1 /**
2 * collectd - src/ted.c
3 * Copyright (C) 2009 Eric Reed
4 *
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.
9 *
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.
14 *
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
18 *
19 * Authors:
20 * Eric Reed <ericr at reedhome.net>
21 *
22 * This is a collectd module for The Energy Detective: A low-cost whole
23 * house energy monitoring system. For more information on TED, see
24 * http://theenergydetective.com
25 *
26 * This module was not created by Energy, Inc. nor is it supported by
27 * them in any way. It was created using information from two sources:
28 * David Satterfield's TED module for Misterhouse, and Micah Dowty's TED
29 * Python Module.
30 *
31 * This has only tested with the model 1001 RDU, with
32 * firmware version 9.01U. The USB port is uses the very common FTDI
33 * USB-to-serial chip, so the RDU will show up as a serial device on
34 * Windows, Mac OS, or Linux.
35 **/
37 #include "collectd.h"
39 #include "common.h"
40 #include "plugin.h"
42 #if HAVE_TERMIOS_H && HAVE_SYS_IOCTL_H && HAVE_MATH_H
43 #include <math.h>
44 #include <sys/ioctl.h>
45 #include <termios.h>
46 #else
47 #error "No applicable input method."
48 #endif
50 #define EXPECTED_PACKAGE_LENGTH 278
51 #define ESCAPE 0x10
52 #define PKT_BEGIN 0x04
53 #define PKT_END 0x03
55 #define DEFAULT_DEVICE "/dev/ttyUSB0"
57 static char *conf_device = NULL;
58 static int conf_retries = 0;
60 static int fd = -1;
62 static const char *config_keys[] = {"Device", "Retries"};
63 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
65 static int ted_read_value(double *ret_power, double *ret_voltage) {
66 unsigned char receive_buffer[300];
67 unsigned char package_buffer[300];
68 unsigned char pkt_request[1] = {0xAA};
69 int package_buffer_pos;
71 fd_set input;
73 /* Initialize timeout structure, set to 2 seconds */
74 struct timeval timeout = {.tv_sec = 2};
76 int end_flag;
77 int escape_flag;
79 int status;
81 assert(fd >= 0);
83 /* Initialize the input set*/
84 FD_ZERO(&input);
85 FD_SET(fd, &input);
87 /* clear out anything in the buffer */
88 tcflush(fd, TCIFLUSH);
90 status = write(fd, pkt_request, sizeof(pkt_request));
91 if (status <= 0) {
92 ERROR("ted plugin: swrite failed.");
93 return (-1);
94 }
96 /* Loop until we find the end of the package */
97 end_flag = 0;
98 package_buffer_pos = 0;
99 while (end_flag == 0) {
100 ssize_t receive_buffer_length;
102 /* check for timeout or input error*/
103 status = select(fd + 1, &input, NULL, NULL, &timeout);
104 if (status == 0) /* Timeout */
105 {
106 WARNING("ted plugin: Timeout while waiting for file descriptor "
107 "to become ready.");
108 return (-1);
109 } else if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR))) {
110 /* Some signal or something. Start over.. */
111 continue;
112 } else if (status < 0) {
113 char errbuf[1024];
114 ERROR("ted plugin: select failed: %s",
115 sstrerror(errno, errbuf, sizeof(errbuf)));
116 return (-1);
117 }
119 receive_buffer_length = read(fd, receive_buffer, sizeof(receive_buffer));
120 if (receive_buffer_length < 0) {
121 char errbuf[1024];
122 if ((errno == EAGAIN) || (errno == EINTR))
123 continue;
124 ERROR("ted plugin: read(2) failed: %s",
125 sstrerror(errno, errbuf, sizeof(errbuf)));
126 return (-1);
127 } else if (receive_buffer_length == 0) {
128 /* Should we close the FD in this case? */
129 WARNING("ted plugin: Received EOF from file descriptor.");
130 return (-1);
131 } else if (((size_t)receive_buffer_length) > sizeof(receive_buffer)) {
132 ERROR("ted plugin: read(2) returned invalid value %zi.",
133 receive_buffer_length);
134 return (-1);
135 }
137 /*
138 * packet filter loop
139 *
140 * Handle escape sequences in `receive_buffer' and put the
141 * result in `package_buffer'.
