From 83fa97fb9a18d8ed68582afe1cfc6f6cd0a83471 Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Sat, 7 Mar 2009 11:57:43 +0100 Subject: [PATCH] ted plugin: Fix some rough edges. --- src/ted.c | 393 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 220 insertions(+), 173 deletions(-) diff --git a/src/ted.c b/src/ted.c index 8242d00f..57c88898 100644 --- a/src/ted.c +++ b/src/ted.c @@ -47,211 +47,230 @@ # error "No applicable input method." #endif -#define PKT_LENGTH 278 -#define MAX_PKT 300 +#define EXPECTED_PACKAGE_LENGTH 278 #define ESCAPE 0x10 #define PKT_BEGIN 0x04 #define PKT_END 0x03 -#define DEFAULT_DEVICE "/dev/ttyUSB " +#define DEFAULT_DEVICE "/dev/ttyUSB0" + +static char *conf_device = NULL; +static int conf_retries = 0; -static char *device = NULL; static int fd = -1; -static const char *config_keys[] = { "Device" }; +static const char *config_keys[] = +{ + "Device", + "Retries" +}; static int config_keys_num = STATIC_ARRAY_SIZE (config_keys); -static int ted_read_value(double *kw, double *voltage) +static int ted_read_value(double *ret_power, double *ret_voltage) { - unsigned char sResult[MAX_PKT]; - unsigned char package_buffer[MAX_PKT]; - char sResultByte; - int status; - int byte; - int package_length; - int escape_flag; - int end_flag; - int sResultnum; - struct timeval timeout; + 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; - int retry = 3; /* sometimes we receive garbadge */ + assert (fd >= 0); /* Initialize the input set*/ - FD_ZERO(&input); - FD_SET(fd, &input); + FD_ZERO (&input); + FD_SET (fd, &input); - /* Initialize timout structure, set to 1 second */ - do + /* 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) { - timeout.tv_sec = 2; - timeout.tv_usec = 0; - escape_flag = 0; - end_flag = 0; - package_length = 0; - /* clear out anything in the buffer */ - tcflush(fd, TCIFLUSH); - - status = write (fd, pkt_request,sizeof(pkt_request)); - DEBUG ("status of write %d",status); - if (status < 0) + ERROR ("ted plugin: swrite failed."); + return (-1); + } + + /* Loop until we find the end of the package */ + end_flag = 0; + escape_flag = 0; + package_buffer_pos = -1; + 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 */ { - ERROR ("ted plugin: swrite failed."); + 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); } - - /* Loop until we find the end of the package */ - while (end_flag == 0) + receive_buffer_length = read (fd, receive_buffer, sizeof (receive_buffer)); + if (receive_buffer_length < 0) { - /* check for timeout or input error*/ - status = select(fd+1, &input, NULL, NULL, &timeout); - if (status == 0) /* Timeout */ - { - INFO ("Timeout"); - break; - } - else if ((status == -1) && ((errno == EAGAIN) || (errno == EINTR))) - { - DEBUG ("Not Ready"); + char errbuf[1024]; + if ((errno == EAGAIN) || (errno == EINTR)) continue; - } - else if (status == -1) - { - char errbuf[1024]; - ERROR ("ted plugin: select failed: %s", - sstrerror (errno, errbuf, sizeof (errbuf))); - break; - } + 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); + } + else if (receive_buffer_length < EXPECTED_PACKAGE_LENGTH) + { + WARNING ("ted plugin: read(2) returned %zi bytes, " + "but at least %i are necessary for a valid packet.", + receive_buffer_length, EXPECTED_PACKAGE_LENGTH); + return (-1); + } - else + /* + * 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. */ + package_buffer_pos = -1; + escape_flag = 0; + for (i = 0; i < receive_buffer_length; i++) + { + /* Check if previous byte was the escape byte. */ + if (escape_flag == 1) { - /* find out how may bytes are in the input buffer*/ - ioctl(fd, FIONREAD, &byte); - DEBUG ("bytes in buffer %d",byte); - if (byte <= 0) + escape_flag = 0; + /* escape escape = single escape */ + if ((receive_buffer[i] == ESCAPE) + && (package_buffer_pos >= 0)) { - continue; + package_buffer[package_buffer_pos] = ESCAPE; + package_buffer_pos++; } - - sResultnum = read(fd, sResult, MAX_PKT); - DEBUG ("bytes read %d",sResultnum); - - /* - * packet filter loop - */ - for (byte=0; byte< sResultnum; byte++) + else if (receive_buffer[i] == PKT_BEGIN) + { + package_buffer_pos = 0; + } + else if (receive_buffer[i] == PKT_END) + { + end_flag = 1; + break; + } + else { - sResultByte = sResult[byte]; - /* was byte before escape */ - if (escape_flag == 1) - { - escape_flag = 0; - /* escape escape = single escape */ - if ((sResultByte==ESCAPE) & (package_length > 0)) - { - package_buffer[package_length] = ESCAPE; - package_length++; - } - else if (sResultByte==PKT_BEGIN) - { - package_length=0; - } - else if (sResultByte==PKT_END) - { - end_flag = 1; - break; - } - } - else if (sResultByte == ESCAPE) - { - escape_flag = 1; - } - /* if we are in a package add byte to buffer - * otherwise throw away */ - else if (package_length >= 0) - { - package_buffer[package_length] = sResultByte; - package_length++; - } + DEBUG ("ted plugin: Unknown escaped byte: %#x", + (unsigned int) receive_buffer[i]); } } - } - DEBUG ("read package_length %d",package_length); - - if (package_length != PKT_LENGTH) - { - INFO ("Not the correct package"); - /* delay until next package is loaded into TED TED is updated once - * per second */ - usleep (1000000); - continue; - } - - /* part of the info in the package get KiloWatts at char 247 and 248 - * get Voltage at char 251 and 252 */ - *kw = ((package_buffer[248] * 256) + package_buffer[247])*10.0; - DEBUG ("kw %f",*kw); - *voltage = ((package_buffer[252] * 256) + package_buffer[251])/10.0; - DEBUG ("voltage %f",*voltage); - return (0); /* value received */ - + 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) */ - } while (--retry); + /* Check for errors inside the loop. */ + if (end_flag == 0) + return (-1); - return (-2); /* no value received */ + /* + * Power is at positions 247 and 248 (LSB first) in [10kW]. + * Voltage is at positions 251 and 252 (LSB first) in [.1V]. + * + * According to Eric's patch the power is in 10kW steps, but according to a + * Python module I've found, it's in 0.01kW == 10W. IMHO the Python scale + * is more realistic. -octo + */ + *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); } /* int ted_read_value */ -static int ted_init (void) +static int ted_open_device (void) { - int i; - double kw; - double voltage; + const char *dev; + struct termios options; - if (device == NULL) - { - device = DEFAULT_DEVICE; - } + if (fd >= 0) + return (0); - for (i = 0; i < 10; i++) + dev = DEFAULT_DEVICE; + if (conf_device != NULL) + dev = conf_device; + + fd = open (dev, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK); + if (fd < 0) { - device[strlen(device)-1] = i + '0'; + ERROR ("ted plugin: Unable to open device %s.", dev); + return (-1); + } - if ((fd = open(device, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK)) <= 0) - { - DEBUG ("No device at fd %d", fd); - close (fd); - continue; - } - struct termios options; - /* Get the current options for the port... */ - tcgetattr(fd, &options); - options.c_cflag = B19200 | CS8 | CSTOPB | CREAD | CLOCAL; - options.c_iflag = IGNBRK | IGNPAR; - options.c_oflag = 0; - options.c_lflag = 0; - options.c_cc[VTIME] = 20; - options.c_cc[VMIN] = 250; - - /* Set the new options for the port... */ - tcflush(fd, TCIFLUSH); - tcsetattr(fd, TCSANOW, &options); - - if (ted_read_value (&kw,&voltage) != 0) - { - DEBUG ("No device at fd %d", fd); - close (fd); - continue; - } + /* Get the current options for the port... */ + tcgetattr(fd, &options); + options.c_cflag = B19200 | CS8 | CSTOPB | CREAD | CLOCAL; + options.c_iflag = IGNBRK | IGNPAR; + options.c_oflag = 0; + options.c_lflag = 0; + options.c_cc[VTIME] = 20; + options.c_cc[VMIN] = 250; - INFO ("ted plugin: Device found at %s", device); - return (0); - } + /* Set the new options for the port... */ + tcflush(fd, TCIFLUSH); + tcsetattr(fd, TCSANOW, &options); - ERROR ("ted plugin: No device found"); - return (-1); -} + INFO ("ted plugin: Successfully opened %s.", dev); + return (0); +} /* int ted_open_device */ static void ted_submit (char *type_instance, double value) { @@ -272,29 +291,58 @@ static void ted_submit (char *type_instance, double value) static int ted_config (const char *key, const char *value) { - if (strcasecmp ("Device", key) != 0) + if (strcasecmp ("Device", key) == 0) + { + sfree (conf_device); + conf_device = sstrdup (value); + } + else if (strcasecmp ("Retries", key) == 0) { + int tmp; + + tmp = atoi (value); + if (tmp < 0) + { + WARNING ("ted plugin: Invalid retry count: %i", tmp); + return (1); + } + conf_retries = tmp; + } + else + { + ERROR ("ted plugin: Unknown config option: %s", key); return (-1); } - sfree (device); - device = sstrdup (value); return (0); } /* int ted_config */ static int ted_read (void) { - double kw; + double power; double voltage; + int status; + int i; - if (fd < 0) + status = ted_open_device (); + if (status != 0) return (-1); - if (ted_read_value (&kw,&voltage) != 0) + power = NAN; + voltage = NAN; + for (i = 0; i <= conf_retries; i++) + { + status = ted_read_value (&power, &voltage); + if (status == 0) + break; + } + + if (status != 0) return (-1); - ted_submit ("ted_kw", kw); - ted_submit ("ted_voltage", voltage); + ted_submit ("power", power); + ted_submit ("voltage", voltage); + return (0); } /* int ted_read */ @@ -313,7 +361,6 @@ void module_register (void) { plugin_register_config ("ted", ted_config, config_keys, config_keys_num); - plugin_register_init ("ted", ted_init); plugin_register_read ("ted", ted_read); plugin_register_shutdown ("ted", ted_shutdown); } /* void module_register */ -- 2.30.2