ds18x20 onewire temp sensor example

git-svn-id: https://svn.spreadspace.org/avr/trunk@210 aa12f405-d877-488e-9caf-2d797e2a1cc7

1 files changed, 571 insertions, 0 deletions

diff --git a/lib/onewire.c b/lib/onewire.c
new file mode 100644
index 0000000..b733b72
--- /dev/null
+++ b/lib/onewire.c
@@ -0,0 +1,571 @@
+/*
+Copyright (c) 2007, Jim Studt  (original old version - many contributors since)
+refactored from C++ to C by Bernhard Tittelbach
+
+The latest version of this library may be found at:
+  http://www.pjrc.com/teensy/td_libs_OneWire.html
+
+OneWire has been maintained by Paul Stoffregen (paul@pjrc.com) since
+January 2010.  At the time, it was in need of many bug fixes, but had
+been abandoned the original author (Jim Studt).  None of the known
+contributors were interested in maintaining OneWire.  Paul typically
+works on OneWire every 6 to 12 months.  Patches usually wait that
+long.  If anyone is interested in more actively maintaining OneWire,
+please contact Paul.
+
+Version 2.2:
+  Teensy 3.0 compatibility, Paul Stoffregen, paul@pjrc.com
+  Arduino Due compatibility, http://arduino.cc/forum/index.php?topic=141030
+  Fix DS18B20 example negative temperature
+  Fix DS18B20 example's low res modes, Ken Butcher
+  Improve reset timing, Mark Tillotson
+  Add const qualifiers, Bertrik Sikken
+  Add initial value input to crc16, Bertrik Sikken
+  Add target_search() function, Scott Roberts
+
+Version 2.1:
+  Arduino 1.0 compatibility, Paul Stoffregen
+  Improve temperature example, Paul Stoffregen
+  DS250x_PROM example, Guillermo Lovato
+  PIC32 (chipKit) compatibility, Jason Dangel, dangel.jason AT gmail.com
+  Improvements from Glenn Trewitt:
+  - crc16() now works
+  - check_crc16() does all of calculation/checking work.
+  - Added read_bytes() and write_bytes(), to reduce tedious loops.
+  - Added ds2408 example.
+  Delete very old, out-of-date readme file (info is here)
+
+Version 2.0: Modifications by Paul Stoffregen, January 2010:
+http://www.pjrc.com/teensy/td_libs_OneWire.html
+  Search fix from Robin James
+    http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
+  Use direct optimized I/O in all cases
+  Disable interrupts during timing critical sections
+    (this solves many random communication errors)
+  Disable interrupts during read-modify-write I/O
+  Reduce RAM consumption by eliminating unnecessary
+    variables and trimming many to 8 bits
+  Optimize both crc8 - table version moved to flash
+
+Modified to work with larger numbers of devices - avoids loop.
+Tested in Arduino 11 alpha with 12 sensors.
+26 Sept 2008 -- Robin James
+http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
+
+Updated to work with arduino-0008 and to include skip() as of
+2007/07/06. --RJL20
+
+Modified to calculate the 8-bit CRC directly, avoiding the need for
+the 256-byte lookup table to be loaded in RAM.  Tested in arduino-0010
+-- Tom Pollard, Jan 23, 2008
+
+Jim Studt's original library was modified by Josh Larios.
+
+Tom Pollard, pollard@alum.mit.edu, contributed around May 20, 2008
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Much of the code was inspired by Derek Yerger's code, though I don't
+think much of that remains.  In any event that was..
+    (copyleft) 2006 by Derek Yerger - Free to distribute freely.
+
+The CRC code was excerpted and inspired by the Dallas Semiconductor
+sample code bearing this copyright.
+//---------------------------------------------------------------------------
+// Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
+// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+// Except as contained in this notice, the name of Dallas Semiconductor
+// shall not be used except as stated in the Dallas Semiconductor
+// Branding Policy.
+//--------------------------------------------------------------------------
+*/
+
+#include "onewire.h"
+#include <util/delay.h>
+#include <avr/interrupt.h>
+
+
+IO_REG_TYPE owi_bitmask;
+volatile IO_REG_TYPE *owi_baseReg;
+#if ONEWIRE_SEARCH
+// global search state
+unsigned char ROM_NO[8];
+uint8_t owi_LastDiscrepancy;
+uint8_t owi_LastFamilyDiscrepancy;
+uint8_t owi_LastDeviceFlag;
+#endif
+
+
+void owi_init(uint8_t pin, volatile IO_REG_TYPE *pin_read_port)
+{
+    owi_bitmask = _BV(pin);
+	owi_baseReg = pin_read_port;
+    DIRECT_MODE_INPUT(owi_baseReg, owi_bitmask);
+#if ONEWIRE_SEARCH
+	owi_reset_search();
+#endif
+}
+
+
+// Perform the onewire reset function.  We will wait up to 250uS for
+// the bus to come high, if it doesn't then it is broken or shorted
+// and we return a 0;
+//
+// Returns 1 if a device asserted a presence pulse, 0 otherwise.
