RHA

RaspberryPi hardware access from android app

Demo showing gpio read and write from android app (lineage os on raspberry pi)

app_demo.mp4

Arduino Code :

  #include <SPI.h>
  #include <MFRC522.h>

  #define SS_PIN 10
  #define RST_PIN 9
  MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.

  String msg ;
  String uid ;
  bool is_card_detected = false ;
  bool is_card_readable = false ;

  void setup() 
  {
    Serial.begin(9600);   // Initiate a serial communication
    SPI.begin();      // Initiate  SPI bus
    mfrc522.PCD_Init();   // Initiate MFRC522

  }
  void loop() 
  {
    // Look for new cards
    if ( ! mfrc522.PICC_IsNewCardPresent()) is_card_detected = false ;
    else is_card_detected = true ;

    // Select one of the cards
    if ( ! mfrc522.PICC_ReadCardSerial()) is_card_readable = false ;
    else is_card_readable = true ;


    //Show UID on serial monitor
    if (is_card_detected && is_card_readable){

      String content= "";
      byte letter;
      for (byte i = 0; i < mfrc522.uid.size; i++) 
      {
        content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
        content.concat(String(mfrc522.uid.uidByte[i], HEX));
      }
      content.toUpperCase();

      uid = content.substring(1) ;

      Serial.print(uid);
      Serial.println();
      delay(1000);

   }
  }

  /*
  void readSerialPort() {
    msg = "";
    if (Serial.available()) {
      delay(10);
      while (Serial.available() > 0) {
        msg += (char)Serial.read();
      }
      Serial.flush();
    }
  }*/

    /*if (content.substring(1) == "D9 50 09 E3") //change here the UID of the card/cards that you want to give access
    {
      Serial.println("Authorized access");
      Serial.println();
      delay(3000);
    }

   else   {
      Serial.println(" Access denied");
      delay(3000);
    }
  } */