Revision 0:5530bf2d0e94, committed 2019-01-23

Comitter:

croberts21

Date:

Wed Jan 23 23:44:57 2019 +0000

Commit message:

All files added

Changed in this revision

diff -r 000000000000 -r 5530bf2d0e94 LinkedList.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LinkedList.cpp	Wed Jan 23 23:44:57 2019 +0000
@@ -0,0 +1,194 @@
+/**
+ * @file    LinkedList.cpp
+ * @brief   Core Utility - Templated Linked List class
+ * @author  sam grove
+ * @version 1.0
+ * @see     
+ *
+ * Copyright (c) 2013
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LinkedList.h"    // api wrapper
+
+template<class retT>
+LinkedList<retT>::LinkedList()
+{
+    // clear the member
+    _head = 0;
+
+    return;
+}
+
+template<class retT>
+LinkedList<retT>::~LinkedList()
+{
+    // free any memory that is on the heap
+    while(remove(1) != NULL);
+
+    return;
+}
+
+template<class retT>
+retT *LinkedList<retT>::push(void *data)
+{
+    retT *new_node = new retT [1];
+    // make sure the new object was allocated
+    if (0 == new_node)
+    {
+        error("Memory allocation failed\n");
+    }
+    // update the next item in the list to the current head
+    new_node->next = _head;
+    // store the address to the linked datatype
+    new_node->data = data;
+    _head = new_node;
+
+    return _head;
+}
+
+//template<class retT>
+//retT *LinkedList<retT>::insert(void *data, uint32_t loc)
+//{
+//    retT *new_node = new retT [1];
+//    // make sure the new object was allocated
+//    if (0 == new_node)
+//    {
+//        error("Memory allocation failed\n");
+//    }
+//    retT *current = _head->next;
+//    retT *prev = _head;
+//    // move to the item we want to insert
+//    for (uint32_t i=1; i!=(loc-1); i++)
+//    {
+//        prev = current;
+//        current = current->next;
+//    }
+//    // store the address to the linked datatype
+//    new_node->data = data;
+//    // clear the next pointer
+//    new_node->next = 0;
+//    // update the list and store the new stuff
+//    prev->next = new_node;
+//    new_node->next = current;
+//    // store the address to the linked datatype
+//    _head->data = data;
+//
+//    return prev->next;
+//}
+
+template<class retT>
+retT *LinkedList<retT>::append(void *data)
+{
+    retT *current = _head;
+    retT *new_node = new retT [1];
+    // make sure the new object was allocated
+    if (0 == new_node)
+    {
+        error("Memory allocation failed\n");
+    }
+    // store the address to the linked datatype
+    new_node->data = data;
+    // clear the next pointer
+    new_node->next = 0;
+    // check for an empty list
+    if (0 == current)
+    {
+        _head = new_node;
+        return _head;
+    }
+    else
+    {
+        // look for the end of the list
+        while (current->next != 0)
+        {
+            current = current->next;
+        }
+        // and then add the new item to the list
+        current->next = new_node;
+    }
+
+    return current->next;
+}
+
+template<class retT>
+retT *LinkedList<retT>::remove(uint32_t loc)
+{
+    retT *current = _head;
+    retT *prev = 0;
+    // make sure we have an item to remove
+    if ((loc <= length()) && (loc > 0))
+    {
+        // move to the item we want to delete
+        if (1 == loc)
+        {
+            _head = current->next;
+            delete [] current;
+        }
+        else
+        {
+            for (uint32_t i=2; i<=loc; ++i)
+            {
+                prev = current;
+                current = current->next;
+            }
+            // store the item + 1 to replace what we are deleting
+            prev->next = current->next;
+            delete [] current;
+        }
+    }
+
+    return _head;
+}
+
+template<class retT>
+retT *LinkedList<retT>::pop(uint32_t loc)
+{
+    retT *current = _head;
+    // make sure we have something in the location
+    if ((loc > length()) || (loc == 0))
+    {
+        return 0;
+    }
+    // and if so jump down the list
+    for (uint32_t i=2; i<=loc; ++i)
+    {
+        current = current->next;
+    }
+
+    return current;
+}
+
+template<class retT>
+uint32_t LinkedList<retT>::length(void)
+{
+    int32_t count = 0;
+    retT *current = _head;
+    //loop until the end of the list is found
+    while (current != 0)
+    {
+        ++count;
+        current = current->next;
+    }
+
+    return count;
+}
+
+// pre-define the type for the linker
+template class LinkedList<node>;
+
+
+
+
+

