1-Wire - 1-Wire implementation, using DS2480B controller i…

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Paul van der Wielen / Mbed 2 deprecated 1-Wire

1-Wire implementation, using DS2480B controller interfaced with serial port, working example to read DS18B20, based on work already in progress / Dallas - Public domain code

Dependencies: mbed

ownet.cpp@0:1193dbfe28e2, 2011-03-24 (annotated)

Committer:: pwheels
Date:: Thu Mar 24 17:21:29 2011 +0000
Revision:: 0:1193dbfe28e2

Who changed what in which revision?

User	Revision	Line number	New contents of line
pwheels	0:1193dbfe28e2	1	//---------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	2	// Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.
pwheels	0:1193dbfe28e2	3	//
pwheels	0:1193dbfe28e2	4	// Permission is hereby granted, free of charge, to any person obtaining a
pwheels	0:1193dbfe28e2	5	// copy of this software and associated documentation files (the "Software"),
pwheels	0:1193dbfe28e2	6	// to deal in the Software without restriction, including without limitation
pwheels	0:1193dbfe28e2	7	// the rights to use, copy, modify, merge, publish, distribute, sublicense,
pwheels	0:1193dbfe28e2	8	// and/or sell copies of the Software, and to permit persons to whom the
pwheels	0:1193dbfe28e2	9	// Software is furnished to do so, subject to the following conditions:
pwheels	0:1193dbfe28e2	10	//
pwheels	0:1193dbfe28e2	11	// The above copyright notice and this permission notice shall be included
pwheels	0:1193dbfe28e2	12	// in all copies or substantial portions of the Software.
pwheels	0:1193dbfe28e2	13	//
pwheels	0:1193dbfe28e2	14	// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
pwheels	0:1193dbfe28e2	15	// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
pwheels	0:1193dbfe28e2	16	// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
pwheels	0:1193dbfe28e2	17	// IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
pwheels	0:1193dbfe28e2	18	// OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
pwheels	0:1193dbfe28e2	19	// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
pwheels	0:1193dbfe28e2	20	// OTHER DEALINGS IN THE SOFTWARE.
pwheels	0:1193dbfe28e2	21	//
pwheels	0:1193dbfe28e2	22	// Except as contained in this notice, the name of Dallas Semiconductor
pwheels	0:1193dbfe28e2	23	// shall not be used except as stated in the Dallas Semiconductor
pwheels	0:1193dbfe28e2	24	// Branding Policy.
pwheels	0:1193dbfe28e2	25	//---------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	26	//
pwheels	0:1193dbfe28e2	27	// ownet.C - Network functions for 1-Wire net devices.
pwheels	0:1193dbfe28e2	28	//
pwheels	0:1193dbfe28e2	29	// Version: 3.00
pwheels	0:1193dbfe28e2	30	//
pwheels	0:1193dbfe28e2	31	// History: 1.00 -> 1.01 Change to owFamilySearchSetup, LastDiscrepancy[portnum]
pwheels	0:1193dbfe28e2	32	// was set to 64 instead of 8 to enable devices with
pwheels	0:1193dbfe28e2	33	// early contention to go in the '0' direction first.
pwheels	0:1193dbfe28e2	34	// 1.02 -> 1.03 Initialized goodbits in owVerify
pwheels	0:1193dbfe28e2	35	// 1.03 -> 2.00 Changed 'MLan' to 'ow'. Added support for
pwheels	0:1193dbfe28e2	36	// multiple ports.
pwheels	0:1193dbfe28e2	37	// 2.00 -> 2.01 Added support for owError library
pwheels	0:1193dbfe28e2	38	// 2.01 -> 3.00 Make search functions consistent with AN187
pwheels	0:1193dbfe28e2	39	//
pwheels	0:1193dbfe28e2	40
pwheels	0:1193dbfe28e2	41	#include <stdio.h>
pwheels	0:1193dbfe28e2	42	#include "ownet.h"
pwheels	0:1193dbfe28e2	43
pwheels	0:1193dbfe28e2	44	// exportable functions defined in ownet.c
pwheels	0:1193dbfe28e2	45	SMALLINT bitacc(SMALLINT,SMALLINT,SMALLINT,uchar *);
pwheels	0:1193dbfe28e2	46
pwheels	0:1193dbfe28e2	47	// global variables for this module to hold search state information
pwheels	0:1193dbfe28e2	48	static SMALLINT LastDiscrepancy[MAX_PORTNUM];
pwheels	0:1193dbfe28e2	49	static SMALLINT LastFamilyDiscrepancy[MAX_PORTNUM];
pwheels	0:1193dbfe28e2	50	static SMALLINT LastDevice[MAX_PORTNUM];
pwheels	0:1193dbfe28e2	51	uchar SerialNum[MAX_PORTNUM][8];
pwheels	0:1193dbfe28e2	52
pwheels	0:1193dbfe28e2	53	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	54	// The 'owFirst' finds the first device on the 1-Wire Net This function
pwheels	0:1193dbfe28e2	55	// contains one parameter 'alarm_only'. When
pwheels	0:1193dbfe28e2	56	// 'alarm_only' is TRUE (1) the find alarm command 0xEC is
pwheels	0:1193dbfe28e2	57	// sent instead of the normal search command 0xF0.
