How to: get ID-20LA RFID and SIM900 to communicate with UNO (software serials)

hello forum
i working on project have send out sms when specific rfid tag scanned. have id-20la , sim900 shield hooked arduino uno, , both of them working fine on own. both rfid reader , gsm shield communicates uno via software-serial library.

this shield
http://imall.iteadstudio.com/im120417009.html

this current sketch. should have functioned way. "when 2 known tags gets scanned, send sms" - can't scan rfid's @ all, , no sms gets send.

code: [select]

#include <softwareserial.h>
#include "sim900.h"
#include "sms.h"
smsgsm sms;

softwareserial myserial(4,a2); // rx, tx
int rfidresetpin = 5;

//tags tilføjes her, de kan findes seriel monitor, når et tag scannes.
char tag1[13] = "01002dc7d03b";
char tag2[13] = "01002dc6678d";

void setup(){
 myserial.begin(9600);
 serial.begin(9600);
 gsm.begin(2400);

 pinmode(rfidresetpin, output);
 digitalwrite(rfidresetpin, high);
 
 myserial.listen();
}

void loop(){

 char tagstring[13];
 int index = 0;
 boolean reading = false;

 while(myserial.available()){  

   int readbyte = myserial.read(); //read next available byte

   if(readbyte == 2) reading = true; //begining of tag
   if(readbyte == 3) reading = false; //end of tag

   if(reading && readbyte != 2 && readbyte != 10 && readbyte != 13){
     //store tag
     tagstring[index] = readbyte;
     index ++;
   }
 }

 checktag(tagstring); //check if match
 cleartag(tagstring); //clear char of value
 resetreader(); //eset rfid reader
}

void checktag(char tag[]){
 ///////////////////////////////////
 //check read tag against known tags
 ///////////////////////////////////

 if(strlen(tag) == 0) return; //empty, no need contunue

 if(comparetag(tag, tag1)){ // if matched tag1, this
   sms.sendsms("12345678", "tag1"); //12345678 = phonenumber
 }
 else if(comparetag(tag, tag2)){ //if matched tag2, this
   sms.sendsms("12345678", "tag2");
 }
 else{
   serial.println(tag); //læs ukendte tags, og print serielt.
 }

}
void resetreader(){
 //reset læseren
 digitalwrite(rfidresetpin, low);
 digitalwrite(rfidresetpin, high);
 delay(150);
}

void cleartag(char one[]){
 //clear char array filling null - ascii 0
 //will think same tag has been read otherwise
 for(int = 0; < strlen(one); i++){
   one[i] = 0;
 }
}

boolean comparetag(char one[], char two[]){
 //compare 2 value see if same,
 if(strlen(one) == 0) return false; //empty

 for(int = 0; < 12; i++){
   if(one[i] != two[i]) return false;
 }

 return true; //no mismatches
}


i've read arduino can't handle 2 software serials running @ once, , therefore have use function ".listen" before communicating either rfid or sim900. @ bottom of void setup end "myserial.listen();" able scan tags. when known tag scanned, send sms, part of sketch:

code: [select]


if(comparetag(tag, tag1)){ // if matched tag1, this
gsm.listen();
sms.sendsms("12345678", "tag1"); //12345678 = phonenumber

i trying use "gsm.listen();" before sending message. problem theres no ".listen" function build sim900 library , therefore can't use it. if delete line "gsm.listen();" don't receive sms.

does know how can change serial rfid sim900 can send sms?

thank much
best regards

johannes

links shield details welcome. have better idea of may configurable , isn't.

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