- int retry = 3; /* sometimes we receive garbadge */
-
- do
- {
- struct timeval time_end;
-
- tcflush(fd, TCIFLUSH);
-
- if (gettimeofday (&time_end, NULL) < 0)
- {
- char errbuf[1024];
- ERROR ("ted plugin: gettimeofday failed: %s",
- sstrerror (errno, errbuf,
- sizeof (errbuf)));
- return (-1);
- }
- time_end.tv_sec++;
-
- while (1)
- {
- unsigned char buf[4096];
- unsigned char package_buffer[4096];
- char sResultByte;
- char sCmd[1];
- int status;
- int byte;
- int package_length=-1;
- int start_flag=0;
- int escape_flag=0;
- struct timeval timeout;
- struct timeval time_now;
- sCmd[0] = 0xAA;
-
- status = write (fd, sCmd, 1);
- INFO ("status of write %d",status);
- if (status < 0)
- {
- ERROR ("ted plugin: swrite failed.");
- return (-1);
- }
-
-
- if (gettimeofday (&time_now, NULL) < 0)
- {
- char errbuf[1024];
- ERROR ("ted plugin: "
- "gettimeofday failed: %s",
- sstrerror (errno, errbuf,
- sizeof (errbuf)));
- return (-1);
- }
- /*if (timeval_cmp (time_end, time_now, &timeout) < 0)
- break; */
-
- usleep(700000);
- status = select(fd+1, NULL, NULL, NULL, &timeout);
- INFO ("status 1 %d",status);
- status = 1;
-
-
-
- if (status > 0) /* usually we succeed */
- {
- status = read(fd, buf, 4096);
- INFO ("status of read %d",status);
-
- if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
- continue;
-
- for (byte=0; byte< status; byte++) {
- sResultByte = buf[byte];
- if (escape_flag) {
- escape_flag = 0;
- if ((sResultByte==ESCAPE) & (package_length > 0)){
- package_buffer[package_length] = ESCAPE;
- package_length++;
- }
- else if (sResultByte==PKT_BEGIN){
- start_flag = 1;
- package_length=0;
- }
- else if (sResultByte==PKT_END){
- package_buffer[package_length] = '\0';
- package_length++;
- }
- }
- else if (sResultByte == ESCAPE)
- escape_flag = 1;
- else if (package_length >= 0){
- package_buffer[package_length] = sResultByte;
- package_length++;
- }
-
- }
-
- INFO ("read package_length %d",package_length);
-
- if (package_length == 279)
- {
- *kv = ((package_buffer[248] * 256) + package_buffer[247])*10.0;
- INFO ("kv %f",*kv);
- *voltage = ((package_buffer[252] * 256) + package_buffer[251])/10.0;
- INFO ("voltage %f",*voltage);
- return (0); /* value received */
- }
- else
- INFO ("Not the correct package");
- usleep(700000);
- continue;
- //return (-1); /* Not pro package */
- }
- else if (!status) /* Timeout */
- {
- break;
- }
- else if ((status == -1) && ((errno == EAGAIN) || (errno == EINTR)))
- {
- usleep(700000);
- continue;
- }
- else /* status == -1 */
- {
- char errbuf[1024];
- ERROR ("ted plugin: "
- "select failed: %s",
- sstrerror (errno, errbuf, sizeof (errbuf)));
- break;
- }
- }
- } while (--retry);
-
- return (-2); /* no value received */
+ unsigned char receive_buffer[300];
+ unsigned char package_buffer[300];
+ char pkt_request[1] = {0xAA};
+ int package_buffer_pos;
+
+ fd_set input;
+ struct timeval timeout;
+
+ int end_flag;
+ int escape_flag;
+
+ int status;
+
+ assert (fd >= 0);
+
+ /* Initialize the input set*/
+ FD_ZERO (&input);
+ FD_SET (fd, &input);
+
+ /* Initialize timeout structure, set to 2 seconds */
+ memset (&timeout, 0, sizeof (timeout));
+ timeout.tv_sec = 2;
+ timeout.tv_usec = 0;
+
+ /* clear out anything in the buffer */
+ tcflush (fd, TCIFLUSH);
+
+ status = write (fd, pkt_request, sizeof(pkt_request));