diff -r 000000000000 -r 5530bf2d0e94 LinkedList.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LinkedList.h	Wed Jan 23 23:44:57 2019 +0000
@@ -0,0 +1,124 @@
+/**
+ * @file    LinkedList.h
+ * @brief   Core Utility - Templated Linked List class
+ * @author  sam grove
+ * @version 1.0
+ * @see     
+ *
+ * Copyright (c) 2013
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LINKEDLIST_H_
+#define LINKEDLIST_H_
+
+#include <stdint.h>
+#include "mbed.h"
+
+/**
+ *  @struct node
+ *  @brief The Linked List structure
+ */ 
+struct node
+{
+    void *data;         /*!< pointer to list member data */
+    struct node *next;  /*!< pointer to the next list member */
+};
+
+/** Example using the LinkedList Class
+ * @code
+ *  #include "mbed.h"
+ *  #include "LinkedList.h"
+ *  
+ *  LinkedList<node>list;
+ *  
+ *  int main()
+ *  {
+ *      node *tmp;
+ *      
+ *      list.push((char *)"Two\n");
+ *      list.append((char *)"Three\n");
+ *      list.append((char *)"Four\n");
+ *      list.push((char*)"One\n");
+ *      list.append((char*)"Five\n");
+ *      
+ *      for(int i=1; i<=list.length(); i++)
+ *      {
+ *          tmp = list.pop(i);
+ *          printf("%s", (char *)tmp->data);
+ *      }
+ *      
+ *      error("done\n");
+ *  }
+ * @endcode
+ */
+
+/**
+ *  @class LinkedList
+ *  @brief API abstraction for a Linked List
+ */ 
+template<class retT>
+class LinkedList
+{
+protected:
+    retT *_head;
+
+public:
+    /** Create the LinkedList object
+     */   
+    LinkedList();
+    
+    /** Deconstructor for the LinkedList object
+     *  Removes any members
+     */ 
+    ~LinkedList();
+
+    /** Add a member to the begining of the list
+     *  @param data - Some data type that is added to the list
+     *  @return The member that was just inserted (NULL if empty)
+     */
+    retT *push(void *data);
+    
+//    /** Add a member to some position in the list
+//     *  @param data - Some data type that is added to the list
+//     *  @param loc - Place in the list to put the data
+//     *  @return The member that was just inserted (NULL if empty)
+//     */
+//    retT *insert(void *data, uint32_t loc);
+    
+    /** Add a member to the end of the list
+     *  @param data - Some data type that is added to the list
+     *  @return The member that was just inserted (NULL if empty)
+     */
+    retT *append(void *data);
+    
+    /** Remove a member from the list
+     *  @param loc - The location of the member to remove
+     *  @return The head of the list
+     */
+    retT *remove(uint32_t loc);
+    
+    /** Get access to a member from the list
+     *  @param loc - The location of the member to access
+     *  @return The member that was just requested (NULL if empty or out of bounds)
+     */
+    retT *pop(uint32_t loc);
+    
+    /** Get the length of the list
+     *  @return The number of members in the list
+     */
+    uint32_t length(void);
+};
+
+#endif /* LINKEDLIST_H_ */

