Chris Roberts / MAX31850

Library for MAX31850 thermocouple temperature sensor

MAX31850.h@0:5530bf2d0e94, 2019-01-23 (annotated)

Committer:
croberts21
Date:
Wed Jan 23 23:44:57 2019 +0000
Revision:
0:5530bf2d0e94
All files added

Who changed what in which revision?

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croberts21 0:5530bf2d0e94 1 /* mbed MAX31850
croberts21 0:5530bf2d0e94 2 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer
croberts21 0:5530bf2d0e94 3 * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com
croberts21 0:5530bf2d0e94 4 *
croberts21 0:5530bf2d0e94 5 * Permission is hereby granted, free of charge, to any person obtaining a copy
croberts21 0:5530bf2d0e94 6 * of this software and associated documentation files (the "Software"), to deal
croberts21 0:5530bf2d0e94 7 * in the Software without restriction, including without limitation the rights
croberts21 0:5530bf2d0e94 8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
croberts21 0:5530bf2d0e94 9 * copies of the Software, and to permit persons to whom the Software is
croberts21 0:5530bf2d0e94 10 * furnished to do so, subject to the following conditions:
croberts21 0:5530bf2d0e94 11 *
croberts21 0:5530bf2d0e94 12 * The above copyright notice and this permission notice shall be included in
croberts21 0:5530bf2d0e94 13 * all copies or substantial portions of the Software.
croberts21 0:5530bf2d0e94 14 *
croberts21 0:5530bf2d0e94 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
croberts21 0:5530bf2d0e94 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
croberts21 0:5530bf2d0e94 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
croberts21 0:5530bf2d0e94 18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
croberts21 0:5530bf2d0e94 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
croberts21 0:5530bf2d0e94 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
croberts21 0:5530bf2d0e94 21 * THE SOFTWARE.
croberts21 0:5530bf2d0e94 22 *
croberts21 0:5530bf2d0e94 23 *
croberts21 0:5530bf2d0e94 24 * This library has been adapted from the DS1820 library to work with MAX31850 thermocouple sensor
croberts21 0:5530bf2d0e94 25 * Chris Roberts (croberts21@my.whitworth.edu)
croberts21 0:5530bf2d0e94 26 * Craig Russell (crussell21@my.whitworth.edu)
croberts21 0:5530bf2d0e94 27 *
croberts21 0:5530bf2d0e94 28 * For our application, we modified readAll() (previously convertTemperature) to force a small
croberts21 0:5530bf2d0e94 29 * wait rather than it being optional, and removed the ability to select a single sensor.
croberts21 0:5530bf2d0e94 30 *
croberts21 0:5530bf2d0e94 31 * getTemp() (previously temperature) has been updated to deal with the correct number of bits that
croberts21 0:5530bf2d0e94 32 * the temperature is stored in as well as updated convertions to all four units
croberts21 0:5530bf2d0e94 33 *
croberts21 0:5530bf2d0e94 34 * as well as adding a setUnits() function to set the
croberts21 0:5530bf2d0e94 35 * units that the sensor will return.
croberts21 0:5530bf2d0e94 36 *
croberts21 0:5530bf2d0e94 37 * We removed some functionality that dealt with parasite power.
croberts21 0:5530bf2d0e94 38 *
croberts21 0:5530bf2d0e94 39 *
croberts21 0:5530bf2d0e94 40 */
croberts21 0:5530bf2d0e94 41
croberts21 0:5530bf2d0e94 42 #ifndef MBED_MAX31850_H
croberts21 0:5530bf2d0e94 43 #define MBED_MAX31850_H
croberts21 0:5530bf2d0e94 44
