--- /dev/null
+/*\r
+Copyright (c) 2007, Jim Studt\r
+\r
+\r
+Version 2.0: Modifications by Paul Stoffregen, January 2010:\r
+http://www.pjrc.com/teensy/td_libs_OneWire.html\r
+ Search fix from Robin James\r
+ http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27\r
+ Use direct optimized I/O in all cases\r
+ Disable interrupts during timing critical sections\r
+ (this solves many random communication errors)\r
+ Disable interrupts during read-modify-write I/O\r
+ Reduce RAM consumption by eliminating unnecessary\r
+ variables and trimming many to 8 bits\r
+ Optimize both crc8 - table version moved to flash\r
+\r
+Modified to work with larger numbers of devices - avoids loop.\r
+Tested in Arduino 11 alpha with 12 sensors.\r
+26 Sept 2008 -- Robin James\r
+http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27\r
+\r
+Updated to work with arduino-0008 and to include skip() as of\r
+2007/07/06. --RJL20\r
+\r
+Modified to calculate the 8-bit CRC directly, avoiding the need for\r
+the 256-byte lookup table to be loaded in RAM. Tested in arduino-0010\r
+-- Tom Pollard, Jan 23, 2008\r
+\r
+Permission is hereby granted, free of charge, to any person obtaining\r
+a copy of this software and associated documentation files (the\r
+"Software"), to deal in the Software without restriction, including\r
+without limitation the rights to use, copy, modify, merge, publish,\r
+distribute, sublicense, and/or sell copies of the Software, and to\r
+permit persons to whom the Software is furnished to do so, subject to\r
+the following conditions:\r
+\r
+The above copyright notice and this permission notice shall be\r
+included in all copies or substantial portions of the Software.\r
+\r
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
+\r
+Much of the code was inspired by Derek Yerger's code, though I don't\r
+think much of that remains. In any event that was..\r
+ (copyleft) 2006 by Derek Yerger - Free to distribute freely.\r
+\r
+The CRC code was excerpted and inspired by the Dallas Semiconductor\r
+sample code bearing this copyright.\r
+//---------------------------------------------------------------------------\r
+// Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.\r
+//\r
+// Permission is hereby granted, free of charge, to any person obtaining a\r
+// copy of this software and associated documentation files (the "Software"),\r
+// to deal in the Software without restriction, including without limitation\r
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,\r
+// and/or sell copies of the Software, and to permit persons to whom the\r
+// Software is furnished to do so, subject to the following conditions:\r
+//\r
+// The above copyright notice and this permission notice shall be included\r
+// in all copies or substantial portions of the Software.\r
+//\r
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS\r
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.\r
+// IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES\r
+// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,\r
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR\r
+// OTHER DEALINGS IN THE SOFTWARE.\r
+//\r
+// Except as contained in this notice, the name of Dallas Semiconductor\r
+// shall not be used except as stated in the Dallas Semiconductor\r
+// Branding Policy.\r
+//--------------------------------------------------------------------------\r
+*/\r
+\r
+#include "OneWire.h"\r
+#include "pins_arduino.h"\r
+\r
+extern "C" {\r
+#include "WConstants.h"\r
+#include <avr/io.h>\r
+#include <avr/interrupt.h>\r
+#include <avr/pgmspace.h>\r
+}\r
+\r
+OneWire::OneWire(uint8_t pin)\r
+{\r
+ bitmask = digitalPinToBitMask(pin);\r
+ baseReg = portInputRegister(digitalPinToPort(pin));\r