diff -r 000000000000 -r 5530bf2d0e94 MAX31850.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX31850.cpp	Wed Jan 23 23:44:57 2019 +0000
@@ -0,0 +1,364 @@
+#include "MAX31850.h"
+
+Serial pc(USBTX, USBRX);
+
+#define ONEWIRE_INPUT(pin)  pin->input()
+#define ONEWIRE_OUTPUT(pin) pin->output()
+#define ONEWIRE_INIT(pin)
+
+LinkedList<node> MAX31850::probes;
+ 
+ 
+MAX31850::MAX31850 (PinName data_pin, PinName power_pin, bool power_polarity) : _datapin(data_pin), _parasitepin(power_pin) {
+    int byte_counter;
+    _power_polarity = power_polarity;
+
+    _power_mosfet = power_pin != NC;
+    
+    for(byte_counter=0;byte_counter<9;byte_counter++)
+        scratchpad[byte_counter] = 0x00;
+    
+    ONEWIRE_INIT((&_datapin));
+
+    if (!unassignedProbe(&_datapin, _ROM))
+        error("No unassigned MAX31850 found!\n");
+    else {
+        _datapin.input();
+        probes.append(this);
+        _parasite_power = false; //only set up to use external power right now
+    }
+}
+
+MAX31850::~MAX31850 (void) {
+    node *tmp;
+    for(int i=1; i<=probes.length(); i++)
+    {
+        tmp = probes.pop(i);
+        if (tmp->data == this)
+            probes.remove(i);
+    }
+}
+
+ 
+bool MAX31850::onewire_reset(DigitalInOut *pin) {
+// This will return false if no devices are present on the data bus
+    bool presence=false;
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);          // bring low for 500 us
+    wait_us(500);
+    ONEWIRE_INPUT(pin);       // let the data line float high
+    wait_us(90);            // wait 90us
+    if (pin->read()==0) // see if any devices are pulling the data line low
+        presence=true;
+    wait_us(410);
+    return presence;
+}
+ 
+void MAX31850::onewire_bit_out (DigitalInOut *pin, bool bit_data) {
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);
+    wait_us(3);                 // DXP modified from 5
+    if (bit_data) {
+        pin->write(1); // bring data line high
+        wait_us(55);
+    } else {
+        wait_us(55);            // keep data line low
+        pin->write(1);
+        wait_us(10);            // DXP added to allow bus to float high before next bit_out
+    }
+}
+ 
+void MAX31850::onewire_byte_out(char data) { // output data character (least sig bit first).
+    int n;
+    for (n=0; n<8; n++) {
+        onewire_bit_out(&this->_datapin, data & 0x01);
+        data = data >> 1; // now the next bit is in the least sig bit position.
+    }
+}
+ 
+bool MAX31850::onewire_bit_in(DigitalInOut *pin) {
+    bool answer;
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);
+    wait_us(3);                 // DXP modified from 5
+    ONEWIRE_INPUT(pin);
+    wait_us(10);                // DXP modified from 5
+    answer = pin->read();
+    wait_us(45);                // DXP modified from 50
+    return answer;
+}
+ 
+char MAX31850::onewire_byte_in() { // read byte, least sig byte first
+    char answer = 0x00;
+    int i;
+    for (i=0; i<8; i++) {
+        answer = answer >> 1; // shift over to make room for the next bit
+        if (onewire_bit_in(&this->_datapin))
+            answer = answer | 0x80; // if the data port is high, make this bit a 1
+    }
+    return answer;
+}
+
+bool MAX31850::unassignedProbe(PinName pin) {
+    DigitalInOut _pin(pin);
+    ONEWIRE_INIT((&_pin));
+    char ROM_address[8];
+    return search_ROM_routine(&_pin, 0xF0, ROM_address);
+}
+ 
+bool MAX31850::unassignedProbe(DigitalInOut *pin, char *ROM_address) {
+    return search_ROM_routine(pin, 0xF0, ROM_address);
+}
+ 
+bool MAX31850::search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address) {
+    bool DS1820_done_flag = false;
+    int DS1820_last_discrepancy = 0;
+    char DS1820_search_ROM[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    
+    int discrepancy_marker, ROM_bit_index;
+    bool return_value, Bit_A, Bit_B;
+    char byte_counter, bit_mask;
+ 
+    return_value=false;
+    while (!DS1820_done_flag) {
+        if (!onewire_reset(pin)) {
+            return false;
+        } else {
+            ROM_bit_index=1;
+            discrepancy_marker=0;
+            char command_shift = command;
+            for (int n=0; n<8; n++) {           // Search ROM command
+                onewire_bit_out(pin, command_shift & 0x01);
+                command_shift = command_shift >> 1; // now the next bit is in the least sig bit position.