croberts21 0:5530bf2d0e94 45 #include "mbed.h"
croberts21 0:5530bf2d0e94 46 #include "LinkedList.h"
croberts21 0:5530bf2d0e94 47
croberts21 0:5530bf2d0e94 48 #define C 0 //celsius
croberts21 0:5530bf2d0e94 49 #define K 1 //Kelvin
croberts21 0:5530bf2d0e94 50 #define F 2 //fahrenheit
croberts21 0:5530bf2d0e94 51 #define R 3 //Rankin
croberts21 0:5530bf2d0e94 52
croberts21 0:5530bf2d0e94 53 extern Serial pc;
croberts21 0:5530bf2d0e94 54
croberts21 0:5530bf2d0e94 55 /** MAX31850
croberts21 0:5530bf2d0e94 56 *
croberts21 0:5530bf2d0e94 57 * Example:
croberts21 0:5530bf2d0e94 58 * @code
croberts21 0:5530bf2d0e94 59 * #include "mbed.h"
croberts21 0:5530bf2d0e94 60 * #include "MAX31850.h"
croberts21 0:5530bf2d0e94 61 *
croberts21 0:5530bf2d0e94 62 * MAX31850 probe(DATA_PIN);
croberts21 0:5530bf2d0e94 63 *
croberts21 0:5530bf2d0e94 64 * int main() {
croberts21 0:5530bf2d0e94 65 * while(true) {
croberts21 0:5530bf2d0e94 66 * probe.convertTemperature(true, MAX31850::all_devices); //Start temperature conversion, wait until ready
croberts21 0:5530bf2d0e94 67 * printf("It is %3.1foC\r\n", probe.temperature());
croberts21 0:5530bf2d0e94 68 * wait(1);
croberts21 0:5530bf2d0e94 69 * }
croberts21 0:5530bf2d0e94 70 * }
croberts21 0:5530bf2d0e94 71 * @endcode
croberts21 0:5530bf2d0e94 72 */
croberts21 0:5530bf2d0e94 73 class MAX31850
croberts21 0:5530bf2d0e94 74 {
croberts21 0:5530bf2d0e94 75 public:
croberts21 0:5530bf2d0e94 76 enum devices{
croberts21 0:5530bf2d0e94 77 this_device, // command applies to only this device
croberts21 0:5530bf2d0e94 78 all_devices }; // command applies to all devices
croberts21 0:5530bf2d0e94 79
croberts21 0:5530bf2d0e94 80 enum {
croberts21 0:5530bf2d0e94 81 invalid_conversion = -1000
croberts21 0:5530bf2d0e94 82 };
croberts21 0:5530bf2d0e94 83
croberts21 0:5530bf2d0e94 84 /** Create a probe object connected to the specified pins
croberts21 0:5530bf2d0e94 85 *
croberts21 0:5530bf2d0e94 86 * The probe might either by regular powered or parasite powered. If it is parasite
croberts21 0:5530bf2d0e94 87 * powered and power_pin is set, that pin will be used to switch an external mosfet connecting
croberts21 0:5530bf2d0e94 88 * data to Vdd. If it is parasite powered and the pin is not set, the regular data pin
croberts21 0:5530bf2d0e94 89 * is used to supply extra power when required. This will be sufficient as long as the
croberts21 0:5530bf2d0e94 90 * number of probes is limitted.
croberts21 0:5530bf2d0e94 91 *
croberts21 0:5530bf2d0e94 92 * For our application, we have the functions set up to only use external power. The constructor still supports
croberts21 0:5530bf2d0e94 93 * parasite power but the functions to not support it.
croberts21 0:5530bf2d0e94 94 */
croberts21 0:5530bf2d0e94 95 MAX31850 (PinName data_pin, PinName power_pin = NC, bool power_polarity = 0); // Constructor with parasite power pin
croberts21 0:5530bf2d0e94 96
croberts21 0:5530bf2d0e94 97 ~MAX31850();
croberts21 0:5530bf2d0e94 98
croberts21 0:5530bf2d0e94 99 /** Function to see if there are MAX31850
croberts21 0:5530bf2d0e94 100 * devices left on a pin which do not have a corresponding MAX31850
croberts21 0:5530bf2d0e94 101 * object
croberts21 0:5530bf2d0e94 102 *
croberts21 0:5530bf2d0e94 103 * @return - true if there are one or more unassigned devices, otherwise false
croberts21 0:5530bf2d0e94 104 */
