Please help me in my issue , Hex value from my RFID Reader

[mot1639]

Hi all

I bought wavetrend RFID l-Rx201 , for long range RFID tag reader , and it small and work great in my PC.

now I come to integrated to micro controller (pic18f25k22) and use mikroc as a compiler .

the red box is one packet that shows the tag information and receiver info . under green line , 0x23 0x3A, it is tag Id which is 9018. and the 0x33 and 0x00 is a dont care value and it always should be same . the 0x6C it is signal strength and it always change depend on the tag if it is near to RFID receiver or far a way (it is from 0x00 to 0xFF. )

now i write simple code to chick if the RFID tag in area or not , if it is is blink LED , and if not, it keep led off , ( this code work fine) it similer for the one in bottom but remove the compare if and move LED to IF loop in i=4...

now I try to develop the code to switch on the LED if the RFID signal strength is bigger than 180 , that mean bigger than 0xB4 which mean the tag is near to RFID receiver for about 5m , if it is more than 5m (that mean it should be lower than 0xB4) it shold not give me LED ,

the problem now it always give LED if I am far or near to RFID ?????????? but if the tag not in area of the RFID receiver, it will keep the LED OFF.

now ,how can I mange to compare the hex value of the signal strength ????? if i wanted to be more than 0xb4 ?????

this is a code

unsigned long  i;
char tmp;
char hexStrn [4] = {0x23,0x3A,0x33,0x00};


void main() {
initialization();  // config the value
LED();
i=1;
found =1;

  while(1){
  if (UART1_Data_Ready()){
  tmp = UART1_Read();     // read the received data,
  if (found==0){
  if (tmp>0xB4){     [COLOR="#FF0000"]// compare the signal strength [/COLOR]
  LED();
  found=1;
  }
  }
      if(hexStrn[i] == tmp)
    {
     i++;
     if (i==4){
      i=0;
      found=0;
     }
    
    
    }
    else
    {
     i=0;
    }
}
}
}

please any one to advice , regards

 

[mot1639]

any hint please