UHF_RFID_KM900S_Simple_code_Software_Serial

/*
Connections:
------------------------------
Arduino Uno <---> RF-KLM900S
******************************
    3.3V    <--->     EN
    5V      <--->     5V
    GND     <--->     GND
    3       <--->     TTL_R
    2       <--->     TTL_T
------------------------------
*/
#include <SoftwareSerial.h>

SoftwareSerial SSerial(2, 3); // RX, TX

int numOfTags = 3;
//Single Read BB    00    22    00    00    22    7E
byte A[] = {0xBB, 0x00, 0x22, 0x00, 0x00, 0x22, 0x7E};

String TagNo[] = {"30 08 33 B2 DD D9 01 40 00 00 00 00",
                  "E2 80 68 94 00 00 50 20 91 08 58 7E",
                  "E2 80 68 94 00 00 50 20 91 08 58 88"
                 };

String TagID_RX = "";
static unsigned long lastTime = 0;

void setup() {
  SSerial.begin(115200);
  Serial.begin(115200);
  delay(2000);
}

void loop() {

  static String inputString;
  static unsigned long lastCharArrivalTime = 0;

  if (millis() - lastTime > 50 && inputString == "") {
    SSerial.write(A, sizeof(A));
    lastTime = millis();
  }

  if (SSerial.available())
  {
    byte incomingByte = SSerial.read();
    inputString += "0123456789ABCDEF"[incomingByte / 16];
    inputString += "0123456789ABCDEF"[incomingByte % 16];
    inputString += ' ';
    lastCharArrivalTime = millis();
  }

  if (lastCharArrivalTime != 0 && millis() - lastCharArrivalTime >= 10)
  {
    TagID_RX = inputString.substring(24, 59);
    for (int i = 0; i < numOfTags; i++) {
      if (!TagID_RX.compareTo(TagNo[i])) {
        Serial.print("Tag No [");
        Serial.print(i + 1);
        Serial.println("] Found.");
        Serial.println("------------------");
      }
    }
    inputString = "";
    lastCharArrivalTime = 0;
  }

}