SDI12.h

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/*** ==================== Code Organization ======================
 * - Includes, Defines, & Variable Declarations
 * - Buffer Setup
 * - Reading from the SDI-12 Buffer
 * - Constructor, Destructor, Begins, and Setters
 * - Using more than one SDI-12 object, isActive() and setActive()
 * - Setting Proper Data Line States
 * - Waking up and Talking to the Sensors
 * - Interrupt Service Routine (getting the data into the buffer)
 */
 
 
#ifndef SRC_SDI12_H_
#define SRC_SDI12_H_
 
//  Import Required Libraries
#include <inttypes.h>      // integer types library
#include <Arduino.h>       // Arduino core library
#include <Stream.h>        // Arduino Stream library
#include "SDI12_boards.h"  //  Include timer information
 
typedef const __FlashStringHelper* FlashString;
 
#define NO_IGNORE_CHAR '\x01'
 
#ifndef SDI12_BUFFER_SIZE
#define SDI12_BUFFER_SIZE 81
#endif
 
#if defined(ESP32) || defined(ESP8266)
enum LookaheadMode {
  SKIP_ALL,
  SKIP_NONE,
  SKIP_WHITESPACE
};
#define READTIME sdi12timer.SDI12TimerRead()
#else
#define READTIME TCNTX
#endif  // defined(ESP32) || defined(ESP8266)
 
class SDI12 : public Stream {
 private:
  static SDI12* _activeObject;
  static SDI12Timer sdi12timer;
  static const uint16_t bitWidth_micros;
  static const uint16_t lineBreak_micros;
  static const uint16_t marking_micros;
 
  static const uint8_t txBitWidth;
  static const uint8_t rxWindowWidth;
  static const uint8_t bitsPerTick_Q10;
  static const uint8_t WAITING_FOR_START_BIT;
 
  static uint16_t prevBitTCNT;
  static uint8_t rxState;
  static uint8_t rxMask;
  static uint8_t rxValue;
 
  static uint16_t mul8x8to16(uint8_t x, uint8_t y);
 
  static uint16_t bitTimes(uint8_t dt);
 private:
  static uint8_t _rxBuffer[SDI12_BUFFER_SIZE];
  static volatile uint8_t _rxBufferTail;
  static volatile uint8_t _rxBufferHead;
  bool _bufferOverflow;
 public:
  int available() override;
  int peek() override;
  void clearBuffer();
  int read() override;
  void flush() override {}
 
  long parseInt(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
 
  float parseFloat(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
 
 protected:
  int peekNextDigit(LookaheadMode lookahead, bool detectDecimal);
 private:
  uint8_t _dataPin;
 
 public:
  SDI12();
  explicit SDI12(int8_t dataPin);
  ~SDI12();
  void begin();
  void begin(int8_t dataPin);
  void end();
  int16_t TIMEOUT;
  void setTimeoutValue(int16_t value);
  int8_t getDataPin();
  void setDataPin(int8_t dataPin);
 public:
  bool setActive();
 
  bool isActive();
 private:
  typedef enum SDI12_STATES {
    SDI12_DISABLED,
    SDI12_ENABLED,
    SDI12_HOLDING,
    SDI12_TRANSMITTING,
    SDI12_LISTENING
  } SDI12_STATES;
 
#ifndef __AVR__
  static uint8_t parity_even_bit(uint8_t v);
#endif
 
  void setPinInterrupts(bool enable);
  void setState(SDI12_STATES state);
 
 public:
  void forceHold();
  void forceListen();
 private:
  void wakeSensors(int8_t extraWakeTime = 0);
  void writeChar(uint8_t out);
 
 public:
  virtual size_t write(uint8_t byte);
 
  void sendCommand(String& cmd, int8_t extraWakeTime = 0);
  void sendCommand(const char* cmd, int8_t extraWakeTime = 0);
  void sendCommand(FlashString cmd, int8_t extraWakeTime = 0);
 
  void sendResponse(String& resp);
  void sendResponse(const char* resp);
  void sendResponse(FlashString resp);
 
 
 private:
  void startChar();
  void receiveISR();
  void charToBuffer(uint8_t c);
 
 public:
  static void handleInterrupt();
 
  // #define SDI12_EXTERNAL_PCINT
};
 
#endif  // SRC_SDI12_H_