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Comitter:
mauuuuul
Date:
Wed Aug 26 19:44:50 2020 +0000
Parent:
13:016b84669050
Commit message:
zzzz

Changed in this revision

OneWire.cpp Show diff for this revision Revisions of this file
OneWire.h Show diff for this revision Revisions of this file
iButton.cpp Show annotated file Show diff for this revision Revisions of this file
iButton.h Show annotated file Show diff for this revision Revisions of this file
--- a/OneWire.cpp	Thu Apr 04 20:46:58 2019 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,506 +0,0 @@
-/*
-Copyright (c) 2007, Jim Studt  (original old version - many contributors since)
-
-The latest version of this library may be found at:
-  http://www.pjrc.com/teensy/td_libs_Onehtml
-
-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 One  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-  Delete very old, out-of-date readme file (info is here)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_Onehtml
-  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"
-
-
-/**
- * @brief   Constructs a OneWire object.
- * @note    GPIO is configured as output and an internal pull up resistor is connected.
- *          But because for STM chips it takes very long time to change from output
- *          to input an open drain mode is used rather and the GPIO remains output forever.
- * @param
- * @retval
- */
-OneWire::OneWire(PinName pin) :
-    DigitalInOut(pin)
-{
-    MODE(); // set mode to either OpenDrain for STM or PullUp for others
-    INIT_WAIT;
-#if ONEWIRE_SEARCH
-    reset_search();
-#endif
-}
-
-/**
- * @brief   Performs the onewire reset function.
- * @note    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;
- * @param
- * @retval  1 if a device asserted a presence pulse, 0 otherwise.
- */
-uint8_t OneWire::reset(void)
-{
-    uint8_t present;
-
-    OUTPUT();
-    WRITE(0);           // pull down the 1-wire bus do create reset pulse
-    WAIT_US(500);       // wait at least 480 us
-    INPUT();            // release the 1-wire bus and go into receive mode
-    WAIT_US(90);        // DS1820 waits about 15 to 60 us and generates a 60 to 240 us presence pulse
-    present = !READ();  // read the presence pulse
-    WAIT_US(420);
-    
-    return present;
-}
-
-/**
- * @brief   Writes a bit.
- * @note    GPIO registers are used for STM chips to cut time.
- * @param
- * @retval
- */
-void OneWire::write_bit(uint8_t v)
-{
-    OUTPUT();
-    if (v & 1) {
-        WRITE(0);   // drive output low
-        WAIT_US(1);
-        WRITE(1);   // drive output high
-        WAIT_US(60);
-    }
-    else {
-        WRITE(0);   // drive output low
-        WAIT_US(60);
-        WRITE(1);   // drive output high
-        WAIT_US(1);
-    }
-}
-
-/**
- * @brief   Reads a bit.
- * @note    GPIO registers are used for STM chips to cut time.
- * @param
- * @retval
- */
-uint8_t OneWire::read_bit(void)
-{
-    const int SAMPLE_POINT = 10;
-    uint8_t r;
-    int     t;
-
-    OUTPUT();
-    WRITE(0);
-    timer.start();
-    INPUT();
-    t = timer.read_us();
-    if (t < SAMPLE_POINT)
-        WAIT_US(SAMPLE_POINT - t);
-    r = READ();
-    timer.stop();
-    timer.reset();
-    WAIT_US(55);
-    //printf("t = %d\r\n", t);
-    return r;
-}
-
-/**
- * @brief   Writes a byte.
- * @note    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.
- * @param
- * @retval
- */
-void OneWire::write_byte(uint8_t v, uint8_t power /* = 0 */ )
-{
-    uint8_t bitMask;
-
-    for (bitMask = 0x01; bitMask; bitMask <<= 1)
-        write_bit((bitMask & v) ? 1 : 0);
-    if (!power)
-        INPUT();
-}
-
-/**
- * @brief   Writes bytes.
- * @note
- * @param
- * @retval
- */
-void OneWire::write_bytes(const uint8_t* buf, uint16_t count, bool power /* = 0 */ )
-{
-    for (uint16_t i = 0; i < count; i++)
-        write_byte(buf[i]);
-    if (!power)
-        INPUT();
-}
-
-/**
- * @brief   Reads a byte.