+ if (status <= 0)
+ {
+ ERROR ("ted plugin: swrite failed.");
+ return (-1);
+ }
+
+ /* Loop until we find the end of the package */
+ end_flag = 0;
+ package_buffer_pos = 0;
+ while (end_flag == 0)
+ {
+ ssize_t receive_buffer_length;
+ ssize_t i;
+
+ /* check for timeout or input error*/
+ status = select (fd + 1, &input, NULL, NULL, &timeout);
+ if (status == 0) /* Timeout */
+ {
+ WARNING ("ted plugin: Timeout while waiting for file descriptor "
+ "to become ready.");
+ return (-1);
+ }
+ else if ((status < 0) && ((errno == EAGAIN) || (errno == EINTR)))
+ {
+ /* Some signal or something. Start over.. */
+ continue;
+ }
+ else if (status < 0)
+ {
+ char errbuf[1024];
+ ERROR ("ted plugin: select failed: %s",
+ sstrerror (errno, errbuf, sizeof (errbuf)));
+ return (-1);
+ }
+
+ receive_buffer_length = read (fd, receive_buffer, sizeof (receive_buffer));
+ if (receive_buffer_length < 0)
+ {
+ char errbuf[1024];
+ if ((errno == EAGAIN) || (errno == EINTR))
+ continue;
+ ERROR ("ted plugin: read(2) failed: %s",
+ sstrerror (errno, errbuf, sizeof (errbuf)));
+ return (-1);
+ }
+ else if (receive_buffer_length == 0)
+ {
+ /* Should we close the FD in this case? */
+ WARNING ("ted plugin: Received EOF from file descriptor.");
+ return (-1);
+ }
+ else if (receive_buffer_length > sizeof (receive_buffer))
+ {
+ ERROR ("ted plugin: read(2) returned invalid value %zi.",
+ receive_buffer_length);
+ return (-1);
+ }
+
+ /*
+ * packet filter loop
+ *
+ * Handle escape sequences in `receive_buffer' and put the
+ * result in `package_buffer'.
+ */
+ /* We need to see the begin sequence first. When we receive `ESCAPE
+ * PKT_BEGIN', we set `package_buffer_pos' to zero to signal that
+ * the beginning of the package has been found. */
+
+ escape_flag = 0;
+ for (i = 0; i < receive_buffer_length; i++)
+ {
+ /* Check if previous byte was the escape byte. */
+ if (escape_flag == 1)
+ {
+ escape_flag = 0;
+ /* escape escape = single escape */
+ if ((receive_buffer[i] == ESCAPE)
+ && (package_buffer_pos >= 0))
+ {
+ package_buffer[package_buffer_pos] = ESCAPE;
+ package_buffer_pos++;
+ }
+ else if (receive_buffer[i] == PKT_BEGIN)
+ {
+ package_buffer_pos = 0;
+ }
+ else if (receive_buffer[i] == PKT_END)
+ {
+ end_flag = 1;
+ break;
+ }
+ else
+ {
+ DEBUG ("ted plugin: Unknown escaped byte: %#x",
+ (unsigned int) receive_buffer[i]);
+ }
+ }
+ else if (receive_buffer[i] == ESCAPE)
+ {
+ escape_flag = 1;
+ }
+ /* if we are in a package add byte to buffer
+ * otherwise throw away */
+ else if (package_buffer_pos >= 0)
+ {
+ package_buffer[package_buffer_pos] = receive_buffer[i];
+ package_buffer_pos++;
+ }
+ } /* for (i = 0; i < receive_buffer_length; i++) */
+ } /* while (end_flag == 0) */
+
+ /* Check for errors inside the loop. */
+ if ((end_flag == 0) || (package_buffer_pos != EXPECTED_PACKAGE_LENGTH))
+ return (-1);
+
+ /*
+ * Power is at positions 247 and 248 (LSB first) in [10kW].
+ * Voltage is at positions 251 and 252 (LSB first) in [.1V].
+ *
+ * Power is in 10 Watt steps
+ * Voltage is in volts
+ */
+ *ret_power = 10.0 * (double) ((((int) package_buffer[248]) * 256)
+ + ((int) package_buffer[247]));
+ *ret_voltage = 0.1 * (double) ((((int) package_buffer[252]) * 256)
+ + ((int) package_buffer[251]));
+
+ /* success */
+ return (0);