pwheels	0:1193dbfe28e2	58	// Using the find alarm command 0xEC will limit the search to only
pwheels	0:1193dbfe28e2	59	// 1-Wire devices that are in an 'alarm' state.
pwheels	0:1193dbfe28e2	60	//
pwheels	0:1193dbfe28e2	61	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	62	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	63	// 'do_reset' - TRUE (1) perform reset before search, FALSE (0) do not
pwheels	0:1193dbfe28e2	64	// perform reset before search.
pwheels	0:1193dbfe28e2	65	// 'alarm_only' - TRUE (1) the find alarm command 0xEC is
pwheels	0:1193dbfe28e2	66	// sent instead of the normal search command 0xF0
pwheels	0:1193dbfe28e2	67	//
pwheels	0:1193dbfe28e2	68	// Returns: TRUE (1) : when a 1-Wire device was found and it's
pwheels	0:1193dbfe28e2	69	// Serial Number placed in the global SerialNum[portnum]
pwheels	0:1193dbfe28e2	70	// FALSE (0): There are no devices on the 1-Wire Net.
pwheels	0:1193dbfe28e2	71	//
pwheels	0:1193dbfe28e2	72	SMALLINT owFirst(int portnum, SMALLINT do_reset, SMALLINT alarm_only)
pwheels	0:1193dbfe28e2	73	{
pwheels	0:1193dbfe28e2	74	// reset the search state
pwheels	0:1193dbfe28e2	75	LastDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	76	LastDevice[portnum] = FALSE;
pwheels	0:1193dbfe28e2	77	LastFamilyDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	78
pwheels	0:1193dbfe28e2	79	return owNext(portnum,do_reset,alarm_only);
pwheels	0:1193dbfe28e2	80	}
pwheels	0:1193dbfe28e2	81
pwheels	0:1193dbfe28e2	82	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	83	// The 'owNext' function does a general search. This function
pwheels	0:1193dbfe28e2	84	// continues from the previos search state. The search state
pwheels	0:1193dbfe28e2	85	// can be reset by using the 'owFirst' function.
pwheels	0:1193dbfe28e2	86	// This function contains one parameter 'alarm_only'.
pwheels	0:1193dbfe28e2	87	// When 'alarm_only' is TRUE (1) the find alarm command
pwheels	0:1193dbfe28e2	88	// 0xEC is sent instead of the normal search command 0xF0.
pwheels	0:1193dbfe28e2	89	// Using the find alarm command 0xEC will limit the search to only
pwheels	0:1193dbfe28e2	90	// 1-Wire devices that are in an 'alarm' state.
pwheels	0:1193dbfe28e2	91	//
pwheels	0:1193dbfe28e2	92	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	93	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	94	// 'do_reset' - TRUE (1) perform reset before search, FALSE (0) do not
pwheels	0:1193dbfe28e2	95	// perform reset before search.
pwheels	0:1193dbfe28e2	96	// 'alarm_only' - TRUE (1) the find alarm command 0xEC is
pwheels	0:1193dbfe28e2	97	// sent instead of the normal search command 0xF0
pwheels	0:1193dbfe28e2	98	//
pwheels	0:1193dbfe28e2	99	// Returns: TRUE (1) : when a 1-Wire device was found and it's
pwheels	0:1193dbfe28e2	100	// Serial Number placed in the global SerialNum[portnum]
pwheels	0:1193dbfe28e2	101	// FALSE (0): when no new device was found. Either the
pwheels	0:1193dbfe28e2	102	// last search was the last device or there
pwheels	0:1193dbfe28e2	103	// are no devices on the 1-Wire Net.
pwheels	0:1193dbfe28e2	104	//
pwheels	0:1193dbfe28e2	105	SMALLINT owNext(int portnum, SMALLINT do_reset, SMALLINT alarm_only)
pwheels	0:1193dbfe28e2	106	{
pwheels	0:1193dbfe28e2	107	uchar bit_test, search_direction, bit_number;
pwheels	0:1193dbfe28e2	108	uchar last_zero, serial_byte_number, next_result;
pwheels	0:1193dbfe28e2	109	uchar serial_byte_mask;
pwheels	0:1193dbfe28e2	110	uchar lastcrc8=0;
pwheels	0:1193dbfe28e2	111
pwheels	0:1193dbfe28e2	112	// initialize for search
pwheels	0:1193dbfe28e2	113	bit_number = 1;
pwheels	0:1193dbfe28e2	114	last_zero = 0;
pwheels	0:1193dbfe28e2	115	serial_byte_number = 0;
pwheels	0:1193dbfe28e2	116	serial_byte_mask = 1;
pwheels	0:1193dbfe28e2	117	next_result = 0;
pwheels	0:1193dbfe28e2	118	setcrc8(portnum,0);
pwheels	0:1193dbfe28e2	119
pwheels	0:1193dbfe28e2	120	// if the last call was not the last one
pwheels	0:1193dbfe28e2	121	if (!LastDevice[portnum])
pwheels	0:1193dbfe28e2	122	{
pwheels	0:1193dbfe28e2	123	// check if reset first is requested
pwheels	0:1193dbfe28e2	124	if (do_reset)
pwheels	0:1193dbfe28e2	125	{
pwheels	0:1193dbfe28e2	126	// reset the 1-wire