+            } 
+            byte_counter = 0;
+            bit_mask = 0x01;
+            while (ROM_bit_index<=64) {
+                Bit_A = onewire_bit_in(pin);
+                Bit_B = onewire_bit_in(pin);
+                if (Bit_A & Bit_B) {
+                    discrepancy_marker = 0; // data read error, this should never happen
+                    ROM_bit_index = 0xFF;
+                } else {
+                    if (Bit_A | Bit_B) {
+                        // Set ROM bit to Bit_A
+                        if (Bit_A) {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
+                        } else {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
+                        }
+                    } else {
+                        // both bits A and B are low, so there are two or more devices present
+                        if ( ROM_bit_index == DS1820_last_discrepancy ) {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
+                        } else {
+                            if ( ROM_bit_index > DS1820_last_discrepancy ) {
+                                DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
+                                discrepancy_marker = ROM_bit_index;
+                            } else {
+                                if (( DS1820_search_ROM[byte_counter] & bit_mask) == 0x00 )
+                                    discrepancy_marker = ROM_bit_index;
+                            }
+                        }
+                    }
+                    onewire_bit_out (pin, DS1820_search_ROM[byte_counter] & bit_mask);
+                    ROM_bit_index++;
+                    if (bit_mask & 0x80) {
+                        byte_counter++;
+                        bit_mask = 0x01;
+                    } else {
+                        bit_mask = bit_mask << 1;
+                    }
+                }
+            }
+            DS1820_last_discrepancy = discrepancy_marker;
+            if (ROM_bit_index != 0xFF) {
+                int i = 1;
+                node *list_container;
+                while(1) {
+                    list_container = probes.pop(i);
+                    if (list_container == NULL) {                             //End of list, or empty list
+                        if (ROM_checksum_error(DS1820_search_ROM)) {          // Check the CRC
+                            return false;
+                        }
+                        for(byte_counter=0;byte_counter<8;byte_counter++)
+                            ROM_address[byte_counter] = DS1820_search_ROM[byte_counter];
+                        return true;
+                    } else {                    //Otherwise, check if ROM is already known
+                        bool equal = true;
+                        MAX31850
+                     *pointer = (MAX31850
+                    *) list_container->data;
+                        char *ROM_compare = pointer->_ROM;
+                        
+                        for(byte_counter=0;byte_counter<8;byte_counter++) {
+                            if ( ROM_compare[byte_counter] != DS1820_search_ROM[byte_counter])
+                                equal = false;
+                        }
+                        if (equal)
+                            break;
+                        else
+                            i++;
+                    }
+                }                        
+            }
+        }
+        if (DS1820_last_discrepancy == 0)
+            DS1820_done_flag = true;
+    }
+    return return_value;
+}
+ 
+void MAX31850::match_ROM() {
+// Used to select a specific device
+    int i;
+    onewire_reset(&this->_datapin);
+    onewire_byte_out( 0x55);  //Match ROM command
+    for (i=0;i<8;i++) {
+        onewire_byte_out(_ROM[i]);
+    }
+}
+ 
+void MAX31850::skip_ROM() {
+    onewire_reset(&this->_datapin);
+    onewire_byte_out(0xCC);   // Skip ROM command
+}
+ 
+bool MAX31850::ROM_checksum_error(char *_ROM_address) {
+    char _CRC=0x00;
+    int i;
+    for(i=0;i<7;i++) // Only going to shift the lower 7 bytes
+        _CRC = CRC_byte(_CRC, _ROM_address[i]);
+    // After 7 bytes CRC should equal the 8th byte (ROM CRC)
+    return (_CRC!=_ROM_address[7]); // will return true if there is a CRC checksum mis-match         
