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https://github.com/RobTillaart/Arduino.git
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107 lines
2.4 KiB
C++
107 lines
2.4 KiB
C++
#pragma once
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//
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// FILE: MAX6675.h
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// AUTHOR: Rob Tillaart
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// VERSION: 0.2.0
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// PURPOSE: Arduino library for MAX6675 chip for K type thermocouple
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// DATE: 2022-01-12
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// URL: https://github.com/RobTillaart/MAX6675
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// TODO Breakout board
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//
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// +---------+
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// Vin | o |
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// 3V3 | o |
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// GND | o O | Thermocouple
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// D0 | o O | Thermocouple
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// CS | o |
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// CLK | o |
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// +---------+
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#include "Arduino.h"
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#include "SPI.h"
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#define MAX6675_LIB_VERSION (F("0.2.0"))
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#ifndef __SPI_CLASS__
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#if defined(ARDUINO_ARCH_RP2040)
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#define __SPI_CLASS__ SPIClassRP2040
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#else
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#define __SPI_CLASS__ SPIClass
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#endif
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#endif
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#define MAX6675_NO_TEMPERATURE -999
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// STATE constants returned by read()
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// TODO check
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#define STATUS_OK 0x00
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#define STATUS_ERROR 0x04
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#define STATUS_NOREAD 0x80
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#define STATUS_NO_COMMUNICATION 0x81
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// Thermocouples working is based upon Seebeck effect.
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// Different TC have a different Seebeck Coefficient (µV/°C)
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// See http://www.analog.com/library/analogDialogue/archives/44-10/thermocouple.html
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//
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// K_TC == 41.276 µV/°C
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class MAX6675
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{
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public:
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// HW SPI
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MAX6675(uint8_t select, __SPI_CLASS__ * mySPI);
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// SW SPI
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MAX6675(uint8_t select, uint8_t miso, uint8_t clock);
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void begin();
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// returns state - bit field: 0 = STATUS_OK
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uint8_t read();
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float getTemperature(void) { return _temperature + _offset; };
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uint8_t getStatus(void) const { return _status; };
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// use offset to calibrate the TC.
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void setOffset(const float t) { _offset = t; };
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float getOffset() const { return _offset; };
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uint32_t lastRead() { return _lastTimeRead; };
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uint16_t getRawData() { return _rawData;};
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// speed in Hz
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void setSPIspeed(uint32_t speed);
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uint32_t getSPIspeed() { return _SPIspeed; };
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void setSWSPIdelay(uint16_t del = 0) { _swSPIdelay = del; };
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uint16_t getSWSPIdelay() { return _swSPIdelay; };
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private:
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uint32_t _read();
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uint8_t _status;
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float _temperature;
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float _offset;
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uint32_t _lastTimeRead;
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uint16_t _rawData;
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bool _hwSPI;
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uint8_t _clock;
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uint8_t _miso;
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uint8_t _select;
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uint16_t _swSPIdelay = 0;
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uint32_t _SPIspeed;
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__SPI_CLASS__ * _mySPI;
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SPISettings _spi_settings;
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};
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// -- END OF FILE --
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