pwheels	0:1193dbfe28e2	127	// if there are no parts on 1-wire, return FALSE
pwheels	0:1193dbfe28e2	128	if (!owTouchReset(portnum))
pwheels	0:1193dbfe28e2	129	{
pwheels	0:1193dbfe28e2	130	// printf("owTouchReset failed\r\n");
pwheels	0:1193dbfe28e2	131	// reset the search
pwheels	0:1193dbfe28e2	132	LastDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	133	LastFamilyDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	134	OWERROR(OWERROR_NO_DEVICES_ON_NET);
pwheels	0:1193dbfe28e2	135	return FALSE;
pwheels	0:1193dbfe28e2	136	}
pwheels	0:1193dbfe28e2	137	}
pwheels	0:1193dbfe28e2	138
pwheels	0:1193dbfe28e2	139	// If finding alarming devices issue a different command
pwheels	0:1193dbfe28e2	140	if (alarm_only)
pwheels	0:1193dbfe28e2	141	owWriteByte(portnum,0xEC); // issue the alarming search command
pwheels	0:1193dbfe28e2	142	else
pwheels	0:1193dbfe28e2	143	owWriteByte(portnum,0xF0); // issue the search command
pwheels	0:1193dbfe28e2	144
pwheels	0:1193dbfe28e2	145	//pause before beginning the search
pwheels	0:1193dbfe28e2	146	//usDelay(100);
pwheels	0:1193dbfe28e2	147
pwheels	0:1193dbfe28e2	148	// loop to do the search
pwheels	0:1193dbfe28e2	149	do
pwheels	0:1193dbfe28e2	150	{
pwheels	0:1193dbfe28e2	151	// read a bit and its compliment
pwheels	0:1193dbfe28e2	152	bit_test = owTouchBit(portnum,1) << 1;
pwheels	0:1193dbfe28e2	153	bit_test \|= owTouchBit(portnum,1);
pwheels	0:1193dbfe28e2	154
pwheels	0:1193dbfe28e2	155	// check for no devices on 1-wire
pwheels	0:1193dbfe28e2	156	if (bit_test == 3)
pwheels	0:1193dbfe28e2	157	break;
pwheels	0:1193dbfe28e2	158	else
pwheels	0:1193dbfe28e2	159	{
pwheels	0:1193dbfe28e2	160	// all devices coupled have 0 or 1
pwheels	0:1193dbfe28e2	161	if (bit_test > 0)
pwheels	0:1193dbfe28e2	162	search_direction = !(bit_test & 0x01); // bit write value for search
pwheels	0:1193dbfe28e2	163	else
pwheels	0:1193dbfe28e2	164	{
pwheels	0:1193dbfe28e2	165	// if this discrepancy if before the Last Discrepancy
pwheels	0:1193dbfe28e2	166	// on a previous next then pick the same as last time
pwheels	0:1193dbfe28e2	167	if (bit_number < LastDiscrepancy[portnum])
pwheels	0:1193dbfe28e2	168	search_direction = ((SerialNum[portnum][serial_byte_number] & serial_byte_mask) > 0);
pwheels	0:1193dbfe28e2	169	else
pwheels	0:1193dbfe28e2	170	// if equal to last pick 1, if not then pick 0
pwheels	0:1193dbfe28e2	171	search_direction = (bit_number == LastDiscrepancy[portnum]);
pwheels	0:1193dbfe28e2	172
pwheels	0:1193dbfe28e2	173	// if 0 was picked then record its position in LastZero
pwheels	0:1193dbfe28e2	174	if (search_direction == 0)
pwheels	0:1193dbfe28e2	175	{
pwheels	0:1193dbfe28e2	176	last_zero = bit_number;
pwheels	0:1193dbfe28e2	177
pwheels	0:1193dbfe28e2	178	// check for Last discrepancy in family
pwheels	0:1193dbfe28e2	179	if (last_zero < 9)
pwheels	0:1193dbfe28e2	180	LastFamilyDiscrepancy[portnum] = last_zero;
pwheels	0:1193dbfe28e2	181	}
pwheels	0:1193dbfe28e2	182	}
pwheels	0:1193dbfe28e2	183
pwheels	0:1193dbfe28e2	184	// set or clear the bit in the SerialNum[portnum] byte serial_byte_number
pwheels	0:1193dbfe28e2	185	// with mask serial_byte_mask
pwheels	0:1193dbfe28e2	186	if (search_direction == 1)
pwheels	0:1193dbfe28e2	187	SerialNum[portnum][serial_byte_number] \|= serial_byte_mask;
pwheels	0:1193dbfe28e2	188	else
pwheels	0:1193dbfe28e2	189	SerialNum[portnum][serial_byte_number] &= ~serial_byte_mask;
pwheels	0:1193dbfe28e2	190
pwheels	0:1193dbfe28e2	191	// serial number search direction write bit
pwheels	0:1193dbfe28e2	192	owTouchBit(portnum,search_direction);
pwheels	0:1193dbfe28e2	193
pwheels	0:1193dbfe28e2	194	// increment the byte counter bit_number
pwheels	0:1193dbfe28e2	195	// and shift the mask serial_byte_mask
pwheels	0:1193dbfe28e2	196	bit_number++;
pwheels	0:1193dbfe28e2	197	serial_byte_mask <<= 1;
pwheels	0:1193dbfe28e2	198
pwheels	0:1193dbfe28e2	199	// if the mask is 0 then go to new SerialNum[portnum] byte serial_byte_number
pwheels	0:1193dbfe28e2	200	// and reset mask
pwheels	0:1193dbfe28e2	201	if (serial_byte_mask == 0)
pwheels	0:1193dbfe28e2	202	{
pwheels	0:1193dbfe28e2	203	// The below has been added to accomidate the valid CRC with the
pwheels	0:1193dbfe28e2	204	// possible changing serial number values of the DS28E04.
