2 * collectd - src/multimeter.c
3 * Copyright (C) 2005,2006 Peter Holik
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Peter Holik <peter at holik.at>
22 * Used multimeter: Metex M-4650CR
29 #if HAVE_TERMIOS_H && HAVE_SYS_IOCTL_H && HAVE_MATH_H
31 # include <sys/ioctl.h>
33 # define MULTIMETER_HAVE_READ 1
35 # define MULTIMETER_HAVE_READ 0
36 # error "multimeter cannot read!"
39 #if MULTIMETER_HAVE_READ
42 static int multimeter_timeval_sub (struct timeval *tv1, struct timeval *tv2,
45 if ((tv1->tv_sec < tv2->tv_sec) ||
46 ((tv1->tv_sec == tv2->tv_sec) && (tv1->tv_usec < tv2->tv_usec)))
49 res->tv_sec = tv1->tv_sec - tv2->tv_sec;
50 res->tv_usec = tv1->tv_usec - tv2->tv_usec;
52 assert ((res->tv_sec > 0) || ((res->tv_sec == 0) && (res->tv_usec > 0)));
54 while (res->tv_usec < 0)
56 res->tv_usec += 1000000;
61 #define LINE_LENGTH 14
62 static int multimeter_read_value(double *value)
64 int retry = 3; /* sometimes we receive garbadge */
68 struct timeval time_end;
70 tcflush(fd, TCIFLUSH);
72 if (gettimeofday (&time_end, NULL) < 0)
75 ERROR ("multimeter plugin: gettimeofday failed: %s",
76 sstrerror (errno, errbuf,
84 char buf[LINE_LENGTH];
88 struct timeval timeout;
89 struct timeval time_now;
96 if (gettimeofday (&time_now, NULL) < 0)
99 ERROR ("multimeter plugin: "
100 "gettimeofday failed: %s",
101 sstrerror (errno, errbuf,
105 if (multimeter_timeval_sub (&time_end, &time_now, &timeout) == -1)
108 status = select(fd+1, &rfds, NULL, NULL, &timeout);
110 if (status > 0) /* usually we succeed */
112 status = read(fd, buf, LINE_LENGTH);
114 if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
117 /* Format: "DC 00.000mV \r" */
118 if (status > 0 && status == LINE_LENGTH)
120 *value = strtod(buf + 2, &range);
122 if ( range > (buf + 6) )
128 case 'p': *value *= 1.0E-12; break;
129 case 'n': *value *= 1.0E-9; break;
130 case 'u': *value *= 1.0E-6; break;
131 case 'm': *value *= 1.0E-3; break;
132 case 'k': *value *= 1.0E3; break;
133 case 'M': *value *= 1.0E6; break;
134 case 'G': *value *= 1.0E9; break;
138 return (-1); /* Overflow */
140 return (0); /* value received */
144 else if (!status) /* Timeout */
148 else if ((status == -1) && ((errno == EAGAIN) || (errno == EINTR)))
152 else /* status == -1 */
155 ERROR ("multimeter plugin: "
157 sstrerror (errno, errbuf, sizeof (errbuf)));
163 return (-2); /* no value received */
164 } /* int multimeter_read_value */
166 static int multimeter_init (void)
169 char device[] = "/dev/ttyS ";
171 for (i = 0; i < 10; i++)
173 device[strlen(device)-1] = i + '0';
175 if ((fd = open(device, O_RDWR | O_NOCTTY)) > 0)
181 tios.c_cflag = B1200 | CS7 | CSTOPB | CREAD | CLOCAL;
182 tios.c_iflag = IGNBRK | IGNPAR;
185 tios.c_cc[VTIME] = 3;
186 tios.c_cc[VMIN] = LINE_LENGTH;
188 tcflush(fd, TCIFLUSH);
189 tcsetattr(fd, TCSANOW, &tios);
190 ioctl(fd, TIOCMBIC, &rts);
192 if (multimeter_read_value (&value) < -1)
199 INFO ("multimeter plugin: Device "
200 "found at %s", device);
206 ERROR ("multimeter plugin: No device found");
211 static void multimeter_submit (double value)
214 value_list_t vl = VALUE_LIST_INIT;
216 values[0].gauge = value;
220 vl.time = time (NULL);
221 strcpy (vl.host, hostname_g);
222 strcpy (vl.plugin, "multimeter");
224 plugin_dispatch_values ("multimeter", &vl);
227 static int multimeter_read (void)
234 if (multimeter_read_value (&value) != 0)
237 multimeter_submit (value);
239 } /* int multimeter_read */
241 static int multimeter_shutdown (void)
251 #endif /* MULTIMETER_HAVE_READ */
253 void module_register (void)
255 #if MULTIMETER_HAVE_READ
256 plugin_register_init ("multimeter", multimeter_init);
257 plugin_register_read ("multimeter", multimeter_read);
258 plugin_register_shutdown ("multimeter", multimeter_shutdown);
259 #endif /* MULTIMETER_HAVE_READ */
260 } /* void module_register */