SerialPort.hpp
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///
/// \file SerialPort.hpp
/// \author Geoffrey Hunter <gbmhunter@gmail.com> (www.mbedded.ninja)
/// \created 2014-01-07
/// \last-modified 2019-05-30
/// \brief The main serial port class.
/// \details
/// See README.rst in repo root dir for more info.
// Header guard
#ifndef SERIAL_PORT_SERIAL_PORT_H
#define SERIAL_PORT_SERIAL_PORT_H
// System headers
#include <string>
#include <fstream> // For file I/O (reading/writing to COM port)
#include <sstream>
// #include <termios.h> // POSIX terminal control definitions (struct termios)
// #include <asm/termios.h> // Terminal control definitions (struct termios)
#include <vector>
#include <asm/ioctls.h>
#include <asm/termbits.h>
// User headers
#include "Exception.hpp"
namespace mn {
namespace CppLinuxSerial {
/// \brief Represents the baud rate "types" that can be used with the serial port. STANDARD represents all
/// the standard baud rates as provided by UNIX, CUSTOM represents a baud rate defined by an arbitray integer.
enum class BaudRateType {
STANDARD,
CUSTOM,
};
/// \brief Strongly-typed enumeration of baud rates for use with the SerialPort class
/// \details Specifies all the same baud rates as UNIX, as well as B_CUSTOM to specify your
/// own. See https://linux.die.net/man/3/cfsetispeed for list of supported UNIX baud rates.
enum class BaudRate {
B_0,
B_50,
B_75,
B_110,
B_134,
B_150,
B_200,
B_300,
B_600,
B_1200,
B_1800,
B_2400,
B_4800,
B_9600,
B_19200,
B_38400,
B_57600,
B_115200,
B_230400,
B_460800,
B_CUSTOM, // Placeholder
};
/// \brief Enumeration of all the valid num. of data bits. Must align with the options
/// provided in termbits.h, i.e. CS5, CS6, CS7 and CS8.
enum class NumDataBits {
FIVE,
SIX,
SEVEN,
EIGHT,
};
enum class Parity {
NONE,
EVEN,
ODD,
};
enum class NumStopBits {
ONE,
TWO,
};
/// \brief Represents the state of the serial port.
enum class State {
CLOSED,
OPEN,
};
/// \brief SerialPort object is used to perform rx/tx serial communication.
class SerialPort {
public:
/// \brief Default constructor. You must specify at least the device before calling Open().
SerialPort();
/// \brief Constructor that sets up serial port with the basic (required) parameters.
SerialPort(const std::string &device, BaudRate baudRate);
/// \brief Constructor that sets up serial port and allows the user to specify all the common parameters.
SerialPort(const std::string &device, BaudRate baudRate, NumDataBits numDataBits, Parity parity, NumStopBits numStopBits);
/// \brief Constructor that sets up serial port with the basic parameters, and a custom baud rate.
SerialPort(const std::string &device, speed_t baudRate);
/// \brief Destructor. Closes serial port if still open.
virtual ~SerialPort();
/// \brief Sets the device to use for serial port communications.
/// \details Method can be called when serial port is in any state.
void SetDevice(const std::string &device);
/// \brief Call this to set a standard baud rate.
void SetBaudRate(BaudRate baudRate);
/// \brief Call this to set a custom baud rate.
void SetBaudRate(speed_t baudRate);
/// \brief Call this to set the num. of data bits.
void SetNumDataBits(NumDataBits numDataBits);
/// \brief Call this to set the parity.
void SetParity(Parity parity);
void SetNumStopBits(NumStopBits numStopBits);
/// \brief Sets the read timeout (in milliseconds)/blocking mode.
/// \details Only call when state != OPEN. This method manupulates VMIN and VTIME.
/// \param timeout_ms Set to -1 to infinite timeout, 0 to return immediately with any data (non
/// blocking, or >0 to wait for data for a specified number of milliseconds). Timeout will
/// be rounded to the nearest 100ms (a Linux API restriction). Maximum value limited to
/// 25500ms (another Linux API restriction).
void SetTimeout(int32_t timeout_ms);
/// \brief Enables/disables echo.
/// \param value Pass in true to enable echo, false to disable echo.
void SetEcho(bool value);
/// \brief Opens the COM port for use.
/// \throws CppLinuxSerial::Exception if device cannot be opened.
/// \note Must call this before you can configure the COM port.
void Open();
/// \brief Closes the COM port.
void Close();
/// \brief Sends a text message over the com port.
/// \param data The data that will be written to the COM port.
/// \throws CppLinuxSerial::Exception if state != OPEN.
void Write(const std::string& data);
/// \brief Sends a binary message over the com port.
/// \param data The data that will be written to the COM port.
/// \throws CppLinuxSerial::Exception if state != OPEN.
void WriteBinary(const std::vector<uint8_t>& data);
/// \brief Use to read text from the COM port.
/// \param data The object the read characters from the COM port will be saved to.
/// \param wait_ms The amount of time to wait for data. Set to 0 for non-blocking mode. Set to -1
/// to wait indefinitely for new data.
/// \throws CppLinuxSerial::Exception if state != OPEN.
void Read(std::string& data);
/// \brief Use to read binary data from the COM port.
/// \param data The object the read uint8_t bytes from the COM port will be saved to.
/// \param wait_ms The amount of time to wait for data. Set to 0 for non-blocking mode. Set to -1
/// to wait indefinitely for new data.
/// \throws CppLinuxSerial::Exception if state != OPEN.
void ReadBinary(std::vector<uint8_t>& data);
/// \brief Use to get number of bytes available in receive buffer.
/// \returns The number of bytes available in the receive buffer (ready to be read).
/// \throws CppLinuxSerial::Exception if state != OPEN.
int32_t Available();
private:
/// \brief Configures the tty device as a serial port.
/// \warning Device must be open (valid file descriptor) when this is called.
void ConfigureTermios();
// void SetTermios(termios myTermios);
/// \brief Returns a populated termios2 structure for the serial port pointed to by the file descriptor.
termios2 GetTermios2();
/// \brief Assigns the provided tty settings to the serial port pointed to by the file descriptor.
void SetTermios2(termios2 tty);
/// \brief Keeps track of the serial port's state.
State state_;
/// \brief The file path to the serial port device (e.g. "/dev/ttyUSB0").
std::string device_;
/// \brief The type of baud rate that the user has specified.
BaudRateType baudRateType_;
/// \brief The current baud rate if baudRateType_ == STANDARD.
BaudRate baudRateStandard_;
/// \brief The current baud rate if baudRateType_ == CUSTOM.
speed_t baudRateCustom_;
/// \brief The num. of data bits. Defaults to 8 (most common).
NumDataBits numDataBits_ = NumDataBits::EIGHT;
/// \brief The parity. Defaults to none (most common).
Parity parity_ = Parity::NONE;
/// \brief The num. of stop bits. Defaults to 1 (most common).
NumStopBits numStopBits_ = NumStopBits::ONE;
/// \brief The file descriptor for the open file. This gets written to when Open() is called.
int fileDesc_;
bool echo_;
int32_t timeout_ms_;
std::vector<char> readBuffer_;
unsigned char readBufferSize_B_;
static constexpr BaudRate defaultBaudRate_ = BaudRate::B_57600;
static constexpr int32_t defaultTimeout_ms_ = -1;
static constexpr unsigned char defaultReadBufferSize_B_ = 255;
};
} // namespace CppLinuxSerial
} // namespace mn
#endif // #ifndef SERIAL_PORT_SERIAL_PORT_H