1f49b20cd80f963ecdb36df669900b5b523994e8
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
43 #include <sys/ioctl.h>
44 #include <termios.h>
45 #else
46 #error "No applicable input method."
47 #endif
49 #define EXPECTED_PACKAGE_LENGTH 278
50 #define ESCAPE 0x10
51 #define PKT_BEGIN 0x04
52 #define PKT_END 0x03
54 #define DEFAULT_DEVICE "/dev/ttyUSB0"
56 static char *conf_device = NULL;
57 static int conf_retries = 0;
59 static int fd = -1;
61 static const char *config_keys[] = {"Device", "Retries"};
62 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
64 static int ted_read_value(double *ret_power, double *ret_voltage) {
65 unsigned char receive_buffer[300];
66 unsigned char package_buffer[300];
67 unsigned char pkt_request[1] = {0xAA};
68 int package_buffer_pos;
70 fd_set input;
72 /* Initialize timeout structure, set to 2 seconds */
73 struct timeval timeout = {.tv_sec = 2};
75 int end_flag;
76 int escape_flag;
78 int status;
80 assert(fd >= 0);
82 /* Initialize the input set*/
83 FD_ZERO(&input);
84 FD_SET(fd, &input);
86 /* clear out anything in the buffer */
87 tcflush(fd, TCIFLUSH);
89 status = write(fd, pkt_request, sizeof(pkt_request));
90 if (status <= 0) {
91 ERROR("ted plugin: swrite failed.");
92 return (-1);
93 }
95 /* Loop until we find the end of the package */
96 end_flag = 0;
97 package_buffer_pos = 0;
98 while (end_flag == 0) {
99 ssize_t receive_buffer_length;
101 /* check for timeout or input error*/
102 status = select(fd + 1, &input, NULL, NULL, &timeout);
103 if (status == 0) /* Timeout */
104 {
105 WARNING("ted plugin: Timeout while waiting for file descriptor "
106 "to become ready.");
107 return (-1);
108 } else if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR))) {
109 /* Some signal or something. Start over.. */
110 continue;
111 } else if (status < 0) {
112 char errbuf[1024];
113 ERROR("ted plugin: select failed: %s",
114 sstrerror(errno, errbuf, sizeof(errbuf)));
115 return (-1);
116 }
118 receive_buffer_length = read(fd, receive_buffer, sizeof(receive_buffer));
119 if (receive_buffer_length < 0) {
120 char errbuf[1024];
121 if ((errno == EAGAIN) || (errno == EINTR))
122 continue;
123 ERROR("ted plugin: read(2) failed: %s",
124 sstrerror(errno, errbuf, sizeof(errbuf)));
125 return (-1);
126 } else if (receive_buffer_length == 0) {
127 /* Should we close the FD in this case? */
128 WARNING("ted plugin: Received EOF from file descriptor.");
129 return (-1);
130 } else if (((size_t)receive_buffer_length) > sizeof(receive_buffer)) {
131 ERROR("ted plugin: read(2) returned invalid value %zi.",
132 receive_buffer_length);
133 return (-1);
134 }
136 /*
137 * packet filter loop
138 *
139 * Handle escape sequences in `receive_buffer' and put the
140 * result in `package_buffer'.
141 */
142 /* We need to see the begin sequence first. When we receive `ESCAPE
143 * PKT_BEGIN', we set `package_buffer_pos' to zero to signal that
144 * the beginning of the package has been found. */
146 escape_flag = 0;
147 for (ssize_t i = 0; i < receive_buffer_length; i++) {
148 /* Check if previous byte was the escape byte. */
149 if (escape_flag == 1) {
150 escape_flag = 0;
151 /* escape escape = single escape */
152 if ((receive_buffer[i] == ESCAPE) && (package_buffer_pos >= 0)) {
153 package_buffer[package_buffer_pos] = ESCAPE;
154 package_buffer_pos++;
155 } else if (receive_buffer[i] == PKT_BEGIN) {
156 package_buffer_pos = 0;
157 } else if (receive_buffer[i] == PKT_END) {
158 end_flag = 1;
159 break;
160 } else {
161 DEBUG("ted plugin: Unknown escaped byte: %#x",
162 (unsigned int)receive_buffer[i]);
163 }
164 } else if (receive_buffer[i] == ESCAPE) {
165 escape_flag = 1;
166 }
167 /* if we are in a package add byte to buffer
168 * otherwise throw away */
169 else if (package_buffer_pos >= 0) {
170 package_buffer[package_buffer_pos] = receive_buffer[i];
171 package_buffer_pos++;
172 }
173 } /* for (i = 0; i < receive_buffer_length; i++) */
174 } /* while (end_flag == 0) */
176 /* Check for errors inside the loop. */
177 if ((end_flag == 0) || (package_buffer_pos != EXPECTED_PACKAGE_LENGTH))
178 return (-1);
180 /*
181 * Power is at positions 247 and 248 (LSB first) in [10kW].
