_t i; |
| 0 | 132 |
| 133 /* Send LSB first */ | |
| 134 for (i = 0; i < 8; i++) { | |
| 135 OWWriteBit(data & 0x01); | |
| 136 data >>= 1; | |
| 137 } | |
| 138 } | |
| 139 | |
| 140 /*----------------------------------------------------------------------------- | |
| 141 * Read a byte from the 1-wire bus | |
| 142 */ | |
| 12 | 143 uint8_t |
| 0 | 144 OWReadByte(void) { |
| 145 int i, result = 0; | |
| 146 | |
| 147 for (i = 0; i < 8; i++) { | |
| 148 result >>= 1; | |
| 149 if (OWReadBit()) | |
| 150 result |= 0x80; | |
| 151 } | |
| 152 return(result); | |
| 153 } | |
| 154 | |
| 155 /*----------------------------------------------------------------------------- | |
| 156 * Write a 1-wire data byte and return the sampled result. | |
| 157 */ | |
| 12 | 158 uint8_t |
| 0 | 159 OWTouchByte(uint8_t data) { |
| 12 | 160 uint8_t i, result = 0; |
| 0 | 161 |
| 162 for (i = 0; i < 8; i++) { | |
| 163 result >>= 1; | |
| 164 | |
| 165 /* If sending a 1 then read a bit, otherwise write a 0 */ | |
| 166 if (data & 0x01) { | |
| 167 if (OWReadBit()) | |
| 168 result |= 0x80; | |
| 169 } else | |
| 170 OWWriteBit(0); | |
| 171 | |
| 172 data >>= 1; | |
| 173 } | |
| 174 | |
| 175 return(result); | |
| 176 } | |
| 177 | |
| 178 /*----------------------------------------------------------------------------- | |
| 179 * Write a block of bytes to the 1-wire bus and return the sampled result in | |
| 180 * the same buffer | |
| 181 */ | |
| 182 void | |
| 183 OWBlock(uint8_t *data, int len) { | |
| 184 int i; | |
| 185 | |
| 186 for (i = 0; i < len; i++) | |
| 187 data[i] = OWTouchByte(data[i]); | |
| 188 } | |
| 189 | |
| 190 | |
| 191 /*----------------------------------------------------------------------------- | |
| 192 * Send a 1 wire command to a device, or all if no ROM ID provided | |
| 193 */ | |
| 194 void | |
| 195 OWSendCmd(uint8_t *ROM, uint8_t cmd) { | |
| 12 | 196 uint8_t i; |
| 0 | 197 |
| 198 OWTouchReset(); | |
| 199 | |
| 200 if (ROM == NULL) | |
| 201 OWWriteByte(OW_SKIP_ROM_CMD); | |
| 202 else { | |
| 203 OWWriteByte(OW_MATCH_ROM_CMD); | |
| 204 for (i = 0; i < 8; i++) | |
| 205 OWWriteByte(ROM[i]); | |
| 206 } | |
| 207 OWWriteByte(cmd); | |
| 208 } | |
| 209 | |
| 210 /*----------------------------------------------------------------------------- | |
| 211 * Search algorithm from App note 187 (and 162) | |
| 212 * | |
| 10 | 213 * OWFirst/OWNext return.. |
| 214 * 1 when something is found, | |
| 215 * 0 no more modules | |
| 16 | 216 * -1 if no presence pulse, |
| 10 | 217 * -2 if bad CRC, |
| 218 * -3 if bad wiring. | |
| 0 | 219 */ |
| 12 | 220 uint8_t |
| 0 | 221 OWFirst(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) { |
| 222 /* Reset state */ | |
| 223 OW_LastDiscrepancy = 0; | |
| 224 OW_LastDevice = 0; | |
| 225 OW_LastFamilyDiscrepancy = 0; | |
| 226 | |
| 227 /* Go looking */ | |
| 228 return (OWNext(ROM, do_reset, alarm_only)); | |
| 229 } | |
| 230 | |
| 231 /* Returns 1 when something is found, 0 if nothing left */ | |
