GY-63_MS5611/libraries/MAX6675/MAX6675.h
2023-11-12 10:18:34 +01:00

114 lines
2.7 KiB
C++

#pragma once
//
// FILE: MAX6675.h
// AUTHOR: Rob Tillaart
// VERSION: 0.1.3
// PURPOSE: Arduino library for MAX6675 chip for K type thermocouple
// DATE: 2022-01-12
// URL: https://github.com/RobTillaart/MAX6675
// TODO Breakout board
//
// +---------+
// Vin | o |
// 3V3 | o |
// GND | o O | Thermocouple
// D0 | o O | Thermocouple
// CS | o |
// CLK | o |
// +---------+
#include "Arduino.h"
#include "SPI.h"
#define MAX6675_LIB_VERSION (F("0.1.3"))
#define MAX6675_NO_TEMPERATURE -999
// STATE constants returned by read()
// TODO check
#define STATUS_OK 0x00
#define STATUS_ERROR 0x04
#define STATUS_NOREAD 0x80
#define STATUS_NO_COMMUNICATION 0x81
// Thermocouples working is based upon Seebeck effect.
// Different TC have a different Seebeck Coefficient (µV/°C)
// See http://www.analog.com/library/analogDialogue/archives/44-10/thermocouple.html
//
// K_TC == 41.276 µV/°C
class MAX6675
{
public:
MAX6675();
// HW SPI
void begin(uint8_t select);
// SW SPI
void begin(uint8_t clock, uint8_t select, uint8_t miso);
// returns state - bit field: 0 = STATUS_OK
uint8_t read();
float getTemperature(void) { return _temperature + _offset; };
uint8_t getStatus(void) const { return _status; };
// use offset to calibrate the TC.
void setOffset(const float t) { _offset = t; };
float getOffset() const { return _offset; };
uint32_t lastRead() { return _lastTimeRead; };
uint16_t getRawData() { return _rawData;};
// speed in Hz
void setSPIspeed(uint32_t speed);
uint32_t getSPIspeed() { return _SPIspeed; };
void setSWSPIdelay(uint16_t del = 0) { _swSPIdelay = del; };
uint16_t getSWSPIdelay() { return _swSPIdelay; };
// ESP32 specific
#if defined(ESP32)
void selectHSPI() { _useHSPI = true; };
void selectVSPI() { _useHSPI = false; };
bool usesHSPI() { return _useHSPI; };
bool usesVSPI() { return !_useHSPI; };
// to overrule ESP32 default hardware pins
void setGPIOpins(uint8_t clock, uint8_t miso, uint8_t mosi, uint8_t select);
#endif
private:
uint32_t _read();
uint8_t _status;
float _temperature;
float _offset;
uint32_t _lastTimeRead;
uint16_t _rawData;
bool _hwSPI;
uint8_t _clock;
uint8_t _miso;
uint8_t _select;
uint16_t _swSPIdelay = 0;
uint32_t _SPIspeed;
SPIClass * mySPI;
SPISettings _spi_settings;
#if defined(ESP32)
bool _useHSPI = true;
#endif
};
// -- END OF FILE --