3 * Copyright (C) 2009 Eric Reed
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 * Eric Reed <ericr at reedhome.net>
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
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
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.
42 #if HAVE_TERMIOS_H && HAVE_SYS_IOCTL_H
43 #include <sys/ioctl.h>
46 #error "No applicable input method."
49 #define EXPECTED_PACKAGE_LENGTH 278
51 #define PKT_BEGIN 0x04
54 #define DEFAULT_DEVICE "/dev/ttyUSB0"
56 static char *conf_device = NULL;
57 static int conf_retries = 0;
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;
72 /* Initialize timeout structure, set to 2 seconds */
73 struct timeval timeout = {.tv_sec = 2};
82 /* Initialize the input set*/
86 /* clear out anything in the buffer */
87 tcflush(fd, TCIFLUSH);
89 status = write(fd, pkt_request, sizeof(pkt_request));
91 ERROR("ted plugin: write failed.");
95 /* Loop until we find the end of the package */
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 */
105 WARNING("ted plugin: Timeout while waiting for file descriptor "
108 } else if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR))) {
109 /* Some signal or something. Start over.. */
111 } else if (status < 0) {
112 ERROR("ted plugin: select failed: %s", STRERRNO);
116 receive_buffer_length = read(fd, receive_buffer, sizeof(receive_buffer));
117 if (receive_buffer_length < 0) {
118 if ((errno == EAGAIN) || (errno == EINTR))
120 ERROR("ted plugin: read(2) failed: %s", STRERRNO);
122 } else if (receive_buffer_length == 0) {
123 /* Should we close the FD in this case? */
124 WARNING("ted plugin: Received EOF from file descriptor.");
126 } else if (((size_t)receive_buffer_length) > sizeof(receive_buffer)) {
127 ERROR("ted plugin: read(2) returned invalid value %zi.",
128 receive_buffer_length);
135 * Handle escape sequences in `receive_buffer' and put the
136 * result in `package_buffer'.
138 /* We need to see the begin sequence first. When we receive `ESCAPE
139 * PKT_BEGIN', we set `package_buffer_pos' to zero to signal that
140 * the beginning of the package has been found. */
143 for (ssize_t i = 0; i < receive_buffer_length; i++) {
144 /* Check if previous byte was the escape byte. */
145 if (escape_flag == 1) {
147 /* escape escape = single escape */
148 if ((receive_buffer[i] == ESCAPE) && (package_buffer_pos >= 0)) {
149 package_buffer[package_buffer_pos] = ESCAPE;
150 package_buffer_pos++;
151 } else if (receive_buffer[i] == PKT_BEGIN) {
152 package_buffer_pos = 0;
153 } else if (receive_buffer[i] == PKT_END) {
157 DEBUG("ted plugin: Unknown escaped byte: %#x",
158 (unsigned int)receive_buffer[i]);
160 } else if (receive_buffer[i] == ESCAPE) {
163 /* if we are in a package add byte to buffer
164 * otherwise throw away */
165 else if (package_buffer_pos >= 0) {
166 package_buffer[package_buffer_pos] = receive_buffer[i];
167 package_buffer_pos++;
169 } /* for (i = 0; i < receive_buffer_length; i++) */
170 } /* while (end_flag == 0) */
172 /* Check for errors inside the loop. */
173 if ((end_flag == 0) || (package_buffer_pos != EXPECTED_PACKAGE_LENGTH))
177 * Power is at positions 247 and 248 (LSB first) in [10kW].
178 * Voltage is at positions 251 and 252 (LSB first) in [.1V].
180 * Power is in 10 Watt steps
181 * Voltage is in volts
183 *ret_power = 10.0 * (double)((((int)package_buffer[248]) * 256) +
184 ((int)package_buffer[247]));
185 *ret_voltage = 0.1 * (double)((((int)package_buffer[252]) * 256) +
186 ((int)package_buffer[251]));
190 } /* int ted_read_value */
192 static int ted_open_device(void) {
194 struct termios options;
199 dev = DEFAULT_DEVICE;
200 if (conf_device != NULL)
203 fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
205 ERROR("ted plugin: Unable to open device %s.", dev);
209 /* Get the current options for the port... */
210 tcgetattr(fd, &options);
211 options.c_cflag = B19200 | CS8 | CSTOPB | CREAD | CLOCAL;
212 options.c_iflag = IGNBRK | IGNPAR;
215 options.c_cc[VTIME] = 20;
216 options.c_cc[VMIN] = 250;
218 /* Set the new options for the port... */
219 tcflush(fd, TCIFLUSH);
220 tcsetattr(fd, TCSANOW, &options);
222 INFO("ted plugin: Successfully opened %s.", dev);
224 } /* int ted_open_device */
226 static void ted_submit(const char *type, double value) {
227 value_list_t vl = VALUE_LIST_INIT;
229 vl.values = &(value_t){.gauge = value};
231 sstrncpy(vl.plugin, "ted", sizeof(vl.plugin));
232 sstrncpy(vl.type, type, sizeof(vl.type));
234 plugin_dispatch_values(&vl);
237 static int ted_config(const char *key, const char *value) {
238 if (strcasecmp("Device", key) == 0) {
240 conf_device = sstrdup(value);
241 } else if (strcasecmp("Retries", key) == 0) {
246 WARNING("ted plugin: Invalid retry count: %i", tmp);
251 ERROR("ted plugin: Unknown config option: %s", key);
256 } /* int ted_config */
258 static int ted_read(void) {
263 status = ted_open_device();
269 for (int i = 0; i <= conf_retries; i++) {
270 status = ted_read_value(&power, &voltage);
278 ted_submit("power", power);
279 ted_submit("voltage", voltage);
284 static int ted_shutdown(void) {
291 } /* int ted_shutdown */
293 void module_register(void) {
294 plugin_register_config("ted", ted_config, config_keys, config_keys_num);
295 plugin_register_read("ted", ted_read);
296 plugin_register_shutdown("ted", ted_shutdown);
297 } /* void module_register */