- * @note
- * @param
- * @retval
- */
-uint8_t OneWire::read_byte()
-{
-    uint8_t bitMask;
-    uint8_t r = 0;
-
-    for (bitMask = 0x01; bitMask; bitMask <<= 1) {
-        if (read_bit())
-            r |= bitMask;
-    }
-
-    return r;
-}
-
-/**
- * @brief   Reads bytes.
- * @note
- * @param
- * @retval
- */
-void OneWire::read_bytes(uint8_t* buf, uint16_t count)
-{
-    for (uint16_t i = 0; i < count; i++)
-        buf[i] = read_byte();
-}
-
-/**
- * @brief   Selects ROM.
- * @note
- * @param
- * @retval
- */
-void OneWire::select(const uint8_t rom[8])
-{
-    uint8_t i;
-
-    write_byte(0x55);   // Choose ROM
-    for (i = 0; i < 8; i++)
-        write_byte(rom[i]);
-}
-
-/**
- * @brief   Skips ROM select.
- * @note
- * @param
- * @retval
- */
-void OneWire::skip()
-{
-    write_byte(0xCC);   // Skip ROM
-}
-
-/**
- * @brief   Unpowers the chip.
- * @note
- * @param
- * @retval
- */
-void OneWire::depower()
-{
-    INPUT();
-}
-
-#if ONEWIRE_SEARCH
-//
-
-/**
- * @brief   Resets the search state.
- * @note    We need to use this function to start a search again from the beginning.
- *          We do not need to do it for the first search, though we could.
- * @param
- * @retval
- */
-void OneWire::reset_search()
-{
-    // reset the search state
-    LastDiscrepancy = 0;
-    LastDeviceFlag = false;
-    LastFamilyDiscrepancy = 0;
-    for (int i = 7;; i--) {
-        ROM_NO[i] = 0;
-        if (i == 0)
-            break;
-    }
-}
-
-/**
- * @brief   Sets the search state to find SearchFamily type devices.
- * @note
- * @param
- * @retval
- */
-void OneWire::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;
-    LastDiscrepancy = 64;
-    LastFamilyDiscrepancy = 0;
-    LastDeviceFlag = false;
-}
-
-/**
- * @brief   Performs a search.
- * @note    Perform a search. If this function returns a '1' then it has
-            enumerated the next device and you may retrieve the ROM from the
-            OneWire::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 OneWire::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.
- * @param
- * @retval  true  : device found, ROM number in ROM_NO buffer
- *          false : device not found, end of search
- */
-uint8_t OneWire::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 (!LastDeviceFlag) {
-        // 1-Wire reset
-        if (!reset()) {
-            // reset the search
-            LastDiscrepancy = 0;
-            LastDeviceFlag = false;
-            LastFamilyDiscrepancy = 0;
-            return false;
-        }
-
-        // issue the search command
-        write_byte(0xF0);
-
-        // loop to do the search
-        do {
-            // read a bit and its complement
-            id_bit = read_bit();
-            cmp_id_bit = 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 < 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 == 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)
-                            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
-                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 LastDiscrepancy,LastDeviceFlag,search_result
-            LastDiscrepancy = last_zero;
-
-            // check for last device
-            if (LastDiscrepancy == 0)
-                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]) {
-        LastDiscrepancy = 0;
-        LastDeviceFlag = false;
-        LastFamilyDiscrepancy = 0;
-        search_result = false;
-    }
-
-    for (int i = 0; i < 8; i++)
-        newAddr[i] = ROM_NO[i];
-    return search_result;
-}
-#endif
-//
-#if ONEWIRE_CRC
-//
-/**
- * @brief   Computes a Dallas Semiconductor 8 bit CRC directly.