| 12 | 232 uint8_t |
| 0 | 233 OWNext(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) { |
| 234 uint8_t bit_test, search_direction, bit_number; | |
| 10 | 235 uint8_t last_zero, rom_byte_number, rom_byte_mask; |
| 0 | 236 uint8_t lastcrc8, crcaccum; |
| 12 | 237 int8_t next_result; |
| 0 | 238 |
| 239 /* Init for search */ | |
| 21 | 240 bit_number = 1; |
| 241 last_zero = 0; | |
| 242 rom_byte_number = 0; | |
| 243 rom_byte_mask = 1; | |
| 244 next_result = OW_NOMODULES; | |
| 245 lastcrc8 = 0; | |
| 246 crcaccum = 0; | |
| 0 | 247 |
| 21 | 248 /* if the last call was not the last one */ |
| 249 if (!OW_LastDevice) { | |
| 250 /* check if reset first is requested */ | |
| 251 if (do_reset) { | |
| 252 /* reset the 1-wire | |
| 253 * if there are no parts on 1-wire, return 0 */ | |
| 41 | 254 OWPUTSP(PSTR("Resetting\r\n")); |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
255 switch (OWTouchReset()) { |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
256 case 0: |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
257 break; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
258 |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
259 case 1: |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
260 /* reset the search */ |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
261 OW_LastDiscrepancy = 0; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
262 OW_LastFamilyDiscrepancy = 0; |
| 41 | 263 OWPUTSP(PSTR("No devices on bus\r\n")); |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
264 return OW_NOPRESENCE; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
265 break; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
266 |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
267 case 2: |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
268 /* reset the search */ |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
269 OW_LastDiscrepancy = 0; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
270 OW_LastFamilyDiscrepancy = 0; |
| 41 | 271 OWPUTSP(PSTR("Bus appears to be being held low\r\n")); |
|
22
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
272 return OW_BADWIRE; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
273 break; |
|
bd792ebf813d
Report the bus being held low back to the caller from OWFirst/Next.
darius
parents:
21
diff
changeset
|
274 |
| 21 | 275 } |
| 276 } | |
| 0 | 277 |
| 21 | 278 /* If finding alarming devices issue a different command */ |
| 279 if (alarm_only) | |
| 280 OWWriteByte(OW_SEARCH_ALRM_CMD); /* issue the alarming search command */ | |
| 281 else | |
| 282 OWWriteByte(OW_SEARCH_ROM_CMD); /* issue the search command */ | |
| 0 | 283 |
| 21 | 284 /* pause before beginning the search */ |
|
32
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
285 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
286 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
287 OWDELAY_I; |
|
b0cb873c0206
Isolate the bus frobbing parts and the delays into a separate header.
