Rostislav Krylov / Thermistor

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Dependents:   condato_Coldchainlogger condato_Coldchainlogger

Thermistor.h@0:000a8be2414d, 2016-03-09 (annotated)

Committer:
unix_guru
Date:
Wed Mar 09 13:52:45 2016 +0000
Revision:
0:000a8be2414d
Child:
1:601e1435dfb8
Created Thermistor Library for re-use

Who changed what in which revision?

UserRevisionLine numberNew contents of line
unix_guru 0:000a8be2414d 1 #ifndef THERMISTOR_H
unix_guru 0:000a8be2414d 2 #define THERMISTOR_H
unix_guru 0:000a8be2414d 3 ///
unix_guru 0:000a8be2414d 4 /// @mainpage Thermistor Temperature library
unix_guru 0:000a8be2414d 5 ///
unix_guru 0:000a8be2414d 6 /// This is a Thermistor to Temerature conversion library
unix_guru 0:000a8be2414d 7 ///
unix_guru 0:000a8be2414d 8 /// Much thanks to @Adafruit for this tutorial:
unix_guru 0:000a8be2414d 9 /// https://learn.adafruit.com/thermistor/using-a-thermistor
unix_guru 0:000a8be2414d 10 ///
unix_guru 0:000a8be2414d 11 /// The 100K Thermistor is configured with a 4.7k series resistor
unix_guru 0:000a8be2414d 12 /// tied to vcc (3.3v) like this:
unix_guru 0:000a8be2414d 13 ///
unix_guru 0:000a8be2414d 14 /// +3.3v
unix_guru 0:000a8be2414d 15 /// |
unix_guru 0:000a8be2414d 16 /// \
unix_guru 0:000a8be2414d 17 /// / 4.7k series resistor
unix_guru 0:000a8be2414d 18 /// \
unix_guru 0:000a8be2414d 19 /// /
unix_guru 0:000a8be2414d 20 /// |
unix_guru 0:000a8be2414d 21 /// .-----------O To Anlog pin on FRDM board
unix_guru 0:000a8be2414d 22 /// |
unix_guru 0:000a8be2414d 23 /// \
unix_guru 0:000a8be2414d 24 /// /
unix_guru 0:000a8be2414d 25 /// Thermistor 100k Nominal
unix_guru 0:000a8be2414d 26 /// \
unix_guru 0:000a8be2414d 27 /// /
unix_guru 0:000a8be2414d 28 /// |
unix_guru 0:000a8be2414d 29 /// ---
unix_guru 0:000a8be2414d 30 /// GND
unix_guru 0:000a8be2414d 31 ///
unix_guru 0:000a8be2414d 32 ///
unix_guru 0:000a8be2414d 33 /// @author Michael J. Ball
unix_guru 0:000a8be2414d 34 /// unix_guru at hotmail.com
unix_guru 0:000a8be2414d 35 /// @unix_guru on Twitter
unix_guru 0:000a8be2414d 36 /// March 2016
unix_guru 0:000a8be2414d 37 ///
unix_guru 0:000a8be2414d 38 /// @code
unix_guru 0:000a8be2414d 39 /// Thermistor bed(PTB10);
unix_guru 0:000a8be2414d 40 /// printf("Temperature is %f Celcius", bed.get_temperature());
unix_guru 0:000a8be2414d 41 ///
unix_guru 0:000a8be2414d 42 /// ...
unix_guru 0:000a8be2414d 43 /// @endcode
unix_guru 0:000a8be2414d 44 ///
unix_guru 0:000a8be2414d 45 /// @license
unix_guru 0:000a8be2414d 46 /// Licensed under the Apache License, Version 2.0 (the "License");
unix_guru 0:000a8be2414d 47 /// you may not use this file except in compliance with the License.
unix_guru 0:000a8be2414d 48 /// You may obtain a copy of the License at
unix_guru 0:000a8be2414d 49 ///
unix_guru 0:000a8be2414d 50 /// http://www.apache.org/licenses/LICENSE-2.0
unix_guru 0:000a8be2414d 51 ///
unix_guru 0:000a8be2414d 52 /// Unless required by applicable law or agreed to in writing, software
unix_guru 0:000a8be2414d 53 /// distributed under the License is distributed on an "AS IS" BASIS,
unix_guru 0:000a8be2414d 54 /// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
unix_guru 0:000a8be2414d 55 /// See the License for the specific language governing permissions and
unix_guru 0:000a8be2414d 56 /// limitations under the License.
unix_guru 0:000a8be2414d 57 ///
unix_guru 0:000a8be2414d 58
unix_guru 0:000a8be2414d 59
unix_guru 0:000a8be2414d 60 #include "mbed.h"
unix_guru 0:000a8be2414d 61
unix_guru 0:000a8be2414d 62
unix_guru 0:000a8be2414d 63 #define THERMISTORNOMINAL 100000 // 100k default
unix_guru 0:000a8be2414d 64 // temp. for nominal resistance (almost always 25 C)
unix_guru 0:000a8be2414d 65 #define TEMPERATURENOMINAL 25
unix_guru 0:000a8be2414d 66 // The beta coefficient of the thermistor (usually 3000-4000)
unix_guru 0:000a8be2414d 67 #define BCOEFFICIENT 3950
unix_guru 0:000a8be2414d 68 // the value of the 'other' resistor
unix_guru 0:000a8be2414d 69 #define SERIESRESISTOR 4700
unix_guru 0:000a8be2414d 70
unix_guru 0:000a8be2414d 71
unix_guru 0:000a8be2414d 72 class Thermistor {
unix_guru 0:000a8be2414d 73 public:
unix_guru 0:000a8be2414d 74 Thermistor(PinName pin);
unix_guru 0:000a8be2414d 75 /** Receives a PinName variable.
unix_guru 0:000a8be2414d 76 * @param pin mbed pin to which the thermistor is connected
unix_guru 0:000a8be2414d 77 */
unix_guru 0:000a8be2414d 78
unix_guru 0:000a8be2414d 79
unix_guru 0:000a8be2414d 80 float get_temperature();
unix_guru 0:000a8be2414d 81 /** This is the workhorse routine that calculates the temperature
unix_guru 0:000a8be2414d 82 * using the Steinhart-Hart equation for thermistors
unix_guru 0:000a8be2414d 83 * https://en.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation
unix_guru 0:000a8be2414d 84 */
unix_guru 0:000a8be2414d 85 void init(); // Set default Steinhart-Hart values
unix_guru 0:000a8be2414d 86 void set_ThermistorNominal(float thermnom); // Change the thermistors nominal resistance
unix_guru 0:000a8be2414d 87 void set_TemperatureNominal(float tempnom); // Change the thermistors nominal temperature
unix_guru 0:000a8be2414d 88 void set_BCoefficient(float bcoefficient); // Change the thermistors BCoefficient
unix_guru 0:000a8be2414d 89 void set_SeriesResistor(float resistor); // Change the value of the series resistor
unix_guru 0:000a8be2414d 90
unix_guru 0:000a8be2414d 91 private:
unix_guru 0:000a8be2414d 92 AnalogIn _pin;
unix_guru 0:000a8be2414d 93 float ThermistorNominal;
unix_guru 0:000a8be2414d 94 float TemperatureNominal;
unix_guru 0:000a8be2414d 95 float BCoefficient;
unix_guru 0:000a8be2414d 96 float SeriesResistor;
unix_guru 0:000a8be2414d 97 };
unix_guru 0:000a8be2414d 98
unix_guru 0:000a8be2414d 99 #endif