- * @note    The 1-Wire CRC scheme is described in Maxim Application Note 27:
-            "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products"
- * @param
- * @retval
- */
-uint8_t OneWire::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
--- a/OneWire.h	Thu Apr 04 20:46:58 2019 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,189 +0,0 @@
-#ifndef OneWire_h
-#define OneWire_h
-
-#include <inttypes.h>
-#include <mbed.h>
-
-#if defined(TARGET_STM)
-    #define MODE()      output(); \
-                        mode(OpenDrain)
-    #define OUTPUT()    // configured as output in the constructor and stays like that forever
-#if defined(TARGET_STM32L072xx)
-    #define PORT        ((GPIO_TypeDef *)(GPIOA_BASE + 0x0400 * STM_PORT(gpio.pin)))
-    #define PINMASK     (1 << STM_PIN(gpio.pin))
-    #define INPUT()     (PORT->MODER &= ~(GPIO_MODER_MODE0_0 << (STM_PIN(gpio.pin) * 2)))                              
-    #define READ()      ((PORT->IDR & gpio.mask) != 0)
-    #define WRITE(x)    (x == 1 ? PORT->BSRR = PINMASK : PORT->BRR = PINMASK)
-#else
-    #define INPUT()     (*gpio.reg_set = gpio.mask) // write 1 to open drain
-    #define READ()      ((*gpio.reg_in & gpio.mask) != 0)
-    #define WRITE(x)    write(x)
-#endif
-#else
-    #define MODE()      mode(PullUp)
-    #define INPUT()     input()
-    #define OUTPUT()    output()
-    #define READ()      read()
-    #define WRITE(x)    write(x)
-#endif
-
-#ifdef TARGET_NORDIC
-//NORDIC targets (NRF) use software delays since their ticker uses a 32kHz clock
-    static uint32_t loops_per_us = 0;
-    
-    #define INIT_WAIT   init_soft_delay()
-    #define WAIT_US(x)  for(int cnt = 0; cnt < (x * loops_per_us) >> 5; cnt++) {__NOP(); __NOP(); __NOP();}
-    
-void init_soft_delay( void ) {
-    if (loops_per_us == 0) {
-        loops_per_us = 1;
-        Timer timey; 
-        timey.start();
-        ONEWIRE_DELAY_US(320000);                     
-        timey.stop();
-        loops_per_us = (320000 + timey.read_us() / 2) / timey.read_us();  
-    }
-}
-#else
-    #define INIT_WAIT
-    #define WAIT_US(x)  wait_us(x)
-#endif
-
-// You can exclude certain features from OneWire.  In theory, this
-// might save some space.  In practice, the compiler automatically
-// removes unused code (technically, the linker, using -fdata-sections
-// and -ffunction-sections when compiling, and Wl,--gc-sections
-// when linking), so most of these will not result in any code size
-// reduction.  Well, unless you try to use the missing features
-// and redesign your program to not need them!  ONEWIRE_CRC8_TABLE
-// is the exception, because it selects a fast but large algorithm
-// or a small but slow algorithm.
-
-// you can exclude onewire_search by defining that to 0
-#ifndef ONEWIRE_SEARCH
-#define ONEWIRE_SEARCH 1
-#endif
-
-// You can exclude CRC checks altogether by defining this to 0
-#ifndef ONEWIRE_CRC
-#define ONEWIRE_CRC 1
-#endif
-
-class OneWire : public DigitalInOut
-{
-    Timer timer;
-
-#if ONEWIRE_SEARCH
-    // global search state
-    unsigned char ROM_NO[8];
-    uint8_t LastDiscrepancy;
-    uint8_t LastFamilyDiscrepancy;
-    uint8_t LastDeviceFlag;
-#endif
-
-public:
-    OneWire(PinName pin);
-
-    // Perform a 1-Wire reset cycle. Returns 1 if a device responds
-    // with a presence pulse.  Returns 0 if there is no device or the
-    // bus is shorted or otherwise held low for more than 250uS
-    uint8_t reset(void);
-
-    // Issue a 1-Wire rom select command, you do the reset first.
-    void select(const uint8_t rom[8]);
-
-    // Issue a 1-Wire rom skip command, to address all on bus.
-    void skip(void);
-
-    // Write a byte. If 'power' is one then the wire is held high at
-    // the end for parasitically powered devices. You are responsible
-    // for eventually depowering it by calling depower() or doing
-    // another read or write.