darius
parents:
29
diff
changeset
|
288 |
| 21 | 289 /* loop to do the search */ |
| 290 do { | |
| 291 /* read a bit and its compliment */ | |
| 292 bit_test = OWReadBit() << 1; | |
| 293 bit_test |= OWReadBit(); | |
| 0 | 294 |
| 41 | 295 OWPRINTFP(PSTR("bit_test = %d\r\n"), bit_test); |
| 0 | 296 |
| 21 | 297 /* check for no devices on 1-wire */ |
| 298 if (bit_test == 3) { | |
| 41 | 299 OWPRINTFP(PSTR("bit_test = %d\r\n"), bit_test); |
| 21 | 300 return(OW_BADWIRE); |
| 301 } | |
| 302 else { | |
| 303 /* all devices coupled have 0 or 1 */ | |
| 304 if (bit_test > 0) | |
| 305 search_direction = !(bit_test & 0x01); /* bit write value for search */ | |
| 306 else { | |
| 307 /* if this discrepancy is before the Last Discrepancy | |
| 308 * on a previous OWNext then pick the same as last time */ | |
| 309 if (bit_number < OW_LastDiscrepancy) | |
| 310 search_direction = ((ROM[rom_byte_number] & rom_byte_mask) > 0); | |
| 311 else | |
| 312 /* if equal to last pick 1, if not then pick 0 */ | |
| 313 search_direction = (bit_number == OW_LastDiscrepancy); | |
| 0 | 314 |
| 21 | 315 /* if 0 was picked then record its position in LastZero */ |
| 316 if (search_direction == 0) { | |
| 317 last_zero = bit_number; | |
| 0 | 318 |
| 21 | 319 /* check for Last discrepancy in family */ |
| 320 if (last_zero < 9) | |
| 321 OW_LastFamilyDiscrepancy = last_zero; | |
| 322 } | |
| 323 } | |
| 0 | 324 |
| 21 | 325 /* set or clear the bit in the ROM byte rom_byte_number |
| 326 * with mask rom_byte_mask */ | |
| 327 if (search_direction == 1) | |
| 328 ROM[rom_byte_number] |= rom_byte_mask; | |
| 329 else | |
| 330 ROM[rom_byte_number] &= ~rom_byte_mask; | |
| 0 | 331 |
| 21 | 332 /* serial number search direction write bit */ |
| 333 OWWriteBit(search_direction); | |
| 0 | 334 |
| 21 | 335 /* increment the byte counter bit_number |
| 336 * and shift the mask rom_byte_mask */ | |
| 337 bit_number++; | |
| 338 rom_byte_mask <<= 1; | |
| 0 | 339 |
| 21 | 340 /* if the mask is 0 then go to new ROM byte rom_byte_number |
| 341 * and reset mask */ | |
| 342 if (rom_byte_mask == 0) { | |
| 343 OWCRC(ROM[rom_byte_number], &crcaccum); /* accumulate the CRC */ | |
| 344 lastcrc8 = crcaccum; | |
| 0 | 345 |
| 21 | 346 rom_byte_number++; |
| 347 rom_byte_mask = 1; | |
| 348 } | |
| 349 } | |
| 350 } while (rom_byte_number < 8); /* loop until through all ROM bytes 0-7 */ | |
| 0 | 351 |
| 21 | 352 /* if the search was successful then */ |
| 353 if (!(bit_number < 65) || lastcrc8) { | |
| 354 if (lastcrc8) { | |
| 41 | 355 OWPRINTFP(PSTR("Bad CRC (%d)\r\n"), lastcrc8); |
| 21 | 356 next_result = OW_BADCRC; |
| 357 } else { | |
| 358 /* search successful so set LastDiscrepancy,LastDevice,next_result */ | |
| 359 OW_LastDiscrepancy = last_zero; | |
| 360 OW_LastDevice = (OW_LastDiscrepancy == 0); | |
| 41 | 361 OWPRINTFP(PSTR("Last device = %d\r\n"), OW_LastDevice); |
| 21 | 362 next_result = OW_FOUND; |
| 363 } | |
| 364 } | |
| 365 } | |
| 0 | 366 |
| 21 | 367 /* if no device found then reset counters so next 'next' will be |
| 368 * like a first */ | |
| 369 if (next_result != OW_FOUND || ROM[0] == 0) { | |
| 370 OW_LastDiscrepancy = 0; | |
| 371 OW_LastDevice = 0; | |
| 372 OW_LastFamilyDiscrepancy = 0; | |
| 373 } | |
| 0 | 374 |
| 21 | 375 if (next_result == OW_FOUND && ROM[0] == 0x00) |
| 376 next_result = OW_BADWIRE; | |
| 10 | 377 |
| 21 | 378 return next_result; |
| 0 | 379 |
| 380 } | |
| 381 | |
| 382 uint8_t PROGMEM dscrc_table[] = { | |
| 383 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, | |
| 384 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, | |
| 385 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, | |
| 386 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, | |
| 387 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, | |
| 388 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, | |
| 389 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, | |
| 390 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, | |
| 391 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205, | |
| 392 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80, | |
| 393 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238, | |
| 394 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, | |
| 395 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, | |
| 396 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, | |
| 397 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, | |
| 398 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 | |
| 399 }; | |
| 400 | |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
401 /*----------------------------------------------------------------------------- |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
402 * Update *crc based on the value of x |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
403 */ |
| 0 | 404 void |
| 405 OWCRC(uint8_t x, uint8_t *crc) { | |
| 406 *crc = pgm_read_byte(&dscrc_table[(*crc) ^ x]); | |
| 407 } | |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
408 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
409 /*----------------------------------------------------------------------------- |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
