UART Class Reference

#include <UART.hpp>

Inheritance diagram for UART:

Collaboration diagram for UART:

Public Member Functions
	UART ()=default
	~UART () override
void	VConnect () override
void	VDisconnect () override
size_t	VSendData (void *, const size_t) override
size_t	VReceiveData (void *, const size_t) override
Public Member Functions inherited from ICommunication
virtual	~ICommunication ()
virtual void	VInitialize ()
bool	IsConnected () const

Protected Attributes
int	tty_fd
Protected Attributes inherited from ICommunication
bool	m_connected

Detailed Description

Definition at line 6 of file UART.hpp.

Constructor & Destructor Documentation

UART()

UART::UART ( )

default

~UART()

UART::~UART ( )

override

Definition at line 19 of file UART.cpp.

            {
}

Member Function Documentation

VConnect()

void UART::VConnect ( )

overridevirtual

Implements ICommunication.

Definition at line 22 of file UART.cpp.

                    {
  /* TODO: how do we know, that we have to listen on THS1 instead of THS0 e.g.
   * we need a reference here and also a description of how or where to find
   * that information
   * https://stackoverflow.com/questions/2530096/how-to-find-all-serial-devices-ttys-ttyusb-on-linux-without-opening-them
   * Description: pinmux is needed by the kernel to know the HW setup
   *
   * THS = Tegra High Speed
   * ls /dev/ttyS* and
   * ls /dev/ttyTHS* are the same UART HW but different driver
   *
   * on agx:
   * "The initial pinmux should set all of the these pins, except for the power,
   * UART RX TX and two I2C busses, to GPIO at boot. The UART and I2C busses
   * should not be used for GPIO."
   * 
   * pinmux manually on agx:
   * https://www.elinux.org/Jetson/AGX_Xavier_Update_Pinmux_Manually
   *
   * for all uart pinmuxs:
   * sudo cat /sys/kernel/debug/tegra_pinctrl_reg
   *
   * Linux setserial tool:
   * https://www.cyberciti.biz/faq/find-out-linux-serial-ports-with-setserial/
   *
   * Jetson AGX Header Pinout:
   * https://www.jetsonhacks.com/nvidia-jetson-agx-xavier-gpio-header-pinout/
   * taken from:
   * http://developer.nvidia.com/embedded/dlc/jetson-xavier-developer-kit-carrier-board-spec
   *
   * Xavier Forum Links:
   * https://devtalk.nvidia.com/default/topic/1058946/
   *
   * from
   * https://devtalk.nvidia.com/default/topic/1062552/jetson-agx-xavier/accesseing-uart2-in-tegra/post/5380741/#5380741
   * device tree determines routing of serial devices or what function a GPIO
   * will take
   * DT is included in BSP -> HW changes, but drivers stay the same
   *
   * ls -l /dev/ttyS* /dev/ttyTHS*
   * if group name is dialout -> it is connected to some serial HW
   *
   * Additional Information:
   * reverse DTB
   * https://forum.digilentinc.com/topic/2427-how-to-decompile-dtb-file/
   *
   * DT reference: https://elinux.org/Device_Tree_Reference
   *
   * devicetree.org
   * 
   */
#ifndef JETSON_DEVICE
#error "Please define JETSON_DEVICE variable"
#endif
#if JETSON_DEVICE == 0
  const char* ttyPath = "/dev/ttyTHS0";
#else
  const char* ttyPath = "/dev/ttyTHS1";
#endif
  speed_t speed = B1000000; /* 1MBps Baudrate */
  tty_fd        = open(ttyPath, O_RDWR | O_NOCTTY | O_SYNC);
 
  if(tty_fd < 0) {
    std::cout << "ERROR: Could not open tty " << *ttyPath;
    return;
  }
 
  struct termios tty;
  memset(&tty, 0, sizeof tty);
 
  tty.c_iflag     = 0;
  tty.c_oflag     = 0;
  tty.c_cflag     = (CS8 | CLOCAL | CREAD);
  tty.c_lflag     = 0;
  tty.c_cc[VMIN]  = 1;
  tty.c_cc[VTIME] = 5;
 
  cfsetospeed(&tty, speed);
  cfsetispeed(&tty, speed);
 
  tcsetattr(tty_fd, TCSANOW, &tty);
 
  tcflush(tty_fd, TCIOFLUSH);
 
  m_connected = true;
}

References ICommunication::m_connected, and tty_fd.

VDisconnect()

void UART::VDisconnect ( )

overridevirtual

Implements ICommunication.

Definition at line 109 of file UART.cpp.

                       {
  if(tty_fd < 0) {
    return;
  }
  close(tty_fd);
 
  m_connected = false;
}

References ICommunication::m_connected, and tty_fd.

VReceiveData()

size_t UART::VReceiveData ( void *  pData, const size_t  len  )

overridevirtual

Implements ICommunication.

Definition at line 123 of file UART.cpp.

                                                       {
  size_t bytesread = read(tty_fd, pData, len);
  return bytesread;
}

References tty_fd.

VSendData()

size_t UART::VSendData ( void *  pData, const size_t  len  )

overridevirtual

Implements ICommunication.

Definition at line 118 of file UART.cpp.

                                                    {
  size_t written = write(tty_fd, pData, len);
  return written;
}

References tty_fd.

Member Data Documentation

tty_fd

int UART::tty_fd

protected

Definition at line 43 of file UART.hpp.

Referenced by VConnect(), VDisconnect(), VReceiveData(), and VSendData().

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The documentation for this class was generated from the following files:

• nodes/ECUNode/com/UART.hpp
• nodes/ECUNode/com/UART.cpp