mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
114 lines
2.6 KiB
C++
114 lines
2.6 KiB
C++
#pragma once
|
|
//
|
|
// FILE: MAX6675.h
|
|
// AUTHOR: Rob Tillaart
|
|
// VERSION: 0.1.1
|
|
// 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("0.1.1"))
|
|
|
|
#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 --
|
|
|