Impressão QR CODE / PDF147 utilizando C nas impressoras ESC POS

raduanmendes
(usa Outra)

Enviado em 23/11/2017 - 16:07h

Depois de muito procurar uma solução de como imprimir QrCode nas impressoras do padrão ESC/POS utilizando C no linux, não encontrei nada em C, então resolvir criar uma função e disponibiliza-la para a comunidade.

Espero auxiliar os desenvolvedores que estão na parte do QrCode para sistemas SAT e NFCe.

Segue código abaixo:

int Print_qrcode_EscPos (char* szText)

{

  int iRet =0;

  char szLine[2046];

  char szBuffer[]= "\x1D\x28\x6B\x03\x00\x31\x43?"

                   "\x1D\x28\x6B\x03\x00\x31\x45\x33"

                   "\x1D\x28\x6B??\x31\x50\x30";



  int iSize = strlen(szText) + 3;

  int lsb, msb;

  memset(szLine, 0, sizeof(szLine));

  

  FILE *f = fopen("qr_print.prt", "w");

  if (f == NULL) f = stderr;



  lsb = (iSize % 256);

  msb = (iSize / 256);

 

  szBuffer[7]  = (char) 3; //Tamanho do QrCode  -> 2 ao 12.

  szBuffer[19] = (char) lsb;

  szBuffer[20] = (char) msb;



  fwrite (szBuffer, sizeof(char), sizeof(szBuffer)-1, f);

  fwrite (szText , sizeof(char), strlen(szText), f);

  fwrite ("\x1D\x28\x6B\x03\x00\x31\x51\x30", sizeof(char), 8, f);

  fclose(f);

  

  f = fopen("qr_print.prt", "r");

  {

    fgets(szLine, sizeof(szLine), f);

    fclose(f)

  }



   iRet = dwrite (glPrinterHandle, (unsigned char *) szLine, (sizeof(szBuffer)-1) + (strlen(szText)) + 8);

   //glPrinterHandle   -> Porta de impressão.



  return iRet;

}

 

no meu código a variavel glPrinterHandle é o meu device, a impressora EPSON.

O código cria o arquivo qr_print.prt com os comandos, a maneira mais facil de validar é danod em echo na porta:

echo qr_print.prt > /dev/ttyS1

Onde ttyS1 deve ser substituido pela sua porta.

Espero ter ajudado, abraço!

Raduan Mendes

denio
(usa Slackware)

Enviado em 28/02/2018 - 16:47h

gcc qr.c

qr.c: In function ‘Print_qrcode_EscPos’:
qr.c:12:15: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
int iSize = strlen(szText) + 3;
^
qr.c:12:15: warning: incompatible implicit declaration of built-in function ‘strlen’
qr.c:12:15: note: include ‘<string.h>’ or provide a declaration of ‘strlen’
qr.c:14:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration]
memset(szLine, 0, sizeof(szLine));
^
qr.c:14:3: warning: incompatible implicit declaration of built-in function ‘memset’
qr.c:14:3: note: include ‘<string.h>’ or provide a declaration of ‘memset’
qr.c:35:3: error: expected ‘;’ before ‘}’ token
}
^
qr.c:37:11: warning: implicit declaration of function ‘dwrite’ [-Wimplicit-function-declaration]
iRet = dwrite (glPrinterHandle, (unsigned char *) szLine, (sizeof(szBuffer)-1) + (strlen(szText)) + 8);
^
qr.c:37:19: error: ‘glPrinterHandle’ undeclared (first use in this function)
iRet = dwrite (glPrinterHandle, (unsigned char *) szLine, (sizeof(szBuffer)-1) + (strlen(szText)) + 8);
^
qr.c:37:19: note: each undeclared identifier is reported only once for each function it appears in

denio
(usa Slackware)

Enviado em 28/02/2018 - 16:52h

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

denio
(usa Slackware)

Enviado em 28/02/2018 - 16:52h

gcc qr.c
qr.c: In function ‘Print_qrcode_EscPos’:
qr.c:36:3: error: expected ‘;’ before ‘}’ token
}
^
qr.c:38:11: warning: implicit declaration of function ‘dwrite’ [-Wimplicit-function-declaration]
iRet = dwrite (glPrinterHandle, (unsigned char *) szLine, (sizeof(szBuffer)-1) + (strlen(szText)) + 8);
^
qr.c:38:19: error: ‘glPrinterHandle’ undeclared (first use in this function)
iRet = dwrite (glPrinterHandle, (unsigned char *) szLine, (sizeof(szBuffer)-1) + (strlen(szText)) + 8);
^
qr.c:38:19: note: each undeclared identifier is reported only once for each function it appears in