sibo-playground/code/inventory/scan.c

/*
 * scan.c - Phase 1 barcode diagnostic: software-triggered scan over TTY:D.
 *
 * TTY:D is the top-slot bar code interface. It did not auto-transmit on a scan,
 * so this build uses the documented escape-sequence trigger (I/O Devices
 * Reference, HC Intelligent Bar Code Reader chapter):
 *   <Esc>-y1J  enable single-read mode
 *   <Esc>-y1K  "read next scan" - arms the reader for one label
 * After each decoded label (terminated by CR) it re-arms with another K.
 * Every received byte is streamed as a decimal value.
 *
 * <Esc>=0x1b, '-'=0x2d, 'y'=0x79. Escape sequences carry no embedded spaces.
 */
#include <plib.h>

GLDEF_C INT main(VOID)
{
    VOID *chan;
    UBYTE b;
    INT   err, n, c;

    static TEXT cmdJ[5] = { 0x1b, '-', 'y', '1', 'J' };  /* single-read mode on */
    static TEXT cmdK[5] = { 0x1b, '-', 'y', '1', 'K' };  /* trigger one scan    */

    err = p_open(&chan, "TTY:D", (UINT)-1);
    p_printf("open TTY:D: %d\n", err);
    if (err < 0) {
        p_printf("Press a key to exit.\n");
        p_getch();
        return 1;
    }

    err = p_write(chan, cmdJ, 5);
    p_printf("single-read mode (Esc-y1J): %d\n", err);
    err = p_write(chan, cmdK, 5);
    p_printf("trigger (Esc-y1K): %d\n", err);

    p_printf("\nPoint at a barcode. Streaming bytes:\n\n");

    for (;;) {
        n = p_read(chan, &b, 1);
        if (n < 0) {
            p_printf("<e%d>", n);
            continue;
        }
        if (n == 0)
            continue;
        c = b;
        p_printf(" %d", c);
        if (c == 13 || c == 10) {
            p_printf(" <EOL>\n");
            p_write(chan, cmdK, 5);   /* re-arm for the next scan */
        }
    }
}