cbus_led_blink.c

// Author Toshifumi NISHINAGA < tnishinaga.dev AT gmail DOT com >
// License: GPLv2

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <ftdi.h>

static inline void ftdi_bitmode_fail(struct ftdi_context *ftdi, int f)
{
    fprintf(stderr, "ftdi_set_bitmode failed, error %d (%s)\n", f, ftdi_get_error_string(ftdi));
    ftdi_usb_close(ftdi);
    ftdi_free(ftdi);
    exit(-1);
}

int main(void)
{
    struct ftdi_context *ftdi;
    int f;

    ftdi = ftdi_new();
    if (ftdi == 0) {
        fprintf(stderr, "ftdi new failed\n");
        return EXIT_FAILURE;
    }

    // open ft230x
    f = ftdi_usb_open(ftdi, 0x0403, 0x6015);
    if (f < 0 && f != -5) {
        fprintf(stderr, "unable to open ftdi device: %d (%s)\n", f, ftdi_get_error_string(ftdi));
        ftdi_free(ftdi);
        exit(-1);
    }

    printf("ftdi open succeeded: %d\n",f);

    for(int i = 0; i < 10; i++) {
        // set bitmask
        // all output, all high
        printf("Set high\n");
        f = ftdi_set_bitmode(ftdi, 0xff, BITMODE_CBUS);
        if (f < 0){
            ftdi_bitmode_fail(ftdi, f);
        }
        sleep(1);
        // all output, all low
        printf("Set low\n");
        f = ftdi_set_bitmode(ftdi, 0xf0, BITMODE_CBUS);
        if (f < 0){
            ftdi_bitmode_fail(ftdi, f);
        }
        sleep(1);
    }

    printf("finish\n");

    ftdi_disable_bitbang(ftdi);
    ftdi_usb_close(ftdi);
    ftdi_free(ftdi);

    return 0;
}

run.sh

#!/bin/sh

gcc -o cbus_led_blink cbus_led_blink.c -std=c11
./cbus_led_blink