pwheels	0:1193dbfe28e2	205	if (((SerialNum[portnum][0] & 0x7F) == 0x1C) && (serial_byte_number == 1))
pwheels	0:1193dbfe28e2	206	lastcrc8 = docrc8(portnum,0x7F);
pwheels	0:1193dbfe28e2	207	else
pwheels	0:1193dbfe28e2	208	lastcrc8 = docrc8(portnum,SerialNum[portnum][serial_byte_number]); // accumulate the CRC
pwheels	0:1193dbfe28e2	209
pwheels	0:1193dbfe28e2	210	serial_byte_number++;
pwheels	0:1193dbfe28e2	211	serial_byte_mask = 1;
pwheels	0:1193dbfe28e2	212	}
pwheels	0:1193dbfe28e2	213	}
pwheels	0:1193dbfe28e2	214	}
pwheels	0:1193dbfe28e2	215	while(serial_byte_number < 8); // loop until through all SerialNum[portnum] bytes 0-7
pwheels	0:1193dbfe28e2	216
pwheels	0:1193dbfe28e2	217	// if the search was successful then
pwheels	0:1193dbfe28e2	218	if (!((bit_number < 65) \|\| lastcrc8))
pwheels	0:1193dbfe28e2	219	{
pwheels	0:1193dbfe28e2	220	// search successful so set LastDiscrepancy[portnum],LastDevice[portnum],next_result
pwheels	0:1193dbfe28e2	221	LastDiscrepancy[portnum] = last_zero;
pwheels	0:1193dbfe28e2	222	LastDevice[portnum] = (LastDiscrepancy[portnum] == 0);
pwheels	0:1193dbfe28e2	223	next_result = TRUE;
pwheels	0:1193dbfe28e2	224	}
pwheels	0:1193dbfe28e2	225	}
pwheels	0:1193dbfe28e2	226
pwheels	0:1193dbfe28e2	227	// if no device found then reset counters so next 'next' will be
pwheels	0:1193dbfe28e2	228	// like a first
pwheels	0:1193dbfe28e2	229	if (!next_result \|\| !SerialNum[portnum][0])
pwheels	0:1193dbfe28e2	230	{
pwheels	0:1193dbfe28e2	231	LastDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	232	LastDevice[portnum] = FALSE;
pwheels	0:1193dbfe28e2	233	LastFamilyDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	234	next_result = FALSE;
pwheels	0:1193dbfe28e2	235	}
pwheels	0:1193dbfe28e2	236
pwheels	0:1193dbfe28e2	237	return next_result;
pwheels	0:1193dbfe28e2	238	}
pwheels	0:1193dbfe28e2	239
pwheels	0:1193dbfe28e2	240	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	241	// The 'owSerialNum' function either reads or sets the SerialNum buffer
pwheels	0:1193dbfe28e2	242	// that is used in the search functions 'owFirst' and 'owNext'.
pwheels	0:1193dbfe28e2	243	// This function contains two parameters, 'serialnum_buf' is a pointer
pwheels	0:1193dbfe28e2	244	// to a buffer provided by the caller. 'serialnum_buf' should point to
pwheels	0:1193dbfe28e2	245	// an array of 8 unsigned chars. The second parameter is a flag called
pwheels	0:1193dbfe28e2	246	// 'do_read' that is TRUE (1) if the operation is to read and FALSE
pwheels	0:1193dbfe28e2	247	// (0) if the operation is to set the internal SerialNum buffer from
pwheels	0:1193dbfe28e2	248	// the data in the provided buffer.
pwheels	0:1193dbfe28e2	249	//
pwheels	0:1193dbfe28e2	250	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	251	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	252	// 'serialnum_buf' - buffer to that contains the serial number to set
pwheels	0:1193dbfe28e2	253	// when do_read = FALSE (0) and buffer to get the serial
pwheels	0:1193dbfe28e2	254	// number when do_read = TRUE (1).
pwheels	0:1193dbfe28e2	255	// 'do_read' - flag to indicate reading (1) or setting (0) the current
pwheels	0:1193dbfe28e2	256	// serial number.
