Hola a todos.
Estoy intentando que una cadena string se vaya componiendo de caracteres.
Tengo:
char buf[15] = " ";
string id = "";
En un for, buf va teniendo estos valores en cada ejecución: 226, 128, 104, 016, 000, 000, 000, 057, 130, 242, 031, 163.
La idea es que la cadena id sea: 226128104016000000000057130242031163, pero no consigo hacerlo. Cuando más cerca he estado, id ha sido 226128104016, ha dejado de añadir a partir de los ceros.
No se muy bien cómo hacerlo.
Gracias de antemano.
Si no posteas el sketch que estas usando ,solo podemos hacer suposiciones de lo que podrias estar haciendo mal.
Una forma de hacerlo es con String usando concat para concatenar cadenas.
con cadenas la forma de hacerlo es con
char *strcat ( char *dest, const char *src );
ejemplo
#include <string.h>
char one[] = "Hello ";
char two[] = "world.";
char combined[32] = {0};
strcat(combined, one);
strcat(combined, two);
Muchas gracias Surbyte, con strcat si me ha juntado una cadena como quiero. Pero al hacer strcat, imprimo la cadena, y el programa se para. Este programa es para comunicarme con un lector RFID, debe quedarse leyendo, y es lo que hacía antes de poner strcat. Si comento strcat(combined, buf); el programa sigue leyendo tags RFID, que es lo que debe hacer.
/*
Reading multiple RFID tags, simultaneously!
By: Nathan Seidle @ SparkFun Electronics
Date: October 3rd, 2016
https://github.com/sparkfun/Simultaneous_RFID_Tag_Reader
Constantly reads and outputs any tags heard
If using the Simultaneous RFID Tag Reader (SRTR) shield, make sure the serial slide
switch is in the 'SW-UART' position
*/
#include <SoftwareSerial.h> //Used for transmitting to the device
#include <string.h>
SoftwareSerial softSerial(2, 3); //RX, TX
#include "SparkFun_UHF_RFID_Reader.h" //Library for controlling the M6E Nano module
RFID nano; //Create instance
char *strcat ( char *dest, const char *src );
char combined[32] = {0};
void setup()
{
Serial.begin(115200);
while (!Serial); //Wait for the serial port to come online
if (setupNano(38400) == false) //Configure nano to run at 38400bps
{
Serial.println(F("Module failed to respond. Please check wiring."));
while (1); //Freeze!
}
nano.setRegion(REGION_EUROPE); //Set to North America
nano.setReadPower(500); //5.00 dBm. Higher values may caues USB port to brown out
//Max Read TX Power is 27.00 dBm and may cause temperature-limit throttling
Serial.println(F("Press a key to begin scanning for tags."));
while (!Serial.available()); //Wait for user to send a character
Serial.read(); //Throw away the user's character
nano.startReading(); //Begin scanning for tags
}
void loop()
{
if (nano.check() == true) //Check to see if any new data has come in from module
{
byte responseType = nano.parseResponse(); //Break response into tag ID, RSSI, frequency, and timestamp
if (responseType == RESPONSE_IS_KEEPALIVE)
{
Serial.println(F("Scanning"));
}
else if (responseType == RESPONSE_IS_TAGFOUND)
{
//If we have a full record we can pull out the fun bits
int rssi = nano.getTagRSSI(); //Get the RSSI for this tag read
long freq = nano.getTagFreq(); //Get the frequency this tag was detected at
long timeStamp = nano.getTagTimestamp(); //Get the time this was read, (ms) since last keep-alive message
byte tagEPCBytes = nano.getTagEPCBytes(); //Get the number of bytes of EPC from response
//Print EPC bytes, this is a subsection of bytes from the response/msg array
Serial.print(F(" epc["));
for (byte x = 0 ; x < tagEPCBytes ; x++)
{
if (nano.msg[31 + x] < 0x10) Serial.print(F("0")); //Pretty print
char buf[15]=" ";
char* formato="%03i";
Serial.print(nano.msg[31 + x], HEX);
int i = nano.msg[31 + x];
sprintf(buf, formato, i);
strcat(combined, buf);
Serial.println();
}
Serial.print(F("ID ES: "));
Serial.println(combined);
Serial.print(F("]"));
Serial.println();
}
else if (responseType == ERROR_CORRUPT_RESPONSE)
{
Serial.println("Bad CRC");
}
else
{
//Unknown response
Serial.print("Unknown error");
}
}
}
//Gracefully handles a reader that is already configured and already reading continuously
//Because Stream does not have a .begin() we have to do this outside the library
boolean setupNano(long baudRate)
{
nano.begin(softSerial); //Tell the library to communicate over software serial port
//Test to see if we are already connected to a module
//This would be the case if the Arduino has been reprogrammed and the module has stayed powered
softSerial.begin(baudRate); //For this test, assume module is already at our desired baud rate
while(!softSerial); //Wait for port to open
//About 200ms from power on the module will send its firmware version at 115200. We need to ignore this.
while(softSerial.available()) softSerial.read();
nano.getVersion();
if (nano.msg[0] == ERROR_WRONG_OPCODE_RESPONSE)
{
//This happens if the baud rate is correct but the module is doing a ccontinuous read
nano.stopReading();
Serial.println(F("Module continuously reading. Asking it to stop..."));
delay(1500);
}
else
{
//The module did not respond so assume it's just been powered on and communicating at 115200bps
softSerial.begin(115200); //Start software serial at 115200
nano.setBaud(baudRate); //Tell the module to go to the chosen baud rate. Ignore the response msg
softSerial.begin(baudRate); //Start the software serial port, this time at user's chosen baud rate
}
//Test the connection
nano.getVersion();
if (nano.msg[0] != ALL_GOOD) return (false); //Something is not right
//The M6E has these settings no matter what
nano.setTagProtocol(); //Set protocol to GEN2
nano.setAntennaPort(); //Set TX/RX antenna ports to 1
return (true); //We are ready to rock
}
Solucionado
for (byte x = 0 ; x < tagEPCBytes ; x++)
{
if (nano.msg[31 + x] < 0x10) Serial.print(F("0")); //Pretty print
Serial.print(nano.msg[31 + x], HEX);
Serial.print(F(" "));
int i = nano.msg[31 + x];
sprintf(buf, formato, i);
strcat(combined, buf);
id += combined;
memset(combined, 0, sizeof(combined));
}
id es un String que he añadido ahora.
Muchas gracias surbyte