sibo-playground/code/inventory/scan.c

/*
 * scan.c - Phase 1 barcode diagnostic: minimal TTY:D barcode-driver read.
 *
 * TTY:D is the top-slot bar code interface (I/O Devices Reference, HC
 * Intelligent Bar Code Reader chapter). Opening it powers the interface and
 * the scanner; by default the scanner is enabled and in auto-read mode, and it
 * transmits each decoded label as ASCII text terminated by a carriage return.
 *
 * Earlier attempts failed for self-inflicted reasons: a P_FSET forced 9600/8/1
 * (wrong if the scanner uses another rate, which garbles the data) and a
 * 64-byte read blocked forever with no terminator set. This build does NEITHER:
 * it opens TTY:D, changes nothing, and reads ONE byte at a time, streaming each
 * value. Scan during the brief active window after launch (re-trigger with the
 * scan key if needed).
 */
#include <plib.h>

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

    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;
    }

    p_printf("Scan now. Streaming bytes:\n\n");

    for (;;) {
        n = p_read(chan, &b, 1);   /* one byte; no reconfiguration at all */
        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");
    }
}