-    void write_byte(uint8_t v, uint8_t power = 0);
-
-    void write_bytes(const uint8_t *buf, uint16_t count, bool power = 0);
-
-    // Read a byte.
-    uint8_t read_byte(void);
-
-    void read_bytes(uint8_t *buf, uint16_t count);
-
-    // Write a bit. The bus is always left powered at the end, see
-    // note in write() about that.
-    void write_bit(uint8_t v);
-
-    // Read a bit.
-    uint8_t read_bit(void);
-
-    // Stop forcing power onto the bus. You only need to do this if
-    // you used the 'power' flag to write() or used a write_bit() call
-    // and aren't about to do another read or write. You would rather
-    // not leave this powered if you don't have to, just in case
-    // someone shorts your bus.
-    void depower(void);
-
-#if ONEWIRE_SEARCH
-    // Clear the search state so that if will start from the beginning again.
-    void reset_search();
-
-    // Setup the search to find the device type 'family_code' on the next call
-    // to search(*newAddr) if it is present.
-    void target_search(uint8_t family_code);
-
-    // Look for the next device. Returns 1 if a new address has been
-    // returned. A zero might mean that the bus is shorted, there are
-    // no devices, or you have already retrieved all of them.  It
-    // might be a good idea to check the CRC to make sure you didn't
-    // get garbage.  The order is deterministic. You will always get
-    // the same devices in the same order.
-    uint8_t search(uint8_t *newAddr);
-#endif
-
-#if ONEWIRE_CRC
-    // Compute a Dallas Semiconductor 8 bit CRC, these are used in the
-    // ROM and scratchpad registers.
-    static uint8_t crc8(const uint8_t *addr, uint8_t len);
-
-#if ONEWIRE_CRC16
-    // Compute the 1-Wire CRC16 and compare it against the received CRC.
-    // Example usage (reading a DS2408):
-    //    // Put everything in a buffer so we can compute the CRC easily.
-    //    uint8_t buf[13];
-    //    buf[0] = 0xF0;    // Read PIO Registers
-    //    buf[1] = 0x88;    // LSB address
-    //    buf[2] = 0x00;    // MSB address
-    //    WriteBytes(net, buf, 3);    // Write 3 cmd bytes
-    //    ReadBytes(net, buf+3, 10);  // Read 6 data bytes, 2 0xFF, 2 CRC16
-    //    if (!CheckCRC16(buf, 11, &buf[11])) {
-    //        // Handle error.
-    //    }     
-    //          
-    // @param input - Array of bytes to checksum.
-    // @param len - How many bytes to use.
-    // @param inverted_crc - The two CRC16 bytes in the received data.
-    //                       This should just point into the received data,
-    //                       *not* at a 16-bit integer.
-    // @param crc - The crc starting value (optional)
-    // @return True, iff the CRC matches.
-    static bool check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc = 0);
-
-    // Compute a Dallas Semiconductor 16 bit CRC.  This is required to check
-    // the integrity of data received from many 1-Wire devices.  Note that the
-    // CRC computed here is *not* what you'll get from the 1-Wire network,
-    // for two reasons:
-    //   1) The CRC is transmitted bitwise inverted.
-    //   2) Depending on the endian-ness of your processor, the binary
-    //      representation of the two-byte return value may have a different
-    //      byte order than the two bytes you get from 1-Wire.
-    // @param input - Array of bytes to checksum.
-    // @param len - How many bytes to use.
-    // @param crc - The crc starting value (optional)
-    // @return The CRC16, as defined by Dallas Semiconductor.