+#if ONEWIRE_SEARCH\r
+ reset_search();\r
+#endif\r
+}\r
+\r
+\r
+#define DIRECT_READ(base, mask) (((*(base)) & (mask)) ? 1 : 0)\r
+#define DIRECT_MODE_INPUT(base, mask) ((*(base+1)) &= ~(mask))\r
+#define DIRECT_MODE_OUTPUT(base, mask) ((*(base+1)) |= (mask))\r
+#define DIRECT_WRITE_LOW(base, mask) ((*(base+2)) &= ~(mask))\r
+#define DIRECT_WRITE_HIGH(base, mask) ((*(base+2)) |= (mask))\r
+\r
+\r
+// Perform the onewire reset function. We will wait up to 250uS for\r
+// the bus to come high, if it doesn't then it is broken or shorted\r
+// and we return a 0;\r
+//\r
+// Returns 1 if a device asserted a presence pulse, 0 otherwise.\r
+//\r
+uint8_t OneWire::reset(void)\r
+{\r
+ uint8_t mask=bitmask;\r
+ volatile uint8_t *reg asm("r30") = baseReg;\r
+ uint8_t r;\r
+ uint8_t retries = 125;\r
+\r
+ cli();\r
+ DIRECT_MODE_INPUT(reg, mask);\r
+ sei();\r
+ // wait until the wire is high... just in case\r
+ do {\r
+ if (--retries == 0) return 0;\r
+ delayMicroseconds(2);\r
+ } while ( !DIRECT_READ(reg, mask));\r
+\r
+ cli();\r
+ DIRECT_WRITE_LOW(reg, mask);\r
+ DIRECT_MODE_OUTPUT(reg, mask); // drive output low\r
+ sei();\r
+ delayMicroseconds(500);\r
+ cli();\r
+ DIRECT_MODE_INPUT(reg, mask); // allow it to float\r
+ delayMicroseconds(80);\r
+ r = !DIRECT_READ(reg, mask);\r
+ sei();\r
+ delayMicroseconds(420);\r
+ return r;\r
+}\r
+\r
+//\r
+// Write a bit. Port and bit is used to cut lookup time and provide\r
+// more certain timing.\r
+//\r
+void OneWire::write_bit(uint8_t v)\r
+{\r
+ uint8_t mask=bitmask;\r
+ volatile uint8_t *reg asm("r30") = baseReg;\r
+\r
+ if (v & 1) {\r
+ cli();\r
+ DIRECT_WRITE_LOW(reg, mask);\r
+ DIRECT_MODE_OUTPUT(reg, mask); // drive output low\r
+ delayMicroseconds(10);\r
+ DIRECT_WRITE_HIGH(reg, mask); // drive output high\r
+ sei();\r
+ delayMicroseconds(55);\r
+ } else {\r
+ cli();\r
+ DIRECT_WRITE_LOW(reg, mask);\r
+ DIRECT_MODE_OUTPUT(reg, mask); // drive output low\r
+ delayMicroseconds(65);\r
+ DIRECT_WRITE_HIGH(reg, mask); // drive output high\r
+ sei();\r
+ delayMicroseconds(5);\r
+ }\r
+}\r
+\r
+//\r
+// Read a bit. Port and bit is used to cut lookup time and provide\r
+// more certain timing.\r
+//\r
+uint8_t OneWire::read_bit(void)\r
+{\r
+ uint8_t mask=bitmask;\r
+ volatile uint8_t *reg asm("r30") = baseReg;\r
+ uint8_t r;\r
+\r
+ cli();\r
+ DIRECT_MODE_OUTPUT(reg, mask);\r
+ DIRECT_WRITE_LOW(reg, mask);\r
+ delayMicroseconds(3);\r
+ DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise\r
+ delayMicroseconds(9);\r
+ r = DIRECT_READ(reg, mask);\r
+ sei();\r
+ delayMicroseconds(53);\r
+ return r;\r
+}\r
+\r
+//\r
+// Write a byte. The writing code uses the active drivers to raise the\r
+// pin high, if you need power after the write (e.g. DS18S20 in\r
+// parasite power mode) then set 'power' to 1, otherwise the pin will\r
+// go tri-state at the end of the write to avoid heating in a short or\r
+// other mishap.\r
+//\r
+void OneWire::write(uint8_t v, uint8_t power /* = 0 */) {\r
+ uint8_t bitMask;\r
+\r
+ for (bitMask = 0x01; bitMask; bitMask <<= 1) {\r
+ OneWire::write_bit( (bitMask & v)?1:0);\r
+ }\r
+ if ( !power) {\r
+ cli();\r
+ DIRECT_MODE_INPUT(baseReg, bitmask);\r
+ DIRECT_WRITE_LOW(baseReg, bitmask);\r
+ sei();\r
+ }\r
+}\r
+\r
+//\r
+// Read a byte\r
+//\r
+uint8_t OneWire::read() {\r
+ uint8_t bitMask;\r
+ uint8_t r = 0;\r
+\r
+ for (bitMask = 0x01; bitMask; bitMask <<= 1) {\r
+ if ( OneWire::read_bit()) r |= bitMask;\r
+ }\r
+ return r;\r
+}\r
+\r
+//\r
+// Do a ROM select\r
+//\r
+void OneWire::select( uint8_t rom[8])\r
+{\r
+ int i;\r
+\r
+ write(0x55); // Choose ROM\r
+\r
+ for( i = 0; i < 8; i++) write(rom[i]);\r
+}\r
+\r
+//\r
+// Do a ROM skip\r
+//\r