+//
+uint8_t owi_reset(void)
+{
+	IO_REG_TYPE mask = owi_bitmask;
+	register volatile IO_REG_TYPE *reg IO_REG_ASM = owi_baseReg;
+	uint8_t r;
+	uint8_t retries = 125;
+
+	cli();
+	DIRECT_MODE_INPUT(reg, mask);
+	sei();
+	// wait until the wire is high... just in case
+	do {
+		if (--retries == 0) return 0;
+		_delay_us(2);
+	} while ( !DIRECT_READ(reg, mask));
+
+	cli();
+	DIRECT_WRITE_LOW(reg, mask);
+	DIRECT_MODE_OUTPUT(reg, mask);	// drive output low
+	sei();
+	_delay_us(480);
+	cli();
+	DIRECT_MODE_INPUT(reg, mask);	// allow it to float
+	_delay_us(70);
+	r = !DIRECT_READ(reg, mask);
+	sei();
+	_delay_us(410);
+	return r;
+}
+
+//
+// Write a bit. Port and bit is used to cut lookup time and provide
+// more certain timing.
+//
+void owi_write_bit(uint8_t v)
+{
+	IO_REG_TYPE mask=owi_bitmask;
+	register volatile IO_REG_TYPE *reg IO_REG_ASM = owi_baseReg;
+
+	if (v & 1) {
+		cli();
+		DIRECT_WRITE_LOW(reg, mask);
+		DIRECT_MODE_OUTPUT(reg, mask);	// drive output low
+		_delay_us(10);
+		DIRECT_WRITE_HIGH(reg, mask);	// drive output high
+		sei();
+		_delay_us(55);
+	} else {
+		cli();
+		DIRECT_WRITE_LOW(reg, mask);
+		DIRECT_MODE_OUTPUT(reg, mask);	// drive output low
+		_delay_us(65);
+		DIRECT_WRITE_HIGH(reg, mask);	// drive output high
+		sei();
+		_delay_us(5);
+	}
+}
+
+//
+// Read a bit. Port and bit is used to cut lookup time and provide
+// more certain timing.
+//
+uint8_t owi_read_bit(void)
+{
+	IO_REG_TYPE mask=owi_bitmask;
+	register volatile IO_REG_TYPE *reg IO_REG_ASM = owi_baseReg;
+	uint8_t r;
+
+	cli();
+	DIRECT_MODE_OUTPUT(reg, mask);
+	DIRECT_WRITE_LOW(reg, mask);
+	_delay_us(3);
+	DIRECT_MODE_INPUT(reg, mask);	// let pin float, pull up will raise
+	_delay_us(10);
+	r = DIRECT_READ(reg, mask);
+	sei();
+	_delay_us(53);
+	return r;
+}
+
+//
+// Write a byte. The writing code uses the active drivers to raise the
+// pin high, if you need power after the write (e.g. DS18S20 in
+// parasite power mode) then set 'power' to 1, otherwise the pin will
+// go tri-state at the end of the write to avoid heating in a short or
+// other mishap.
+//
+void owi_write(uint8_t v, uint8_t power /* = 0 */) {
+    uint8_t bitMask;
+
+    for (bitMask = 0x01; bitMask; bitMask <<= 1) {
+	owi_write_bit( (bitMask & v)?1:0);
+    }
+    if ( !power) {
+	cli();
+	DIRECT_MODE_INPUT(owi_baseReg, owi_bitmask);
+	DIRECT_WRITE_LOW(owi_baseReg, owi_bitmask);
+	sei();
+    }
+}
+
+void owi_write_bytes(const uint8_t *buf, uint16_t count, bool power /* = 0 */) {
+  for (uint16_t i = 0 ; i < count ; i++)
+    owi_write(buf[i],0);
+  if (!power) {
+    cli();
+    DIRECT_MODE_INPUT(owi_baseReg, owi_bitmask);
+    DIRECT_WRITE_LOW(owi_baseReg, owi_bitmask);
+    sei();
+  }
+}
+
+//
+// Read a byte
+//
+uint8_t owi_read() {
+    uint8_t bitMask;
+    uint8_t r = 0;
+
+    for (bitMask = 0x01; bitMask; bitMask <<= 1) {
+	if ( owi_read_bit()) r |= bitMask;
+    }
+    return r;
+}
+
+void owi_read_bytes(uint8_t *buf, uint16_t count) {
+  for (uint16_t i = 0 ; i < count ; i++)
+    buf[i] = owi_read();
+}
+
+//
+// Do a ROM select
+//
+void owi_select(const uint8_t rom[8])
+{
+    uint8_t i;
+
+    owi_write(0x55,0);           // Choose ROM
+
+    for (i = 0; i < 8; i++) owi_write(rom[i],0);
+}
+
+//
+// Do a ROM skip
+//
+void owi_skip()
+{
+    owi_write(0xCC,0);           // Skip ROM
+}
+
+void owi_depower()
+{
+	cli();
+	DIRECT_MODE_INPUT(owi_baseReg, owi_bitmask);
+	sei();
+}
+
+#if ONEWIRE_SEARCH
+
+//
+// You need to use this function to start a search again from the beginning.
