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 static data_source_t data_source[1] =
41 {"value", DS_TYPE_GAUGE, NAN, NAN}
44 static data_set_t data_set =
46 "multimeter", 1, data_source
49 #if MULTIMETER_HAVE_READ
52 static int multimeter_timeval_sub (struct timeval *tv1, struct timeval *tv2,
55 if ((tv1->tv_sec < tv2->tv_sec) ||
56 ((tv1->tv_sec == tv2->tv_sec) && (tv1->tv_usec < tv2->tv_usec)))
59 res->tv_sec = tv1->tv_sec - tv2->tv_sec;
60 res->tv_usec = tv1->tv_usec - tv2->tv_usec;
62 assert ((res->tv_sec > 0) || ((res->tv_sec == 0) && (res->tv_usec > 0)));
64 while (res->tv_usec < 0)
66 res->tv_usec += 1000000;
71 #define LINE_LENGTH 14
72 static int multimeter_read_value(double *value)
74 int retry = 3; /* sometimes we receive garbadge */
78 struct timeval time_end;
80 tcflush(fd, TCIFLUSH);
82 if (gettimeofday (&time_end, NULL) < 0)
84 syslog (LOG_ERR, "multimeter plugin: gettimeofday failed: %s",
92 char buf[LINE_LENGTH];
96 struct timeval timeout;
97 struct timeval time_now;
104 if (gettimeofday (&time_now, NULL) < 0)
106 syslog (LOG_ERR, "multimeter plugin: "
107 "gettimeofday failed: %s",
111 if (multimeter_timeval_sub (&time_end, &time_now, &timeout) == -1)
114 status = select(fd+1, &rfds, NULL, NULL, &timeout);
116 if (status > 0) /* usually we succeed */
118 status = read(fd, buf, LINE_LENGTH);
120 if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
123 /* Format: "DC 00.000mV \r" */
124 if (status > 0 && status == LINE_LENGTH)
126 *value = strtod(buf + 2, &range);
128 if ( range > (buf + 6) )
134 case 'p': *value *= 1.0E-12; break;
135 case 'n': *value *= 1.0E-9; break;
136 case 'u': *value *= 1.0E-6; break;
137 case 'm': *value *= 1.0E-3; break;
138 case 'k': *value *= 1.0E3; break;
139 case 'M': *value *= 1.0E6; break;
140 case 'G': *value *= 1.0E9; break;
144 return (-1); /* Overflow */
146 return (0); /* value received */
150 else if (!status) /* Timeout */
154 else if ((status == -1) && ((errno == EAGAIN) || (errno == EINTR)))
158 else /* status == -1 */
160 syslog (LOG_ERR, "multimeter plugin: "
168 return (-2); /* no value received */
169 } /* int multimeter_read_value */
171 static int multimeter_init (void)
174 char device[] = "/dev/ttyS ";
176 for (i = 0; i < 10; i++)
178 device[strlen(device)-1] = i + '0';
180 if ((fd = open(device, O_RDWR | O_NOCTTY)) > 0)
186 tios.c_cflag = B1200 | CS7 | CSTOPB | CREAD | CLOCAL;
187 tios.c_iflag = IGNBRK | IGNPAR;
190 tios.c_cc[VTIME] = 3;
191 tios.c_cc[VMIN] = LINE_LENGTH;
193 tcflush(fd, TCIFLUSH);
194 tcsetattr(fd, TCSANOW, &tios);
195 ioctl(fd, TIOCMBIC, &rts);
197 if (multimeter_read_value (&value) < -1)
204 syslog (LOG_INFO, "multimeter plugin: Device "
205 "found at %s", device);
211 syslog (LOG_ERR, "multimeter plugin: No device found");
216 static void multimeter_submit (double value)
219 value_list_t vl = VALUE_LIST_INIT;
221 values[0].gauge = value;
225 vl.time = time (NULL);
226 strcpy (vl.host, hostname_g);
227 strcpy (vl.plugin, "multimeter");
229 plugin_dispatch_values ("multimeter", &vl);
232 static int multimeter_read (void)
239 if (multimeter_read_value (&value) != 0)
242 multimeter_submit (value);
244 } /* int multimeter_read */
246 static int multimeter_shutdown (void)
256 #endif /* MULTIMETER_HAVE_READ */
258 void module_register (void)
260 plugin_register_data_set (&data_set);
262 #if MULTIMETER_HAVE_READ
263 plugin_register_init ("multimeter", multimeter_init);
264 plugin_register_read ("multimeter", multimeter_read);
265 plugin_register_shutdown ("multimeter", multimeter_shutdown);
266 #endif /* MULTIMETER_HAVE_READ */