410 * Program a DS2502's memory |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
411 * |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
412 * Arguments |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
413 * ROM - ROM ID (or NULL to send SKIP_ROM) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
414 * start - Start address (bytes) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
415 * len - Length of data to write |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
416 * data - Data to write |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
417 * exact - If true, only accept exact matches for programming, |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
418 * otherwise only ensure the bits we requested were |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
419 * programmed [to 0] |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
420 * status - If true program status rather than memory |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
421 * |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
422 * Returns.. |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
423 * 0 if all is OK |
|
45
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
424 * 1 if the programming is not possible |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
425 * 2 if the parameters were invalid |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
426 * 3 if the DS2502 didn't respond appropriately (also happens if the |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
427 * module doesn't exist) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
428 */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
429 uint8_t |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
430 OWProgROM(uint8_t *ROM, uint8_t start, uint8_t len, uint8_t *data, uint8_t exact, uint8_t status) { |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
431 #if defined(OWSETVPPON) && defined(OWSETVPPOFF) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
432 uint8_t crc, i, tmp; |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
433 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
434 /* Stupid programmer detection */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
435 if (status) { |
|
45
efd44dc40934
Add macros for number system used for temperatures.
darius@Inchoate
parents:
41
diff
changeset
|
436 if (start + len > 3) |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
437 return(2); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
438 } else { |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
439 if (start + len > 127) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
440 return(2); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
441 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
442 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
443 if (len < 1) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
444 return(2); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
445 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
446 OWDELAY_I; |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
447 if (OWTouchReset() != 0) { |
| 41 | 448 cons_putsP(PSTR("No presence pulse\r\n")); |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
449 return(3); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
450 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
451 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
452 crc = 0; |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
453 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
454 /* Send the command */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
455 if (status) { |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
456 OWSendCmd(ROM, OW_WRITE_STATUS); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
457 OWCRC(OW_WRITE_STATUS, &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
458 } else { |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
459 OWSendCmd(ROM, OW_WRITE_MEMORY); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
460 OWCRC(OW_WRITE_MEMORY, &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
461 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
462 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
463 /* And the start address |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
464 * (2 bytes even though one would do) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
465 */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
466 OWWriteByte(start); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
467 OWCRC(start, &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
468 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
469 OWWriteByte(0x00); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
470 OWCRC(0x00, &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
471 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
472 for (i = 0; i < len; i++) { |
| 41 | 473 cons_putsP(PSTR("Programming ")); |
| 474 cons_puts_hex(data[i]); | |
| 475 cons_putsP(PSTR(" to ")); | |
| 476 cons_puts_hex(start + i); | |