+void OneWire::skip()\r
+{\r
+ write(0xCC); // Skip ROM\r
+}\r
+\r
+void OneWire::depower()\r
+{\r
+ cli();\r
+ DIRECT_MODE_INPUT(baseReg, bitmask);\r
+ sei();\r
+}\r
+\r
+#if ONEWIRE_SEARCH\r
+\r
+//\r
+// You need to use this function to start a search again from the beginning.\r
+// You do not need to do it for the first search, though you could.\r
+//\r
+void OneWire::reset_search()\r
+ {\r
+ // reset the search state\r
+ LastDiscrepancy = 0;\r
+ LastDeviceFlag = FALSE;\r
+ LastFamilyDiscrepancy = 0;\r
+ for(int i = 7; ; i--)\r
+ {\r
+ ROM_NO[i] = 0;\r
+ if ( i == 0) break;\r
+ }\r
+ }\r
+\r
+//\r
+// Perform a search. If this function returns a '1' then it has\r
+// enumerated the next device and you may retrieve the ROM from the\r
+// OneWire::address variable. If there are no devices, no further\r
+// devices, or something horrible happens in the middle of the\r
+// enumeration then a 0 is returned. If a new device is found then\r
+// its address is copied to newAddr. Use OneWire::reset_search() to\r
+// start over.\r
+//\r
+// --- Replaced by the one from the Dallas Semiconductor web site ---\r
+//--------------------------------------------------------------------------\r
+// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing\r
+// search state.\r
+// Return TRUE : device found, ROM number in ROM_NO buffer\r
+// FALSE : device not found, end of search\r
+//\r
+uint8_t OneWire::search(uint8_t *newAddr)\r
+{\r
+ uint8_t id_bit_number;\r
+ uint8_t last_zero, rom_byte_number, search_result;\r
+ uint8_t id_bit, cmp_id_bit;\r
+\r
+ unsigned char rom_byte_mask, search_direction;\r
+\r
+ // initialize for search\r
+ id_bit_number = 1;\r
+ last_zero = 0;\r
+ rom_byte_number = 0;\r
+ rom_byte_mask = 1;\r
+ search_result = 0;\r
+\r
+ // if the last call was not the last one\r
+ if (!LastDeviceFlag)\r
+ {\r
+ // 1-Wire reset\r
+ if (!reset())\r
+ {\r
+ // reset the search\r
+ LastDiscrepancy = 0;\r
+ LastDeviceFlag = FALSE;\r
+ LastFamilyDiscrepancy = 0;\r
+ return FALSE;\r
+ }\r
+\r
+ // issue the search command\r
+ write(0xF0);\r
+\r
+ // loop to do the search\r
+ do\r
+ {\r
+ // read a bit and its complement\r
+ id_bit = read_bit();\r
+ cmp_id_bit = read_bit();\r
+\r
+ // check for no devices on 1-wire\r
+ if ((id_bit == 1) && (cmp_id_bit == 1))\r
+ break;\r
+ else\r
+ {\r
+ // all devices coupled have 0 or 1\r
+ if (id_bit != cmp_id_bit)\r
+ search_direction = id_bit; // bit write value for search\r
+ else\r
+ {\r
+ // if this discrepancy if before the Last Discrepancy\r
+ // on a previous next then pick the same as last time\r
+ if (id_bit_number < LastDiscrepancy)\r
+ search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);\r
+ else\r
+ // if equal to last pick 1, if not then pick 0\r
+ search_direction = (id_bit_number == LastDiscrepancy);\r
+\r
+ // if 0 was picked then record its position in LastZero\r
+ if (search_direction == 0)\r
+ {\r
+ last_zero = id_bit_number;\r
+\r
+ // check for Last discrepancy in family\r
+ if (last_zero < 9)\r
+ LastFamilyDiscrepancy = last_zero;\r
+ }\r
+ }\r
+\r
+ // set or clear the bit in the ROM byte rom_byte_number\r
+ // with mask rom_byte_mask\r
+ if (search_direction == 1)\r
+ ROM_NO[rom_byte_number] |= rom_byte_mask;\r
+ else\r
+ ROM_NO[rom_byte_number] &= ~rom_byte_mask;\r
+\r
+ // serial number search direction write bit\r
+ write_bit(search_direction);\r
+\r
+ // increment the byte counter id_bit_number\r
+ // and shift the mask rom_byte_mask\r
+ id_bit_number++;\r
+ rom_byte_mask <<= 1;\r
+\r
+ // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask\r
+ if (rom_byte_mask == 0)\r
+ {\r
+ rom_byte_number++;\r
+ rom_byte_mask = 1;\r
+ }\r
+ }\r
+ }\r
+ while(rom_byte_number < 8); // loop until through all ROM bytes 0-7\r