pwheels	0:1193dbfe28e2	257	//
pwheels	0:1193dbfe28e2	258	void owSerialNum(int portnum, uchar *serialnum_buf, SMALLINT do_read)
pwheels	0:1193dbfe28e2	259	{
pwheels	0:1193dbfe28e2	260	uchar i;
pwheels	0:1193dbfe28e2	261
pwheels	0:1193dbfe28e2	262	// read the internal buffer and place in 'serialnum_buf'
pwheels	0:1193dbfe28e2	263	if (do_read)
pwheels	0:1193dbfe28e2	264	{
pwheels	0:1193dbfe28e2	265	for (i = 0; i < 8; i++)
pwheels	0:1193dbfe28e2	266	serialnum_buf[i] = SerialNum[portnum][i];
pwheels	0:1193dbfe28e2	267	}
pwheels	0:1193dbfe28e2	268	// set the internal buffer from the data in 'serialnum_buf'
pwheels	0:1193dbfe28e2	269	else
pwheels	0:1193dbfe28e2	270	{
pwheels	0:1193dbfe28e2	271	for (i = 0; i < 8; i++)
pwheels	0:1193dbfe28e2	272	SerialNum[portnum][i] = serialnum_buf[i];
pwheels	0:1193dbfe28e2	273	}
pwheels	0:1193dbfe28e2	274	}
pwheels	0:1193dbfe28e2	275
pwheels	0:1193dbfe28e2	276	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	277	// Setup the search algorithm to find a certain family of devices
pwheels	0:1193dbfe28e2	278	// the next time a search function is called 'owNext'.
pwheels	0:1193dbfe28e2	279	//
pwheels	0:1193dbfe28e2	280	// 'portnum' - number 0 to MAX_PORTNUM-1. This number was provided to
pwheels	0:1193dbfe28e2	281	// OpenCOM to indicate the port number.
pwheels	0:1193dbfe28e2	282	// 'search_family' - family code type to set the search algorithm to find
pwheels	0:1193dbfe28e2	283	// next.
pwheels	0:1193dbfe28e2	284	//
pwheels	0:1193dbfe28e2	285	void owFamilySearchSetup(int portnum, SMALLINT search_family)
pwheels	0:1193dbfe28e2	286	{
pwheels	0:1193dbfe28e2	287	uchar i;
pwheels	0:1193dbfe28e2	288
pwheels	0:1193dbfe28e2	289	// set the search state to find SearchFamily type devices
pwheels	0:1193dbfe28e2	290	SerialNum[portnum][0] = search_family;
pwheels	0:1193dbfe28e2	291	for (i = 1; i < 8; i++)
pwheels	0:1193dbfe28e2	292	SerialNum[portnum][i] = 0;
pwheels	0:1193dbfe28e2	293	LastDiscrepancy[portnum] = 64;
pwheels	0:1193dbfe28e2	294	LastDevice[portnum] = FALSE;
pwheels	0:1193dbfe28e2	295	}
pwheels	0:1193dbfe28e2	296
pwheels	0:1193dbfe28e2	297	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	298	// Set the current search state to skip the current family code.
pwheels	0:1193dbfe28e2	299	//
pwheels	0:1193dbfe28e2	300	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	301	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	302	//
pwheels	0:1193dbfe28e2	303	void owSkipFamily(int portnum)
pwheels	0:1193dbfe28e2	304	{
pwheels	0:1193dbfe28e2	305	// set the Last discrepancy to last family discrepancy
pwheels	0:1193dbfe28e2	306	LastDiscrepancy[portnum] = LastFamilyDiscrepancy[portnum];
pwheels	0:1193dbfe28e2	307	LastFamilyDiscrepancy[portnum] = 0;
pwheels	0:1193dbfe28e2	308
pwheels	0:1193dbfe28e2	309	// check for end of list
pwheels	0:1193dbfe28e2	310	if (LastDiscrepancy[portnum] == 0)
pwheels	0:1193dbfe28e2	311	LastDevice[portnum] = TRUE;
pwheels	0:1193dbfe28e2	312	}
pwheels	0:1193dbfe28e2	313
pwheels	0:1193dbfe28e2	314	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	315	// The 'owAccess' function resets the 1-Wire and sends a MATCH Serial
pwheels	0:1193dbfe28e2	316	// Number command followed by the current SerialNum code. After this
pwheels	0:1193dbfe28e2	317	// function is complete the 1-Wire device is ready to accept device-specific
pwheels	0:1193dbfe28e2	318	// commands.
pwheels	0:1193dbfe28e2	319	//
pwheels	0:1193dbfe28e2	320	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	321	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	322	//
pwheels	0:1193dbfe28e2	323	// Returns: TRUE (1) : reset indicates present and device is ready
pwheels	0:1193dbfe28e2	324	// for commands.
pwheels	0:1193dbfe28e2	325	// FALSE (0): reset does not indicate presence or echos 'writes'
pwheels	0:1193dbfe28e2	326	// are not correct.