| 477 cons_putsP(PSTR("\r\n")); | |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
478 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
479 OWWriteByte(data[i]); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
480 OWCRC(data[i], &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
481 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
482 tmp = OWReadByte(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
483 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
484 if (crc != tmp) { |
| 41 | 485 cons_putsP(PSTR("CRC mismatch ")); |
| 486 cons_puts_hex(crc); | |
| 487 cons_putsP(PSTR(" vs ")); | |
| 488 cons_puts_hex(tmp); | |
| 489 cons_putsP(PSTR("\r\n")); | |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
490 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
491 OWTouchReset(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
492 return(3); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
493 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
494 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
495 OWSETVPPON(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
496 OWDELAY_H; |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
497 OWSETVPPOFF(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
498 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
499 tmp = OWReadByte(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
500 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
501 /* Check the bits we turned off are off */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
502 /* |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
503 for (i = 0; i < 8; i++) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
504 if (!(data[i] & 1 << i) && (tmp & 1 << i)) |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
505 return(-3); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
506 */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
507 if ((!data[i] & tmp) != 0) { |
| 41 | 508 cons_putsP(PSTR("Readback mismatch ")); |
| 509 cons_puts_hex(data[i]); | |
| 510 cons_putsP(PSTR(" vs ")); | |
| 511 cons_puts_hex(data[i]); | |
| 512 cons_putsP(PSTR("\r\n")); | |
|
33
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
513 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
514 OWTouchReset(); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
515 return(3); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
516 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
517 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
518 /* The DS2502 loads it's CRC register with the address of the |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
519 * next byte */ |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
520 crc = 0; |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
521 OWCRC(start + i + 1, &crc); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
522 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
523 |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
524 return(0); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
525 #else |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
526 return(1); |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
527 #endif |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
528 } |
|
0aa6bf4b98ae
- Don't wrap individual debug statements in ifdef, use a conditionally
darius
parents:
32
diff
changeset
|
529 |
| 41 | 530 /* |
| 531 * OWGetTemp | |
| 532 * | |
| 533 * Get the temperature from a 1wire bus module | |
| 534 * | |
| 535 * Returns temperature in hundredths of a degree or OW_TEMP_xxx on | |
| 536 * error. | |
| 537 */ | |
| 538 int16_t | |
| 539 OWGetTemp(uint8_t *ROM) { | |
| 540 int8_t i; | |
| 541 uint8_t crc, buf[9]; | |
| 542 int16_t temp; | |
| 543 int16_t tfrac; | |
| 544 | |
| 545 if (ROM[0] != OW_FAMILY_TEMP) | |
| 546 return OW_TEMP_WRONG_FAM; | |
| 547 | |
| 548 OWSendCmd(ROM, OW_CONVERTT_CMD); | |
| 549 | |
| 550 i = 0; | |
| 551 | |
| 552 /* Wait for the conversion */ | |
| 553 while (OWReadBit() == 0) | |
| 554 i = 1; | |
| 555 | |
| 556 /* Check that we talked to a module and it did something */ | |
| 557 if (i == 0) { | |
| 558 return OW_TEMP_NO_ROM; | |
| 559 } | |
| 560 | |
| 561 OWSendCmd(ROM, OW_RD_SCR_CMD); | |
| 562 crc = 0; | |
| 563 for (i = 0; i < 8; i++) { | |
| 564 buf[i] = OWReadByte(); | |
| 565 OWCRC(buf[i], &crc); | |
| 566 } | |
| 567 buf[i] = OWReadByte(); | |
| 568 if (crc != buf[8]) | |
| 569 return OW_TEMP_CRC_ERR; | |
| 570 temp = buf[0]; | |
| 571 if (buf[1] & 0x80) | |
| 572 temp -= 256; | |
| 573 | |
| 574 /* Chop off 0.5 degree bit */ | |
| 575 temp >>= 1; | |
| 576 | |
| 577 /* Calulate the fractional remainder */ | |
| 578 tfrac = buf[7] - buf[6]; | |
| 579 | |
| 580 /* Work in 100'th of degreess to save on floats */ | |
| 581 tfrac *= (int16_t)100; | |
| 582 | |
| 583 /* Divide by count */ | |
| 584 tfrac /= buf[7]; | |
| 585 | |
| 586 /* Subtract 0.25 deg from temp */ | |
| 587 tfrac += 75; | |
| 588 if (tfrac < 100) | |
| 589 temp--; | |
| 590 else | |
| 591 tfrac -= 100; | |
| 592 | |
| 593 i = temp; | |
| 594 temp *= 100; | |
| 595 temp += tfrac; | |
| 596 | |
| 597 return(temp); | |
| 598 } |