croberts21 0:5530bf2d0e94 105 static bool unassignedProbe(PinName pin);
croberts21 0:5530bf2d0e94 106
croberts21 0:5530bf2d0e94 107 /** This routine will initiate the temperature conversion within
croberts21 0:5530bf2d0e94 108 * all MAX31850
croberts21 0:5530bf2d0e94 109 * probes.
croberts21 0:5530bf2d0e94 110 */
croberts21 0:5530bf2d0e94 111 void readAll();
croberts21 0:5530bf2d0e94 112
croberts21 0:5530bf2d0e94 113 /** This function will return the probe temperature. Approximately 10ms per
croberts21 0:5530bf2d0e94 114 * probe to read its scratchpad, do CRC check and convert temperature on the LPC1768.
croberts21 0:5530bf2d0e94 115 *
croberts21 0:5530bf2d0e94 116 * @scratchpad scale, may be either 'c', 'f', 'k', and 'r'
croberts21 0:5530bf2d0e94 117 * @returns temperature for that scale, or MAX31850::invalid_conversion (-1000) if CRC error detected.
croberts21 0:5530bf2d0e94 118 */
croberts21 0:5530bf2d0e94 119 float getTemp(int scale = 4);
croberts21 0:5530bf2d0e94 120
croberts21 0:5530bf2d0e94 121 /** This function returns the 64 bit address associated with a
croberts21 0:5530bf2d0e94 122 * particular DS18B20.
croberts21 0:5530bf2d0e94 123 *
croberts21 0:5530bf2d0e94 124 * Contributed by John M. Larkin (jlarkin@whitworth.edu)
croberts21 0:5530bf2d0e94 125 *
croberts21 0:5530bf2d0e94 126 * @returns unsigned long long
croberts21 0:5530bf2d0e94 127 */
croberts21 0:5530bf2d0e94 128 unsigned long long getId();
croberts21 0:5530bf2d0e94 129
croberts21 0:5530bf2d0e94 130
croberts21 0:5530bf2d0e94 131 /** This function sets the _units variable to the
croberts21 0:5530bf2d0e94 132 * users desired temperature units
croberts21 0:5530bf2d0e94 133 */
croberts21 0:5530bf2d0e94 134 void setUnits(int);
croberts21 0:5530bf2d0e94 135
croberts21 0:5530bf2d0e94 136
croberts21 0:5530bf2d0e94 137 private:
croberts21 0:5530bf2d0e94 138 bool _parasite_power;
croberts21 0:5530bf2d0e94 139 bool _power_mosfet;
croberts21 0:5530bf2d0e94 140 bool _power_polarity;
croberts21 0:5530bf2d0e94 141
croberts21 0:5530bf2d0e94 142 static char CRC_byte(char _CRC, char byte );
croberts21 0:5530bf2d0e94 143 static bool onewire_reset(DigitalInOut *pin);
croberts21 0:5530bf2d0e94 144 void match_ROM();
croberts21 0:5530bf2d0e94 145 void skip_ROM();
croberts21 0:5530bf2d0e94 146 static bool search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address);
croberts21 0:5530bf2d0e94 147 static void onewire_bit_out (DigitalInOut *pin, bool bit_data);
croberts21 0:5530bf2d0e94 148 void onewire_byte_out(char data);
croberts21 0:5530bf2d0e94 149 static bool onewire_bit_in(DigitalInOut *pin);
croberts21 0:5530bf2d0e94 150 char onewire_byte_in();
croberts21 0:5530bf2d0e94 151 static bool ROM_checksum_error(char *_ROM_address);
croberts21 0:5530bf2d0e94 152 bool scratchpad_checksum_error();
croberts21 0:5530bf2d0e94 153 void read_scratchpad();
croberts21 0:5530bf2d0e94 154 static bool unassignedProbe(DigitalInOut *pin, char *ROM_address);
croberts21 0:5530bf2d0e94 155
croberts21 0:5530bf2d0e94 156 DigitalInOut _datapin;
croberts21 0:5530bf2d0e94 157 DigitalOut _parasitepin;
croberts21 0:5530bf2d0e94 158
croberts21 0:5530bf2d0e94 159 char _ROM[8];
croberts21 0:5530bf2d0e94 160 char scratchpad[9];
croberts21 0:5530bf2d0e94 161 int _units;
croberts21 0:5530bf2d0e94 162
croberts21 0:5530bf2d0e94 163 static LinkedList<node> probes;
croberts21 0:5530bf2d0e94 164 };
croberts21 0:5530bf2d0e94 165 #endif