142 */
143 /* We need to see the begin sequence first. When we receive `ESCAPE
144 * PKT_BEGIN', we set `package_buffer_pos' to zero to signal that
145 * the beginning of the package has been found. */
147 escape_flag = 0;
148 for (ssize_t i = 0; i < receive_buffer_length; i++) {
149 /* Check if previous byte was the escape byte. */
150 if (escape_flag == 1) {
151 escape_flag = 0;
152 /* escape escape = single escape */
153 if ((receive_buffer[i] == ESCAPE) && (package_buffer_pos >= 0)) {
154 package_buffer[package_buffer_pos] = ESCAPE;
155 package_buffer_pos++;
156 } else if (receive_buffer[i] == PKT_BEGIN) {
157 package_buffer_pos = 0;
158 } else if (receive_buffer[i] == PKT_END) {
159 end_flag = 1;
160 break;
161 } else {
162 DEBUG("ted plugin: Unknown escaped byte: %#x",
163 (unsigned int)receive_buffer[i]);
164 }
165 } else if (receive_buffer[i] == ESCAPE) {
166 escape_flag = 1;
167 }
168 /* if we are in a package add byte to buffer
169 * otherwise throw away */
170 else if (package_buffer_pos >= 0) {
171 package_buffer[package_buffer_pos] = receive_buffer[i];
172 package_buffer_pos++;
173 }
174 } /* for (i = 0; i < receive_buffer_length; i++) */
175 } /* while (end_flag == 0) */
177 /* Check for errors inside the loop. */
178 if ((end_flag == 0) || (package_buffer_pos != EXPECTED_PACKAGE_LENGTH))
179 return (-1);
181 /*
182 * Power is at positions 247 and 248 (LSB first) in [10kW].
183 * Voltage is at positions 251 and 252 (LSB first) in [.1V].
184 *
185 * Power is in 10 Watt steps
186 * Voltage is in volts
187 */
188 *ret_power = 10.0 * (double)((((int)package_buffer[248]) * 256) +
189 ((int)package_buffer[247]));
190 *ret_voltage = 0.1 * (double)((((int)package_buffer[252]) * 256) +
191 ((int)package_buffer[251]));
193 /* success */
194 return (0);
195 } /* int ted_read_value */
197 static int ted_open_device(void) {
198 const char *dev;
199 struct termios options;
201 if (fd >= 0)
202 return (0);
204 dev = DEFAULT_DEVICE;
205 if (conf_device != NULL)
206 dev = conf_device;
208 fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
209 if (fd < 0) {
210 ERROR("ted plugin: Unable to open device %s.", dev);
211 return (-1);
212 }
214 /* Get the current options for the port... */
215 tcgetattr(fd, &options);
216 options.c_cflag = B19200 | CS8 | CSTOPB | CREAD | CLOCAL;
217 options.c_iflag = IGNBRK | IGNPAR;
218 options.c_oflag = 0;
219 options.c_lflag = 0;
220 options.c_cc[VTIME] = 20;
221 options.c_cc[VMIN] = 250;
223 /* Set the new options for the port... */
224 tcflush(fd, TCIFLUSH);
225 tcsetattr(fd, TCSANOW, &options);
227 INFO("ted plugin: Successfully opened %s.", dev);
228 return (0);
229 } /* int ted_open_device */
231 static void ted_submit(const char *type, double value) {
232 value_list_t vl = VALUE_LIST_INIT;
234 vl.values = &(value_t){.gauge = value};
235 vl.values_len = 1;
236 sstrncpy(vl.plugin, "ted", sizeof(vl.plugin));
237 sstrncpy(vl.type, type, sizeof(vl.type));
239 plugin_dispatch_values(&vl);
240 }
242 static int ted_config(const char *key, const char *value) {
243 if (strcasecmp("Device", key) == 0) {
244 sfree(conf_device);
245 conf_device = sstrdup(value);
246 } else if (strcasecmp("Retries", key) == 0) {
247 int tmp;
249 tmp = atoi(value);
250 if (tmp < 0) {
251 WARNING("ted plugin: Invalid retry count: %i", tmp);
252 return (1);
253 }
254 conf_retries = tmp;
255 } else {
256 ERROR("ted plugin: Unknown config option: %s", key);
257 return (-1);
258 }
260 return (0);
261 } /* int ted_config */
263 static int ted_read(void) {
264 double power;
265 double voltage;
266 int status;
268 status = ted_open_device();
269 if (status != 0)
270 return (-1);
272 power = NAN;
273 voltage = NAN;
274 for (int i = 0; i <= conf_retries; i++) {
275 status = ted_read_value(&power, &voltage);
276 if (status == 0)
277 break;
278 }
280 if (status != 0)
281 return (-1);
283 ted_submit("power", power);
284 ted_submit("voltage", voltage);
286 return (0);
287 } /* int ted_read */
289 static int ted_shutdown(void) {
290 if (fd >= 0) {
291 close(fd);
292 fd = -1;
293 }
295 return (0);
296 } /* int ted_shutdown */
298 void module_register(void) {
299 plugin_register_config("ted", ted_config, config_keys, config_keys_num);
300 plugin_register_read("ted", ted_read);
301 plugin_register_shutdown("ted", ted_shutdown);
302 } /* void module_register */
304 /* vim: set sw=4 et : */