+// You do not need to do it for the first search, though you could.
+//
+void owi_reset_search()
+{
+  // reset the search state
+  owi_LastDiscrepancy = 0;
+  owi_LastDeviceFlag = FALSE;
+  owi_LastFamilyDiscrepancy = 0;
+  for(int i = 7; ; i--) {
+    ROM_NO[i] = 0;
+    if ( i == 0) break;
+  }
+}
+
+// Setup the search to find the device type 'family_code' on the next call
+// to search(*newAddr) if it is present.
+//
+void owi_target_search(uint8_t family_code)
+{
+   // set the search state to find SearchFamily type devices
+   ROM_NO[0] = family_code;
+   for (uint8_t i = 1; i < 8; i++)
+      ROM_NO[i] = 0;
+   owi_LastDiscrepancy = 64;
+   owi_LastFamilyDiscrepancy = 0;
+   owi_LastDeviceFlag = FALSE;
+}
+
+//
+// Perform a search. If this function returns a '1' then it has
+// enumerated the next device and you may retrieve the ROM from the
+// owi_address variable. If there are no devices, no further
+// devices, or something horrible happens in the middle of the
+// enumeration then a 0 is returned.  If a new device is found then
+// its address is copied to newAddr.  Use owi_reset_search() to
+// start over.
+//
+// --- Replaced by the one from the Dallas Semiconductor web site ---
+//--------------------------------------------------------------------------
+// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
+// search state.
+// Return TRUE  : device found, ROM number in ROM_NO buffer
+//        FALSE : device not found, end of search
+//
+uint8_t owi_search(uint8_t *newAddr)
+{
+   uint8_t id_bit_number;
+   uint8_t last_zero, rom_byte_number, search_result;
+   uint8_t id_bit, cmp_id_bit;
+
+   unsigned char rom_byte_mask, search_direction;
+
+   // initialize for search
+   id_bit_number = 1;
+   last_zero = 0;
+   rom_byte_number = 0;
+   rom_byte_mask = 1;
+   search_result = 0;
+
+   // if the last call was not the last one
+   if (!owi_LastDeviceFlag)
+   {
+      // 1-Wire reset
+      if (!owi_reset())
+      {
+         // reset the search
+         owi_LastDiscrepancy = 0;
+         owi_LastDeviceFlag = FALSE;
+         owi_LastFamilyDiscrepancy = 0;
+         return FALSE;
+      }
+
+      // issue the search command
+      owi_write(0xF0,0);
+
+      // loop to do the search
+      do
+      {
+         // read a bit and its complement
+         id_bit = owi_read_bit();
+         cmp_id_bit = owi_read_bit();
+
+         // check for no devices on 1-wire
+         if ((id_bit == 1) && (cmp_id_bit == 1))
+            break;
+         else
+         {
+            // all devices coupled have 0 or 1
+            if (id_bit != cmp_id_bit)
+               search_direction = id_bit;  // bit write value for search
+            else
+            {
+               // if this discrepancy if before the Last Discrepancy
+               // on a previous next then pick the same as last time
+               if (id_bit_number < owi_LastDiscrepancy)
+                  search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
+               else
+                  // if equal to last pick 1, if not then pick 0
+                  search_direction = (id_bit_number == owi_LastDiscrepancy);
+
+               // if 0 was picked then record its position in LastZero
+               if (search_direction == 0)
+               {
+                  last_zero = id_bit_number;
+
+                  // check for Last discrepancy in family
+                  if (last_zero < 9)
+                     owi_LastFamilyDiscrepancy = last_zero;
+               }
+            }
+
+            // set or clear the bit in the ROM byte rom_byte_number
+            // with mask rom_byte_mask
+            if (search_direction == 1)
+              ROM_NO[rom_byte_number] |= rom_byte_mask;
+            else
+              ROM_NO[rom_byte_number] &= ~rom_byte_mask;
+
+            // serial number search direction write bit
+            owi_write_bit(search_direction);
+
+            // increment the byte counter id_bit_number
+            // and shift the mask rom_byte_mask
+            id_bit_number++;
+            rom_byte_mask <<= 1;
+
+            // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
+            if (rom_byte_mask == 0)
