RS485.h

#pragma once
//
//    FILE: RS485.h
//  AUTHOR: Rob Tillaart
//    DATE: 30-okt-2017
// VERSION: 0.5.1
// PURPOSE: Arduino library for RS485 modules
//     URL: https://github.com/RobTillaart/RS485


#include "Arduino.h"
#include "ASCII_CONTROL.h"

#define RS485_LIB_VERSION        (F("0.5.1"))


class RS485 : public Stream
{
public:
  RS485(Stream * stream, uint8_t sendPin, uint8_t deviceID = 0);

  uint8_t  getDeviceID();


  //      Stream interface
  int     available();
  int     read();
  int     peek();
  void    flush();


  //      Write
  size_t  write(uint8_t c);
  size_t  write(char * array, uint8_t length);  //  wrapper
  size_t  write(uint8_t * array, uint8_t length);


  //      Mode functions
  inline void setTXmode() { digitalWrite(_sendPin, HIGH); };
  inline void setRXmode() { digitalWrite(_sendPin, LOW); };
  uint8_t     getMode()   { return digitalRead(_sendPin) == HIGH; };


  //  EXPERIMENTAL
  //  - in a derived class?
  //  - use at own risk
  //  send ASCII encoded messages from one master to multiple clients.
  //       msg[] = 32..127
  //       len   =  1.. 48 (internal receive buffer is 50)
  size_t   send(uint8_t receiverID, uint8_t msg[], uint8_t len);
  bool     receive(uint8_t &senderID, uint8_t msg[], uint8_t &len);

  //  EXPERIMENTAL
  size_t   send(uint8_t receiverID, char msg[], uint8_t len);
  bool     receive(uint8_t &senderID, char msg[], uint8_t &len);

  //  EXPERIMENTAL
  void     setMicrosPerByte(uint16_t mpb) { _microsPerByte = mpb; };
  uint16_t getMicrosPerByte() { return _microsPerByte; };


private:
  Stream   * _stream;
  uint8_t  _sendPin       = 0;
  uint8_t  _deviceID      = 0;
  uint16_t _microsPerByte = 1100;

  //       EXPERIMENTAL
  uint8_t _bidx = 0;
  uint8_t _buffer[50];  //  internal receive buffer
};


//  -- END OF FILE --