Send data to a barcode scanner over RS232 serial port - c++

Question

I have a bar-code scanner which is connecting through RS232 serial port. I need to write a program to connect this device with the PC and transmit data. I already wrote some basic methods to initialize a communication link and tried to test by sending a BEEP command to the device but it is not beeping as expected. So I think there is something wrong with my source code. Please somebody help me complete the source code. Below is the written source code
01)DeviceRS232.h
#ifndef DEVICERS232_H
#define DEVICERS232_H
extern "C"
{
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
}
#include <string>
#define MAX_SERIAL_PORT_NO 30
class DeviceRS232
{
public:
DeviceRS232();
virtual ~DeviceRS232();
int fdRS232; // file descriptor for the serial port
void setSerialPort(std::string sp);
void setBaudRate(long baud);
void setDataBits(int dataBit);
void setStopBits(int stopBit);
void setNumberOfParityBits(int nparityBits);
void setDefaultAttributes();
long getBaudRate();
std::string getSerialPort();
int openSerialPort();
int readUserConfiguration();
int sendDataBuffer(const unsigned char *dataBuffer, size_t bufferSize);
void closeSerialPort();
protected:
std::string serialPort; // Serial port like /dev/ttyS0
long baudRate; // Scanner baud rate
int dataBits; // data bits
int stopBits; // stop bits
int numberOfParityBits; // number of parity bits
termios oldSerialPortSetting; // Current values of termios structure for /dev/ttyS0
termios newSerialPortSetting; // new termios attributes for /dev/ttyS0
private:
};
#endif // DEVICERS232_H
2) DeviceRS232.cpp
#include "DeviceRS232.h"
DeviceRS232::DeviceRS232()
{
//ctor
}
DeviceRS232::~DeviceRS232()
{
//dtor
}
void DeviceRS232::setSerialPort(std::string sp)
{
serialPort = sp;
}
void DeviceRS232::setBaudRate(long baud)
{
baudRate = baud;
}
void DeviceRS232::setDataBits(int dataBit)
{
dataBits = dataBit;
}
void DeviceRS232::setStopBits(int stopBit)
{
stopBits = stopBit;
}
void DeviceRS232::setNumberOfParityBits(int nparityBits)
{
numberOfParityBits = nparityBits;
}
void DeviceRS232::setDefaultAttributes()
{
std::string sp = "/dev/ttyS0";
long baud = 9600;
int dataBit = 1;
int stopBit = 1;
int nparityBits = 0;
setSerialPort(sp);
setBaudRate(baud);
setDataBits(dataBit);
setStopBits(stopBit);
setNumberOfParityBits(nparityBits);
}
long DeviceRS232::getBaudRate()
{
return baudRate;
}
std::string DeviceRS232::getSerialPort()
{
return serialPort;
}
int DeviceRS232::openSerialPort()
{
int fd, baudr, status, portStatus;
setDefaultAttributes();
switch(getBaudRate())
{
case 50 : baudr = B50;
break;
case 75 : baudr = B75;
break;
case 110 : baudr = B110;
break;
case 134 : baudr = B134;
break;
case 150 : baudr = B150;
break;
case 200 : baudr = B200;
break;
case 300 : baudr = B300;
break;
case 600 : baudr = B600;
break;
case 1200 : baudr = B1200;
break;
case 1800 : baudr = B1800;
break;
case 2400 : baudr = B2400;
break;
case 4800 : baudr = B4800;
break;
case 9600 : baudr = B9600;
break;
case 19200 : baudr = B19200;
break;
case 38400 : baudr = B38400;
break;
case 57600 : baudr = B57600;
break;
case 115200 : baudr = B115200;
break;
case 230400 : baudr = B230400;
break;
case 460800 : baudr = B460800;
break;
case 500000 : baudr = B500000;
break;
case 576000 : baudr = B576000;
break;
case 921600 : baudr = B921600;
break;
case 1000000 : baudr = B1000000;
break;
default : printf("invalid baudrate\n");
return(1);
break;
}
// Open serial port
fd = open(getSerialPort().c_str(), O_RDWR | O_NOCTTY | O_NDELAY);
if(fd == -1)
{
printf("Unable to open serial port...\n");
return 1;
}
fdRS232 = fd;
status = tcgetattr(fdRS232, &oldSerialPortSetting);
if(status == -1)
{
close(fdRS232);
printf("Unable to get serial port attributes...\n");
return 1;
}
memset(&newSerialPortSetting, 0, sizeof(newSerialPortSetting));
newSerialPortSetting.c_cflag = baudr | CS8 | CLOCAL | CREAD; //
newSerialPortSetting.c_iflag = IGNPAR;
newSerialPortSetting.c_oflag = 0;
newSerialPortSetting.c_lflag = 0;
newSerialPortSetting.c_cc[VMIN] = 0;
newSerialPortSetting.c_cc[VTIME] = 0;
status = tcsetattr(fdRS232, TCSANOW, &newSerialPortSetting);
if(status==-1)
{
close(fdRS232);
perror("unable to adjust portsettings ");
return 1;
}
// Get the status of opened serial port
if(ioctl(fdRS232, TIOCMGET, &portStatus) == -1)
{
perror("Unable to get port status");
return 1;
}
// Tern on DTR and RTS
portStatus |= TIOCM_DTR;
portStatus |= TIOCM_RTS;
// Set the status of the port with new DTR, RTS values
if(ioctl(fdRS232, TIOCMSET, &portStatus) == -1)
{
perror("Unable to set port status...");
return 1;
}
return 0;
}
int DeviceRS232::sendDataBuffer(const unsigned char *dataBuffer, size_t bufferSize)
{
return write(fdRS232, dataBuffer, bufferSize);
}
void DeviceRS232::closeSerialPort()
{
int portStatus;
if(ioctl(fdRS232, TIOCMGET, &portStatus) == -1)
{
perror("Unable to get the port status");
}
// Tern off DTR and RTS
portStatus &= ~TIOCM_DTR;
portStatus &= ~TIOCM_RTS;
// Set the status of the port with new DTR, RTS values
if(ioctl(fdRS232, TIOCMSET, &portStatus) == -1)
{
perror("Unable to set port status...");
}
close(fdRS232);
}
3) main.cpp
#include <iostream>
extern "C"
{
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
}
#include "DeviceRS232.h"
using namespace std;
int main()
{
//char sendBuffer[4096] = " ";
unsigned char sendBeep[] = {0x05, 0xE6, 0x04, 0x00, 0x0D, 0x00, 0x00};
unsigned char ledOn[] = {0x05, 0xE7, 0x04, 0x00, 0x0D, 0x00};
unsigned char val[7];
cout << "********************** RS232 - SSI **********************" << endl << endl;
DeviceRS232 dev_rs232;
dev_rs232.setDefaultAttributes();
dev_rs232.openSerialPort();
//----------------------------------------------------
//for(int x=0; x<10; x++)
//{
// dev_rs232.sendDataBuffer(sendBeep, sizeof(sendBeep));
//}
//----------------------------------------------------
int sizeSent = dev_rs232.sendDataBuffer(sendBeep, sizeof(sendBeep));
if( sizeSent > 0)
{
printf("Data sent: %d...\n", sizeSent);
}
sleep(10);
dev_rs232.closeSerialPort();
cout << "*********************************************************" << endl;
return 0;
}
unsigned char sendBeep[] = {0x05, 0xE6, 0x04, 0x00, 0x0D, 0x00, 0x00}; is written considering the bar-device's serial port communication protocol specification.
(Edited to add the output)
Out put:
********************** RS232 - SSI **********************
Data sent: 7...
*********************************************************
Process returned 0 (0x0) execution time : 10.006 s
Press ENTER to continue.
All helps and suggestions are welcome. Thanks.