+\r
+ // if the search was successful then\r
+ if (!(id_bit_number < 65))\r
+ {\r
+ // search successful so set LastDiscrepancy,LastDeviceFlag,search_result\r
+ LastDiscrepancy = last_zero;\r
+\r
+ // check for last device\r
+ if (LastDiscrepancy == 0)\r
+ LastDeviceFlag = TRUE;\r
+\r
+ search_result = TRUE;\r
+ }\r
+ }\r
+\r
+ // if no device found then reset counters so next 'search' will be like a first\r
+ if (!search_result || !ROM_NO[0])\r
+ {\r
+ LastDiscrepancy = 0;\r
+ LastDeviceFlag = FALSE;\r
+ LastFamilyDiscrepancy = 0;\r
+ search_result = FALSE;\r
+ }\r
+ for (int i = 0; i < 8; i++) newAddr[i] = ROM_NO[i];\r
+ return search_result;\r
+ }\r
+\r
+#endif\r
+\r
+#if ONEWIRE_CRC\r
+// The 1-Wire CRC scheme is described in Maxim Application Note 27:\r
+// "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products"\r
+//\r
+\r
+#if ONEWIRE_CRC8_TABLE\r
+// This table comes from Dallas sample code where it is freely reusable,\r
+// though Copyright (C) 2000 Dallas Semiconductor Corporation\r
+static const uint8_t PROGMEM dscrc_table[] = {\r
+ 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,\r
+ 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,\r
+ 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,\r
+ 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,\r
+ 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,\r
+ 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,\r
+ 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,\r
+ 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,\r
+ 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,\r
+ 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,\r
+ 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,\r
+ 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,\r
+ 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,\r
+ 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,\r
+ 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,\r
+ 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};\r
+\r
+//\r
+// Compute a Dallas Semiconductor 8 bit CRC. These show up in the ROM\r
+// and the registers. (note: this might better be done without to\r
+// table, it would probably be smaller and certainly fast enough\r
+// compared to all those delayMicrosecond() calls. But I got\r
+// confused, so I use this table from the examples.)\r
+//\r
+uint8_t OneWire::crc8( uint8_t *addr, uint8_t len)\r
+{\r
+ uint8_t crc = 0;\r
+\r
+ while (len--) {\r
+ crc = pgm_read_byte(dscrc_table + (crc ^ *addr++));\r
+ }\r
+ return crc;\r
+}\r
+#else\r
+//\r
+// Compute a Dallas Semiconductor 8 bit CRC directly.\r
+//\r
+uint8_t OneWire::crc8( uint8_t *addr, uint8_t len)\r
+{\r
+ uint8_t crc = 0;\r
+ \r
+ while (len--) {\r
+ uint8_t inbyte = *addr++;\r
+ for (uint8_t i = 8; i; i--) {\r
+ uint8_t mix = (crc ^ inbyte) & 0x01;\r
+ crc >>= 1;\r
+ if (mix) crc ^= 0x8C;\r
+ inbyte >>= 1;\r
+ }\r
+ }\r
+ return crc;\r
+}\r
+#endif\r
+\r
+#if ONEWIRE_CRC16\r
+static short oddparity[16] = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };\r
+\r
+//\r
+// Compute a Dallas Semiconductor 16 bit CRC. I have never seen one of\r
+// these, but here it is.\r
+//\r
+unsigned short OneWire::crc16(unsigned short *data, unsigned short len)\r
+{\r
+ unsigned short i;\r
+ unsigned short crc = 0;\r
+\r
+ for ( i = 0; i < len; i++) {\r
+ unsigned short cdata = data[len];\r
+\r
+ cdata = (cdata ^ (crc & 0xff)) & 0xff;\r
+ crc >>= 8;\r
+\r
+ if (oddparity[cdata & 0xf] ^ oddparity[cdata >> 4]) crc ^= 0xc001;\r
+\r
+ cdata <<= 6;\r
+ crc ^= cdata;\r
+ cdata <<= 1;\r
+ crc ^= cdata;\r
+ }\r
+ return crc;\r
+}\r
+#endif\r
+\r
+#endif\r
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