182 * Voltage is at positions 251 and 252 (LSB first) in [.1V].
183 *
184 * Power is in 10 Watt steps
185 * Voltage is in volts
186 */
187 *ret_power = 10.0 * (double)((((int)package_buffer[248]) * 256) +
188 ((int)package_buffer[247]));
189 *ret_voltage = 0.1 * (double)((((int)package_buffer[252]) * 256) +
190 ((int)package_buffer[251]));
192 /* success */
193 return (0);
194 } /* int ted_read_value */
196 static int ted_open_device(void) {
197 const char *dev;
198 struct termios options;
200 if (fd >= 0)
201 return (0);
203 dev = DEFAULT_DEVICE;
204 if (conf_device != NULL)
205 dev = conf_device;
207 fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
208 if (fd < 0) {
209 ERROR("ted plugin: Unable to open device %s.", dev);
210 return (-1);
211 }
213 /* Get the current options for the port... */
214 tcgetattr(fd, &options);
215 options.c_cflag = B19200 | CS8 | CSTOPB | CREAD | CLOCAL;
216 options.c_iflag = IGNBRK | IGNPAR;
217 options.c_oflag = 0;
218 options.c_lflag = 0;
219 options.c_cc[VTIME] = 20;
220 options.c_cc[VMIN] = 250;
222 /* Set the new options for the port... */
223 tcflush(fd, TCIFLUSH);
224 tcsetattr(fd, TCSANOW, &options);
226 INFO("ted plugin: Successfully opened %s.", dev);
227 return (0);
228 } /* int ted_open_device */
230 static void ted_submit(const char *type, double value) {
231 value_list_t vl = VALUE_LIST_INIT;
233 vl.values = &(value_t){.gauge = value};
234 vl.values_len = 1;
235 sstrncpy(vl.plugin, "ted", sizeof(vl.plugin));
236 sstrncpy(vl.type, type, sizeof(vl.type));
238 plugin_dispatch_values(&vl);
239 }
241 static int ted_config(const char *key, const char *value) {
242 if (strcasecmp("Device", key) == 0) {
243 sfree(conf_device);
244 conf_device = sstrdup(value);
245 } else if (strcasecmp("Retries", key) == 0) {
246 int tmp;
248 tmp = atoi(value);
249 if (tmp < 0) {
250 WARNING("ted plugin: Invalid retry count: %i", tmp);
251 return (1);
252 }
253 conf_retries = tmp;
254 } else {
255 ERROR("ted plugin: Unknown config option: %s", key);
256 return (-1);
257 }
259 return (0);
260 } /* int ted_config */
262 static int ted_read(void) {
263 double power;
264 double voltage;
265 int status;
267 status = ted_open_device();
268 if (status != 0)
269 return (-1);
271 power = NAN;
272 voltage = NAN;
273 for (int i = 0; i <= conf_retries; i++) {
274 status = ted_read_value(&power, &voltage);
275 if (status == 0)
276 break;
277 }
279 if (status != 0)
280 return (-1);
282 ted_submit("power", power);
283 ted_submit("voltage", voltage);
285 return (0);
286 } /* int ted_read */
288 static int ted_shutdown(void) {
289 if (fd >= 0) {
290 close(fd);
291 fd = -1;
292 }
294 return (0);
295 } /* int ted_shutdown */
297 void module_register(void) {
298 plugin_register_config("ted", ted_config, config_keys, config_keys_num);
299 plugin_register_read("ted", ted_read);
300 plugin_register_shutdown("ted", ted_shutdown);
301 } /* void module_register */
303 /* vim: set sw=4 et : */