pwheels	0:1193dbfe28e2	327	//
pwheels	0:1193dbfe28e2	328	SMALLINT owAccess(int portnum)
pwheels	0:1193dbfe28e2	329	{
pwheels	0:1193dbfe28e2	330	uchar sendpacket[9];
pwheels	0:1193dbfe28e2	331	uchar i;
pwheels	0:1193dbfe28e2	332
pwheels	0:1193dbfe28e2	333	// reset the 1-wire
pwheels	0:1193dbfe28e2	334	if (owTouchReset(portnum))
pwheels	0:1193dbfe28e2	335	{
pwheels	0:1193dbfe28e2	336	// create a buffer to use with block function
pwheels	0:1193dbfe28e2	337	// match Serial Number command 0x55
pwheels	0:1193dbfe28e2	338	sendpacket[0] = 0x55;
pwheels	0:1193dbfe28e2	339	// Serial Number
pwheels	0:1193dbfe28e2	340	for (i = 1; i < 9; i++)
pwheels	0:1193dbfe28e2	341	sendpacket[i] = SerialNum[portnum][i-1];
pwheels	0:1193dbfe28e2	342
pwheels	0:1193dbfe28e2	343	// send/recieve the transfer buffer
pwheels	0:1193dbfe28e2	344	if (owBlock(portnum,FALSE,sendpacket,9))
pwheels	0:1193dbfe28e2	345	{
pwheels	0:1193dbfe28e2	346	// verify that the echo of the writes was correct
pwheels	0:1193dbfe28e2	347	for (i = 1; i < 9; i++)
pwheels	0:1193dbfe28e2	348	if (sendpacket[i] != SerialNum[portnum][i-1])
pwheels	0:1193dbfe28e2	349	return FALSE;
pwheels	0:1193dbfe28e2	350	if (sendpacket[0] != 0x55)
pwheels	0:1193dbfe28e2	351	{
pwheels	0:1193dbfe28e2	352	OWERROR(OWERROR_WRITE_VERIFY_FAILED);
pwheels	0:1193dbfe28e2	353	return FALSE;
pwheels	0:1193dbfe28e2	354	}
pwheels	0:1193dbfe28e2	355	else
pwheels	0:1193dbfe28e2	356	return TRUE;
pwheels	0:1193dbfe28e2	357	}
pwheels	0:1193dbfe28e2	358	else
pwheels	0:1193dbfe28e2	359	OWERROR(OWERROR_BLOCK_FAILED);
pwheels	0:1193dbfe28e2	360	}
pwheels	0:1193dbfe28e2	361	else
pwheels	0:1193dbfe28e2	362	OWERROR(OWERROR_NO_DEVICES_ON_NET);
pwheels	0:1193dbfe28e2	363
pwheels	0:1193dbfe28e2	364	// reset or match echo failed
pwheels	0:1193dbfe28e2	365	return FALSE;
pwheels	0:1193dbfe28e2	366	}
pwheels	0:1193dbfe28e2	367
pwheels	0:1193dbfe28e2	368	//----------------------------------------------------------------------
pwheels	0:1193dbfe28e2	369	// The function 'owVerify' verifies that the current device
pwheels	0:1193dbfe28e2	370	// is in contact with the 1-Wire Net.
pwheels	0:1193dbfe28e2	371	// Using the find alarm command 0xEC will verify that the device
pwheels	0:1193dbfe28e2	372	// is in contact with the 1-Wire Net and is in an 'alarm' state.
pwheels	0:1193dbfe28e2	373	//
pwheels	0:1193dbfe28e2	374	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	375	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	376	// 'alarm_only' - TRUE (1) the find alarm command 0xEC
pwheels	0:1193dbfe28e2	377	// is sent instead of the normal search
pwheels	0:1193dbfe28e2	378	// command 0xF0.
pwheels	0:1193dbfe28e2	379	//
pwheels	0:1193dbfe28e2	380	// Returns: TRUE (1) : when the 1-Wire device was verified
pwheels	0:1193dbfe28e2	381	// to be on the 1-Wire Net
pwheels	0:1193dbfe28e2	382	// with alarm_only == FALSE
pwheels	0:1193dbfe28e2	383	// or verified to be on the 1-Wire Net
pwheels	0:1193dbfe28e2	384	// AND in an alarm state when
pwheels	0:1193dbfe28e2	385	// alarm_only == TRUE.
pwheels	0:1193dbfe28e2	386	// FALSE (0): the 1-Wire device was not on the
pwheels	0:1193dbfe28e2	387	// 1-Wire Net or if alarm_only
pwheels	0:1193dbfe28e2	388	// == TRUE, the device may be on the
pwheels	0:1193dbfe28e2	389	// 1-Wire Net but in a non-alarm state.