Answer 1

#include <iostream>
extern "C"
{
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
}
#include "DeviceRS232.h"
using namespace std;
int main()
{
unsigned char sendBuffer[4096] = "Test test test...";
unsigned char sendBeep[] = {0x05, 0xE6, 0x04, 0x00, 0x11, 0x46, 0x00};
unsigned char ledOn[] = {0x05, 0xE7, 0x04, 0x00, 0x0D, 0x00};
unsigned char val[7];
//-------------------------------------------------------------------------
unsigned char commonBuffer[257];
int iChecksum;
int i;
commonBuffer[ 1 ] = (unsigned char)0xC6;
commonBuffer[ 2 ] = (unsigned char)0x04;
commonBuffer[ 3 ] = (unsigned char)0x08; // Permanant Chnage
commonBuffer[ 4 ] = (unsigned char)0x11; // Beep after setting. FF for No Beep
commonBuffer[ 5 ] = (unsigned char)0xEE; // Decorder parameter to set (238)
commonBuffer[ 6 ] = (unsigned char)0x01; // Value to set
commonBuffer[ 0 ] = (unsigned char)0x07; // Length
iChecksum = 0;
for (i = 0; i < 7; i++)
{
iChecksum += commonBuffer[i];
}
commonBuffer[i++] = (char)(((-iChecksum) >> 8) & 0xFF); // Add Checksum into the command
commonBuffer[i++] = (char)((-iChecksum) & 0xFF);
//-------------------------------------------------------------------------
cout << "********************** RS232 - SSI **********************" << endl << endl;
DeviceRS232 dev_rs232;
dev_rs232.setDefaultAttributes();
dev_rs232.openSerialPort();
//----------------------------------------------------
//for(int x=0; x<10; x++)
//{
// dev_rs232.sendDataBuffer(sendBeep, sizeof(sendBeep));
//}
//----------------------------------------------------
int sizeSent = dev_rs232.sendDataBuffer(commonBuffer, sizeof(commonBuffer));
if( sizeSent > 0)
{
printf("Data sent: %d...\n", sizeSent);
}
sleep(1);
dev_rs232.closeSerialPort();
cout << "*********************************************************" << endl;
return 0;
}