+}
+ 
+bool MAX31850::scratchpad_checksum_error() {
+    char _CRC=0x00;
+    int i;
+    for(i=0;i<8;i++) // Only going to shift the lower 8 bytes
+        _CRC = CRC_byte(_CRC, scratchpad[i]);
+    // After 8 bytes CRC should equal the 9th byte (scratchpad CRC)
+    return (_CRC!=scratchpad[8]); // will return true if there is a CRC checksum mis-match        
+}
+ 
+char MAX31850::CRC_byte (char _CRC, char byte ) {
+    int j;
+    for(j=0;j<8;j++) {
+        if ((byte & 0x01 ) ^ (_CRC & 0x01)) {
+            // DATA ^ LSB CRC = 1
+            _CRC = _CRC>>1;
+            // Set the MSB to 1
+            _CRC = _CRC | 0x80;
+            // Check bit 3
+            if (_CRC & 0x04) {
+                _CRC = _CRC & 0xFB; // Bit 3 is set, so clear it
+            } else {
+                _CRC = _CRC | 0x04; // Bit 3 is clear, so set it
+            }
+            // Check bit 4
+            if (_CRC & 0x08) {
+                _CRC = _CRC & 0xF7; // Bit 4 is set, so clear it
+            } else {
+                _CRC = _CRC | 0x08; // Bit 4 is clear, so set it
+            }
+        } else {
+            // DATA ^ LSB CRC = 0
+            _CRC = _CRC>>1;
+            // clear MSB
+            _CRC = _CRC & 0x7F;
+            // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged
+        }
+        byte = byte>>1;
+    }
+return _CRC;
+}
+ 
+void MAX31850::readAll() {
+    // Convert temperature into scratchpad for all devices at once
+    int delay_time = 75; //default delay time
+
+    skip_ROM(); //Skip ROM command, will convert for all devices
+    
+    onewire_byte_out( 0x44);  //perform temperature conversion
+    
+    wait_ms(delay_time);
+}
+ 
+void MAX31850::read_scratchpad() {
+    // This will copy the MAX31850's 9 bytes of scratchpad data
+    // into the objects scratchpad array. Functions that use
+    // scratchpad values will automaticaly call this procedure.
+    int i;
+    match_ROM();             // Select this device
+    onewire_byte_out( 0xBE);   //Read Scratchpad command
+    for(i=0;i<9;i++) {
+        scratchpad[i] = onewire_byte_in();
+    }
+}
+
+ 
+float MAX31850::getTemp(int scale) {
+    float answer;
+    int reading;
+    read_scratchpad();
+    if (scratchpad_checksum_error()) {
+        //indicate we got a CRC error
+        answer = invalid_conversion;
+        pc.printf("CRC Error\r\n");
+    }
+    else {
+        reading = (scratchpad[1] << 8) + scratchpad[0]; //combine first two bytes of scratchpad 
+        reading  = reading >> 2; //shift right two to drop unused bits
+        if (reading & 0x2000) { //check MSB to determin sign 
+            reading = 0-((reading ^ 0x3fff) + 1); //use 2's compliment to convert back to positive number and make it a signed int
+        }
+        answer = reading +0.0; //convert to floating point
+        answer = answer / 4.0; //shift decimal place over two places
+
+        //unit convertion 
+        //checks for passed in value first and if there is none it sets the units baced on class units variable
+        switch(scale) {
+            case C:
+                break;
+            case K:
+                answer = answer + 273.15f;
+                break;
+            case F:
+                answer = answer * 1.8f + 32.0f;
+                break;
+            case R:
+                answer = answer * 1.8f + 491.67f;
+                break;
+            default:
+                switch(_units) {
+                    case C:
+                        break;
+                    case K:
+                        answer = answer + 273.15f;
+                        break;
+                    case F:
+                        answer = answer * 1.8f + 32.0f;
+                        break;
+                    case R:
+                        answer = answer * 1.8f + 491.67f;
+                        break;
+                }
+        }
+    }
+    return answer;
+}
+
+// Contributed by John M. Larkin (jlarkin@whitworth.edu)
+unsigned long long MAX31850::getId() {
+// This will return the 64 bit address of the connected MAX31850
+    unsigned long long myName = 0;
+    for (int i = 0; i<8; i++) {
+        myName = (myName<<8) | _ROM[i];
+    }
+    return myName;
+}
+
+void MAX31850::setUnits(int units) {
+    _units = units;
+}
\ No newline at end of file