+            {
+                rom_byte_number++;
+                rom_byte_mask = 1;
+            }
+         }
+      }
+      while(rom_byte_number < 8);  // loop until through all ROM bytes 0-7
+
+      // if the search was successful then
+      if (!(id_bit_number < 65))
+      {
+         // search successful so set owi_LastDiscrepancy,owi_LastDeviceFlag,search_result
+         owi_LastDiscrepancy = last_zero;
+
+         // check for last device
+         if (owi_LastDiscrepancy == 0)
+            owi_LastDeviceFlag = TRUE;
+
+         search_result = TRUE;
+      }
+   }
+
+   // if no device found then reset counters so next 'search' will be like a first
+   if (!search_result || !ROM_NO[0])
+   {
+      owi_LastDiscrepancy = 0;
+      owi_LastDeviceFlag = FALSE;
+      owi_LastFamilyDiscrepancy = 0;
+      search_result = FALSE;
+   }
+   for (int i = 0; i < 8; i++) newAddr[i] = ROM_NO[i];
+   return search_result;
+  }
+
+#endif
+
+#if ONEWIRE_CRC
+// The 1-Wire CRC scheme is described in Maxim Application Note 27:
+// "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products"
+//
+
+#if ONEWIRE_CRC8_TABLE
+// This table comes from Dallas sample code where it is freely reusable,
+// though Copyright (C) 2000 Dallas Semiconductor Corporation
+const uint8_t PROGMEM dscrc_table[] = {
+      0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
+    157,195, 33,127,252,162, 64, 30, 95,  1,227,189, 62, 96,130,220,
+     35,125,159,193, 66, 28,254,160,225,191, 93,  3,128,222, 60, 98,
+    190,224,  2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
+     70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89,  7,
+    219,133,103, 57,186,228,  6, 88, 25, 71,165,251,120, 38,196,154,
+    101, 59,217,135,  4, 90,184,230,167,249, 27, 69,198,152,122, 36,
+    248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91,  5,231,185,
+    140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
+     17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
+    175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
+     50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
+    202,148,118, 40,171,245, 23, 73,  8, 86,180,234,105, 55,213,139,
+     87,  9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
+    233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
+    116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};
+
+//
+// Compute a Dallas Semiconductor 8 bit CRC. These show up in the ROM
+// and the registers.  (note: this might better be done without to
+// table, it would probably be smaller and certainly fast enough
+// compared to all those delayMicrosecond() calls.  But I got
+// confused, so I use this table from the examples.)
+//
+uint8_t owi_crc8(const uint8_t *addr, uint8_t len)
+{
+	uint8_t crc = 0;
+
+	while (len--) {
+		crc = pgm_read_byte(dscrc_table + (crc ^ *addr++));
+	}
+	return crc;
+}
+#else
+//
+// Compute a Dallas Semiconductor 8 bit CRC directly.
+// this is much slower, but much smaller, than the lookup table.
+//
+uint8_t owi_crc8(const uint8_t *addr, uint8_t len)
+{
+	uint8_t crc = 0;
+	
+	while (len--) {
+		uint8_t inbyte = *addr++;
+		for (uint8_t i = 8; i; i--) {
+			uint8_t mix = (crc ^ inbyte) & 0x01;
+			crc >>= 1;
+			if (mix) crc ^= 0x8C;
+			inbyte >>= 1;
+		}
+	}
+	return crc;
+}
+#endif
+
+#if ONEWIRE_CRC16
+bool owi_check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc)
+{
+    crc = ~owi_crc16(input, len, crc);
+    return (crc & 0xFF) == inverted_crc[0] && (crc >> 8) == inverted_crc[1];
+}
+
+uint16_t owi_crc16(const uint8_t* input, uint16_t len, uint16_t crc)
+{
+    static const uint8_t oddparity[16] =
+        { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };
+
+    for (uint16_t i = 0 ; i < len ; i++) {
+      // Even though we're just copying a byte from the input,
+      // we'll be doing 16-bit computation with it.
+      uint16_t cdata = input[i];
+      cdata = (cdata ^ crc) & 0xff;
+      crc >>= 8;
+
+      if (oddparity[cdata & 0x0F] ^ oddparity[cdata >> 4])
+          crc ^= 0xC001;
+
+      cdata <<= 6;
+      crc ^= cdata;
+      cdata <<= 1;
+      crc ^= cdata;
+    }
+    return crc;
+}
+#endif
+
+#endif