mirror of
https://github.com/RobTillaart/Arduino.git
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123 lines
2.6 KiB
C++
123 lines
2.6 KiB
C++
#pragma once
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//
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// FILE: DHT20.h
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// AUTHOR: Rob Tillaart
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// PURPOSE: Arduino library for DHT20 I2C temperature and humidity sensor.
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// VERSION: 0.2.1
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// HISTORY: See DHT20.cpp
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// URL: https://github.com/RobTillaart/DHT20
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//
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// Always check datasheet - front view
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//
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// +--------------+
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// VDD ----| 1 |
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// SDA ----| 2 DHT20 |
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// GND ----| 3 |
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// SCL ----| 4 |
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// +--------------+
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#include "Arduino.h"
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#include "Wire.h"
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#define DHT20_LIB_VERSION (F("0.2.1"))
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#define DHT20_OK 0
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#define DHT20_ERROR_CHECKSUM -10
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#define DHT20_ERROR_CONNECT -11
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#define DHT20_MISSING_BYTES -12
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#define DHT20_ERROR_BYTES_ALL_ZERO -13
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#define DHT20_ERROR_READ_TIMEOUT -14
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#define DHT20_ERROR_LASTREAD -15
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class DHT20
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{
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public:
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// CONSTRUCTOR
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// fixed address 0x38
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DHT20(TwoWire *wire = &Wire);
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// start the I2C
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#if defined(ESP8266) || defined(ESP32)
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bool begin(const uint8_t dataPin, const uint8_t clockPin);
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#endif
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bool begin();
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bool isConnected();
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uint8_t getAddress();
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// ASYNCHRONUOUS CALL
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// trigger acquisition.
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int requestData();
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// read the raw data.
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int readData();
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// converts raw databits to temperature and humidity.
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int convert();
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// SYNCHRONUOUS CALL
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// blocking read call to read + convert data
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int read();
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// access the converted temperature & humidity
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float getHumidity();
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float getTemperature();
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// OFFSET 1st order adjustments
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void setHumOffset(float offset);
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void setTempOffset(float offset);
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float getHumOffset();
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float getTempOffset();
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// READ STATUS
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uint8_t readStatus();
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// 3 wrapper functions around readStatus()
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bool isCalibrated();
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bool isMeasuring();
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bool isIdle();
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// status from last read()
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int internalStatus();
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// TIMING
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uint32_t lastRead();
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uint32_t lastRequest();
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// RESET (new since 0.1.4)
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// use with care
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// returns number of registers reset => must be 3
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// 3 = OK
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// 0,1,2 = error.
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// 255 = no reset needed.
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// See datasheet 7.4 Sensor Reading Process, point 1
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// use with care
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uint8_t resetSensor();
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private:
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float _humidity;
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float _temperature;
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float _humOffset;
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float _tempOffset;
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uint8_t _status;
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uint32_t _lastRequest;
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uint32_t _lastRead;
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uint8_t _bits[7];
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uint8_t _crc8(uint8_t *ptr, uint8_t len);
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// use with care
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bool _resetRegister(uint8_t reg);
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TwoWire* _wire;
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};
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// -- END OF FILE --
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