diff -r 000000000000 -r 5530bf2d0e94 MAX31850.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX31850.h	Wed Jan 23 23:44:57 2019 +0000
@@ -0,0 +1,165 @@
+/* mbed MAX31850
+ Library, for the Dallas (Maxim) 1-Wire Digital Thermometer
+ * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com
+ *
+ * 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.
+ * 
+ * 
+ * This library has been adapted from the DS1820 library to work with MAX31850 thermocouple sensor
+ * Chris Roberts (croberts21@my.whitworth.edu)
+ * Craig Russell (crussell21@my.whitworth.edu)
+ * 
+ * For our application, we modified readAll() (previously convertTemperature) to force a small 
+ * wait rather than it being optional, and removed the ability to select a single sensor.
+ * 
+ * getTemp() (previously temperature) has been updated to deal with the correct number of bits that 
+ * the temperature is stored in as well as updated convertions to all four units
+ * 
+ *  as well as adding a setUnits() function to set the 
+ * units that the sensor will return.
+ * 
+ * We removed some functionality that dealt with parasite power. 
+ * 
+ *
+ */
+
+#ifndef MBED_MAX31850_H
+#define MBED_MAX31850_H
+
+#include "mbed.h"
+#include "LinkedList.h"
+
+#define C 0 //celsius 
+#define K 1 //Kelvin
+#define F 2 //fahrenheit
+#define R 3 //Rankin
+
+extern Serial pc;
+
+/** MAX31850
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "MAX31850.h"
+ *
+ * MAX31850 probe(DATA_PIN);
+ *  
+ * int main() {
+ *     while(true) {
+ *         probe.convertTemperature(true, MAX31850::all_devices); //Start temperature conversion, wait until ready
+ *         printf("It is %3.1foC\r\n", probe.temperature());
+ *         wait(1);
+ *     }
+ * }
+ * @endcode
+ */
+class MAX31850
+ {
+public:
+    enum devices{
+        this_device,     // command applies to only this device
+        all_devices };   // command applies to all devices
+    
+    enum {
+        invalid_conversion = -1000
+    };
+
+    /** Create a probe object connected to the specified pins
+    * 
+    * The probe might either by regular powered or parasite powered. If it is parasite
+    * powered and power_pin is set, that pin will be used to switch an external mosfet connecting
+    * data to Vdd. If it is parasite powered and the pin is not set, the regular data pin
+    * is used to supply extra power when required. This will be sufficient as long as the 
+    * number of probes is limitted.
+    * 
+    * For our application, we have the functions set up to only use external power. The constructor still supports
+    * parasite power but the functions to not support it.
+    */
+    MAX31850 (PinName data_pin, PinName power_pin = NC, bool power_polarity = 0); // Constructor with parasite power pin
+  
+    ~MAX31850();
+
+    /** Function to see if there are MAX31850
+     *  devices left on a pin which do not have a corresponding MAX31850
+     *  object
+    *
+    * @return - true if there are one or more unassigned devices, otherwise false
+      */
+    static bool unassignedProbe(PinName pin);
+
+    /** This routine will initiate the temperature conversion within
+      *  all MAX31850
+      *  probes. 
+      */
+    void readAll();
+
+    /** This function will return the probe temperature. Approximately 10ms per
+      * probe to read its scratchpad, do CRC check and convert temperature on the LPC1768.
+      *
+      * @scratchpad scale, may be either 'c', 'f', 'k', and 'r'
+      * @returns temperature for that scale, or MAX31850::invalid_conversion (-1000) if CRC error detected.
+      */
+    float getTemp(int scale = 4);     
+
+    /** This function returns the 64 bit address associated with a
+      * particular DS18B20.
+      *
+      * Contributed by John M. Larkin (jlarkin@whitworth.edu)
+      *
+      * @returns unsigned long long
+      */
+    unsigned long long getId();
+
+
+    /** This function sets the _units variable to the 
+     * users desired temperature units
+     */
+    void setUnits(int);
+    
+
+private:
+    bool _parasite_power;
+    bool _power_mosfet;
+    bool _power_polarity;
+    
+    static char CRC_byte(char _CRC, char byte );
+    static bool onewire_reset(DigitalInOut *pin);
+    void match_ROM();
+    void skip_ROM();
+    static bool search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address);
+    static void onewire_bit_out (DigitalInOut *pin, bool bit_data);
+    void onewire_byte_out(char data);
+    static bool onewire_bit_in(DigitalInOut *pin);
+    char onewire_byte_in();
+    static bool ROM_checksum_error(char *_ROM_address);
+    bool scratchpad_checksum_error();
+    void read_scratchpad();
+    static bool unassignedProbe(DigitalInOut *pin, char *ROM_address);
+
+    DigitalInOut _datapin;
+    DigitalOut _parasitepin;
+    
+    char _ROM[8];
+    char scratchpad[9];
+    int _units;
+    
+    static LinkedList<node> probes;
+};
+#endif
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