-    static uint16_t crc16(const uint8_t* input, uint16_t len, uint16_t crc = 0);
-#endif
-#endif
-};
-
-#endif
-
-            
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/iButton.cpp	Wed Aug 26 19:44:50 2020 +0000
@@ -0,0 +1,141 @@
+#include "iButton.h"
+
+extern Serial dbg;
+
+iButton::iButton(PinName IO) : io(IO)
+{
+}
+
+iButton::~iButton()
+{
+}
+
+void iButton::OneWireReset(void)
+{
+    io.output();
+    io = 0;
+    wait_us(500);
+    io.input();
+    wait_us(500);
+}
+
+void iButton::OneWireOutByte(unsigned char data)
+{
+    for (int n = 8;n!=0; n--)
+    {
+        if ((data & 0x01) == 1)
+        {
+            io.output();
+            io = 0;
+            wait_us(5);
+            io.input();
+            wait_us(60);
+        }
+        else 
+        {
+            io.output();
+            wait_us(60);
+            io.input();
+        }
+        data = data >> 1;
+    }
+}
+
+unsigned char iButton::OneWireReadByte(void)
+{
+    unsigned char d = 0;
+    unsigned char b;
+    for (int n = 0; n<8; n++)
+    {
+        io.output();
+        io = 0;
+        wait_us(5);
+        io.input();
+        wait_us(5);
+        b = io;
+        wait_us(50);
+        d = (d >> 1) | (b << 7);
+    }
+    return d;
+}
+
+void iButton::ResetData()
+{
+    detect.family = 0;
+    detect.serial.clear();
+    detect.crc = 0;
+    detect.valid = false;
+}
+
+void iButton::DetectiButton(void)
+{
+    unsigned char crc = 0;
+    
+    OneWireReset();
+    OneWireOutByte(0x33);
+    
+    ResetData();
+    
+    detect.family = OneWireReadByte();
+    crc = crc8(crc, detect.family);
+    if (detect.family == 0x00 || detect.family == 0xFF)
+    {
+        detect.valid = false;
+        return;
+    }
+    
+    for (int i = 0; i <6; i++)
+    {
+//        detect.serial[i] = OneWireReadByte();
+        detect.serial.push_back(OneWireReadByte());
+        crc = crc8(crc, detect.serial[i]);
+    }
+    detect.crc = OneWireReadByte();
+    if (crc == detect.crc)
+    {
+        detect.valid = true;
+    }
+    //dbg.printf("[Detect Ibutton]\r\n");
+    return;
+}
+
+std::string conv(const unsigned char &val)
+{
+    char st[5];
+    sprintf(st,"%02X",val);
+    return st;
+}
+
+bool iButton::IsTaping(void)
+{
+    return detect.valid;
+}
+
+std::string iButton::GetData(void)
+{
+    size_t sz = detect.serial.size();
+    string ret = "";
+    
+    for(int i=sz-1; i>=0; i--)
+    {
+        ret += conv(detect.serial[i]);
+    }
+    return ret;
+}
+
+unsigned char iButton::crc8(unsigned char crc, unsigned char data)
+{
+    crc = crc ^ data;
+    for (int i = 0; i < 8; i++)
+    {
+        if (crc & 0x01)
+        {
+            crc = (crc >> 1) ^ 0x8C; 
+        }
+        else
+        {
+            crc >>= 1; 
+        }
+    }
+    return crc;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/iButton.h	Wed Aug 26 19:44:50 2020 +0000
@@ -0,0 +1,48 @@
+#ifndef I_BUTTON_H
+#define I_BUTTON_H
+
+#include "mbed.h"
+#include <string>
+#include <vector>
+
+//typedef struct
+//{
+//    unsigned char family;
+//    unsigned char serial[6];
+//    unsigned char crc;
+//    unsigned char valid;
+//} ibuttonvalue;
+class ibuttonvalue
+{
+public:
+    unsigned char family;
+    std::vector<unsigned char> serial;
+    unsigned char crc;
+    bool valid;
+};
+
+class iButton
+{
+public:
+    
+    iButton(PinName IO);
+    ~iButton();
+    
+    void OneWireReset(void);
+    void OneWireOutByte(unsigned char data);
+    unsigned char OneWireReadByte(void);
+    void DetectiButton(void);
+    std::string GetData(void);
+    bool IsTaping(void);
+    
+private:
+    DigitalInOut io;    
+    ibuttonvalue detect;
+    unsigned char CrcTemp;
+    
+    unsigned char crc8(unsigned char crc, unsigned char data);
+    void ResetData();
+    
+};
+
+#endif // I_BUTTON_H