#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>

char *buf;
char in[256] = "";
ssize_t ret_out;
int fd = open ("/dev/ttyUSB0", O_RDWR | O_NOCTTY );
set_interface_attribs (fd, B2400, 0);  // set speed to 2,400 bps, 8n1 (no parity)
set_blocking (fd, 0 );                // set no blocking
strcpy( in, "UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
ret_out = write (fd, in, strlen(in));           // sent wakeup
usleep ((1000 + 25) * 100);             // sleep enough to transmit plus
buf = read_data( fd);
// Initialisiere MBus -> ACK mit 'E5'
in[0] = 0x10;
in[1] = 0x40; // Init MBus
in[2] = 0x00;
in[3] = 0x40; // Checksumme = in[1] + in [2]
in[4] = 0x16;
ret_out = write (fd, in, 5);           // sent
usleep ((1000 + 25) * 100);             // sleep enough to transmit plus
buf = read_data( fd);
if (buf[5] == 0xE5)
{ 
// Get Data from MBus
in[0] = 0x10;
in[1] = 0x5B;  // GetData
in[2] = 0x00;
in[3] = 0x5B;   // Checksumme = in[1] + in [2]
in[4] = 0x16;
ret_out = write (fd, in, 5);
usleep ((1000 + 25) * 100);             // sleep enough to transmit plus
buf = read_data( fd);
// Zaehlerstand
double waerme = ((double) toInt(&buf[26])) + (100.0 * (double) toInt(&buf[27])) + (1000.0 * (double) toInt(&buf[28])) + (10000.0 * (double) toInt(&buf[29]));
//aktuelle Leistung
double leistung = ((double) toInt(&buf[44])) + (100.0 * (double) toInt(&buf[45])) + (1000.0 * (double) toInt(&buf[46])) + (10000.0 * (double) toInt(&buf[47]));
}

int toInt( char *in ) {

char out[2];
int iOut = 0;
sprintf(out, "%02x", in[0]);
iOut = atoi(out);
return iOut;
}