pwheels	0:1193dbfe28e2	390	//
pwheels	0:1193dbfe28e2	391	SMALLINT owVerify(int portnum, SMALLINT alarm_only)
pwheels	0:1193dbfe28e2	392	{
pwheels	0:1193dbfe28e2	393	uchar i,sendlen=0,goodbits=0,cnt=0,s,tst;
pwheels	0:1193dbfe28e2	394	uchar sendpacket[50];
pwheels	0:1193dbfe28e2	395
pwheels	0:1193dbfe28e2	396	// construct the search
pwheels	0:1193dbfe28e2	397	if (alarm_only)
pwheels	0:1193dbfe28e2	398	sendpacket[sendlen++] = 0xEC; // issue the alarming search command
pwheels	0:1193dbfe28e2	399	else
pwheels	0:1193dbfe28e2	400	sendpacket[sendlen++] = 0xF0; // issue the search command
pwheels	0:1193dbfe28e2	401	// set all bits at first
pwheels	0:1193dbfe28e2	402	for (i = 1; i <= 24; i++)
pwheels	0:1193dbfe28e2	403	sendpacket[sendlen++] = 0xFF;
pwheels	0:1193dbfe28e2	404	// now set or clear apropriate bits for search
pwheels	0:1193dbfe28e2	405	for (i = 0; i < 64; i++)
pwheels	0:1193dbfe28e2	406	bitacc(WRITE_FUNCTION,bitacc(READ_FUNCTION,0,i,&SerialNum[portnum][0]),(int)((i+1)*3-1),&sendpacket[1]);
pwheels	0:1193dbfe28e2	407
pwheels	0:1193dbfe28e2	408	// send/recieve the transfer buffer
pwheels	0:1193dbfe28e2	409	if (owBlock(portnum,TRUE,sendpacket,sendlen))
pwheels	0:1193dbfe28e2	410	{
pwheels	0:1193dbfe28e2	411	// check results to see if it was a success
pwheels	0:1193dbfe28e2	412	for (i = 0; i < 192; i += 3)
pwheels	0:1193dbfe28e2	413	{
pwheels	0:1193dbfe28e2	414	tst = (bitacc(READ_FUNCTION,0,i,&sendpacket[1]) << 1) \|
pwheels	0:1193dbfe28e2	415	bitacc(READ_FUNCTION,0,(int)(i+1),&sendpacket[1]);
pwheels	0:1193dbfe28e2	416
pwheels	0:1193dbfe28e2	417	s = bitacc(READ_FUNCTION,0,cnt++,&SerialNum[portnum][0]);
pwheels	0:1193dbfe28e2	418
pwheels	0:1193dbfe28e2	419	if (tst == 0x03) // no device on line
pwheels	0:1193dbfe28e2	420	{
pwheels	0:1193dbfe28e2	421	goodbits = 0; // number of good bits set to zero
pwheels	0:1193dbfe28e2	422	break; // quit
pwheels	0:1193dbfe28e2	423	}
pwheels	0:1193dbfe28e2	424
pwheels	0:1193dbfe28e2	425	if (((s == 0x01) && (tst == 0x02)) \|\|
pwheels	0:1193dbfe28e2	426	((s == 0x00) && (tst == 0x01)) ) // correct bit
pwheels	0:1193dbfe28e2	427	goodbits++; // count as a good bit
pwheels	0:1193dbfe28e2	428	}
pwheels	0:1193dbfe28e2	429
pwheels	0:1193dbfe28e2	430	// check too see if there were enough good bits to be successful
pwheels	0:1193dbfe28e2	431	if (goodbits >= 8)
pwheels	0:1193dbfe28e2	432	return TRUE;
pwheels	0:1193dbfe28e2	433	}
pwheels	0:1193dbfe28e2	434	else
pwheels	0:1193dbfe28e2	435	OWERROR(OWERROR_BLOCK_FAILED);
pwheels	0:1193dbfe28e2	436
pwheels	0:1193dbfe28e2	437	// block fail or device not present
pwheels	0:1193dbfe28e2	438	return FALSE;
pwheels	0:1193dbfe28e2	439	}
pwheels	0:1193dbfe28e2	440
pwheels	0:1193dbfe28e2	441	//----------------------------------------------------------------------
pwheels	0:1193dbfe28e2	442	// Perform a overdrive MATCH command to select the 1-Wire device with
pwheels	0:1193dbfe28e2	443	// the address in the ID data register.
pwheels	0:1193dbfe28e2	444	//
pwheels	0:1193dbfe28e2	445	// 'portnum' - number 0 to MAX_PORTNUM-1. This number is provided to
pwheels	0:1193dbfe28e2	446	// indicate the symbolic port number.
pwheels	0:1193dbfe28e2	447	//
pwheels	0:1193dbfe28e2	448	// Returns: TRUE: If the device is present on the 1-Wire Net and
pwheels	0:1193dbfe28e2	449	// can do overdrive then the device is selected.
pwheels	0:1193dbfe28e2	450	// FALSE: Device is not present or not capable of overdrive.
pwheels	0:1193dbfe28e2	451	//
pwheels	0:1193dbfe28e2	452	// *Note: This function could be converted to send DS2480
pwheels	0:1193dbfe28e2	453	// commands in one packet.
