openhab/sml/sml_server.c

// Copyright 2011 Juri Glass, Mathias Runge, Nadim El Sayed
// DAI-Labor, TU-Berlin
//
// This file is part of libSML.
// Thanks to Thomas Binder and Axel (tuxedo) for providing code how to
// print OBIS data (see transport_receiver()).
// https://community.openhab.org/t/using-a-power-meter-sml-with-openhab/21923
//
// libSML is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// libSML is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with libSML.  If not, see <http://www.gnu.org/licenses/>.

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <termios.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>
#include <sys/ioctl.h>

#include <sml/sml_file.h>
#include <sml/sml_transport.h>
#include <sml/sml_value.h>

int serial_port_open(const char* device) {
	int bits;
	struct termios config;
	memset(&config, 0, sizeof(config));

	if (!strcmp(device, "-"))
		return 0; // read stdin when "-" is given for the device

#ifdef O_NONBLOCK
	int fd = open(device, O_RDWR | O_NOCTTY | O_NONBLOCK);
#else
	int fd = open(device, O_RDWR | O_NOCTTY | O_NDELAY);
#endif
	if (fd < 0) {
		fprintf(stderr, "error: open(%s): %s\n", device, strerror(errno));
		return -1;
	}

	// set RTS
	ioctl(fd, TIOCMGET, &bits);
	bits |= TIOCM_RTS;
	ioctl(fd, TIOCMSET, &bits);

	tcgetattr(fd, &config);

	// set 8-N-1
	config.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR
			| ICRNL | IXON);
	config.c_oflag &= ~OPOST;
	config.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
	config.c_cflag &= ~(CSIZE | PARENB | PARODD | CSTOPB);
	config.c_cflag |= CS8;

	// set speed to 9600 baud
	cfsetispeed(&config, B9600);
	cfsetospeed(&config, B9600);

	tcsetattr(fd, TCSANOW, &config);
	return fd;
}

void transport_receiver(unsigned char *buffer, size_t buffer_len) {
   // Danke an Axel (tuxedo) für seinen Beispielcode
   int i;
   double value;
   sml_file *file = sml_file_parse(buffer + 8, buffer_len - 16);
   // the sml file is parsed now
   for (i = 0; i < file->messages_len; i++) {
      sml_message *message = file->messages[i];
      if (*message->message_body->tag == SML_MESSAGE_GET_LIST_RESPONSE) {
         sml_list *entry;
         sml_get_list_response *body;
         body = (sml_get_list_response *) message->message_body->data;
         for (entry = body->val_list; entry != NULL; entry = entry->next) {
            switch (entry->value->type) {
               case 0x51: value= *entry->value->data.int8; break;
               case 0x52: value= *entry->value->data.int16; break;
               case 0x54: value= *entry->value->data.int32; break;
               case 0x58: value= *entry->value->data.int64; break;
               case 0x61: value= *entry->value->data.uint8; break;
               case 0x62: value= *entry->value->data.uint16; break;
               case 0x64: value= *entry->value->data.uint32; break;
               case 0x68: value= *entry->value->data.uint64; break;
               default:
                  value = 0;
            }
            int scaler = (entry->scaler) ? *entry->scaler : 1;
            if (scaler==-1)
               value *= 0.0001;
               if (value) {
               printf("%d-%d:%d.%d.%d*%d#%.3f#\n",
               entry->obj_name->str[0], entry->obj_name->str[1],
               entry->obj_name->str[2], entry->obj_name->str[3],
               entry->obj_name->str[4], entry->obj_name->str[5], value);
            }
         }
         sml_file_free(file);
         exit(0); // processed first message - exit
      }
   }
}

int main(int argc, char *argv[]) {
	// this example assumes that a EDL21 meter sending SML messages via a
	// serial device. Adjust as needed.
	if (argc != 2) {
		printf("Usage: %s <device>\n", argv[0]);
		printf("device - serial device of connected power meter e.g. /dev/cu.usbserial, or - for stdin\n");
		exit(1); // exit here
	}

	// open serial port
	int fd = serial_port_open(argv[1]);
	if (fd < 0) {
		printf("Error: failed to open device (%s)\n", argv[1]);
		exit(3);
	}

	// listen on the serial device, this call is blocking.
	sml_transport_listen(fd, &transport_receiver);
	close(fd);

	return 0;
}