pwheels	0:1193dbfe28e2	454	//
pwheels	0:1193dbfe28e2	455	SMALLINT owOverdriveAccess(int portnum)
pwheels	0:1193dbfe28e2	456	{
pwheels	0:1193dbfe28e2	457	uchar sendpacket[8];
pwheels	0:1193dbfe28e2	458	uchar i, bad_echo = FALSE;
pwheels	0:1193dbfe28e2	459
pwheels	0:1193dbfe28e2	460	// make sure normal level
pwheels	0:1193dbfe28e2	461	owLevel(portnum,MODE_NORMAL);
pwheels	0:1193dbfe28e2	462
pwheels	0:1193dbfe28e2	463	// force to normal communication speed
pwheels	0:1193dbfe28e2	464	owSpeed(portnum,MODE_NORMAL);
pwheels	0:1193dbfe28e2	465
pwheels	0:1193dbfe28e2	466	// call the 1-Wire Net reset function
pwheels	0:1193dbfe28e2	467	if (owTouchReset(portnum))
pwheels	0:1193dbfe28e2	468	{
pwheels	0:1193dbfe28e2	469	// send the match command 0x69
pwheels	0:1193dbfe28e2	470	if (owWriteByte(portnum,0x69))
pwheels	0:1193dbfe28e2	471	{
pwheels	0:1193dbfe28e2	472	// switch to overdrive communication speed
pwheels	0:1193dbfe28e2	473	owSpeed(portnum,MODE_OVERDRIVE);
pwheels	0:1193dbfe28e2	474
pwheels	0:1193dbfe28e2	475	// create a buffer to use with block function
pwheels	0:1193dbfe28e2	476	// Serial Number
pwheels	0:1193dbfe28e2	477	for (i = 0; i < 8; i++)
pwheels	0:1193dbfe28e2	478	sendpacket[i] = SerialNum[portnum][i];
pwheels	0:1193dbfe28e2	479
pwheels	0:1193dbfe28e2	480	// send/recieve the transfer buffer
pwheels	0:1193dbfe28e2	481	if (owBlock(portnum,FALSE,sendpacket,8))
pwheels	0:1193dbfe28e2	482	{
pwheels	0:1193dbfe28e2	483	// verify that the echo of the writes was correct
pwheels	0:1193dbfe28e2	484	for (i = 0; i < 8; i++)
pwheels	0:1193dbfe28e2	485	if (sendpacket[i] != SerialNum[portnum][i])
pwheels	0:1193dbfe28e2	486	bad_echo = TRUE;
pwheels	0:1193dbfe28e2	487	// if echo ok then success
pwheels	0:1193dbfe28e2	488	if (!bad_echo)
pwheels	0:1193dbfe28e2	489	return TRUE;
pwheels	0:1193dbfe28e2	490	else
pwheels	0:1193dbfe28e2	491	OWERROR(OWERROR_WRITE_VERIFY_FAILED);
pwheels	0:1193dbfe28e2	492	}
pwheels	0:1193dbfe28e2	493	else
pwheels	0:1193dbfe28e2	494	OWERROR(OWERROR_BLOCK_FAILED);
pwheels	0:1193dbfe28e2	495	}
pwheels	0:1193dbfe28e2	496	else
pwheels	0:1193dbfe28e2	497	OWERROR(OWERROR_WRITE_BYTE_FAILED);
pwheels	0:1193dbfe28e2	498	}
pwheels	0:1193dbfe28e2	499	else
pwheels	0:1193dbfe28e2	500	OWERROR(OWERROR_NO_DEVICES_ON_NET);
pwheels	0:1193dbfe28e2	501
pwheels	0:1193dbfe28e2	502	// failure, force back to normal communication speed
pwheels	0:1193dbfe28e2	503	owSpeed(portnum,MODE_NORMAL);
pwheels	0:1193dbfe28e2	504
pwheels	0:1193dbfe28e2	505	return FALSE;
pwheels	0:1193dbfe28e2	506	}
pwheels	0:1193dbfe28e2	507
pwheels	0:1193dbfe28e2	508	//--------------------------------------------------------------------------
pwheels	0:1193dbfe28e2	509	// Bit utility to read and write a bit in the buffer 'buf'.
pwheels	0:1193dbfe28e2	510	//
pwheels	0:1193dbfe28e2	511	// 'op' - operation (1) to set and (0) to read
pwheels	0:1193dbfe28e2	512	// 'state' - set (1) or clear (0) if operation is write (1)
pwheels	0:1193dbfe28e2	513	// 'loc' - bit number location to read or write
pwheels	0:1193dbfe28e2	514	// 'buf' - pointer to array of bytes that contains the bit
pwheels	0:1193dbfe28e2	515	// to read or write
pwheels	0:1193dbfe28e2	516	//
pwheels	0:1193dbfe28e2	517	// Returns: 1 if operation is set (1)
pwheels	0:1193dbfe28e2	518	// 0/1 state of bit number 'loc' if operation is reading
pwheels	0:1193dbfe28e2	519	//
pwheels	0:1193dbfe28e2	520	SMALLINT bitacc(SMALLINT op, SMALLINT state, SMALLINT loc, uchar *buf)
pwheels	0:1193dbfe28e2	521	{
pwheels	0:1193dbfe28e2	522	SMALLINT nbyt,nbit;
pwheels	0:1193dbfe28e2	523
pwheels	0:1193dbfe28e2	524	nbyt = (loc / 8);
pwheels	0:1193dbfe28e2	525	nbit = loc - (nbyt * 8);
pwheels	0:1193dbfe28e2	526
pwheels	0:1193dbfe28e2	527	if (op == WRITE_FUNCTION)
pwheels	0:1193dbfe28e2	528	{
pwheels	0:1193dbfe28e2	529	if (state)
pwheels	0:1193dbfe28e2	530	buf[nbyt] \|= (0x01 << nbit);
pwheels	0:1193dbfe28e2	531	else
pwheels	0:1193dbfe28e2	532	buf[nbyt] &= ~(0x01 << nbit);
pwheels	0:1193dbfe28e2	533
pwheels	0:1193dbfe28e2	534	return 1;
pwheels	0:1193dbfe28e2	535	}
pwheels	0:1193dbfe28e2	536	else
pwheels	0:1193dbfe28e2	537	return ((buf[nbyt] >> nbit) & 0x01);
pwheels	0:1193dbfe28e2	538	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	24 Mar 2011
Imports:	104
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	6

ownet.cpp@0:1193dbfe28e2, 2011-03-24 (annotated)

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