Input Device

For this weeks assignment I had to add an sensor to my board and read it afterwards.

In order of my final project which is a elecric gokart I wanted to use an rfid scanner to authenticate myself, so I could use it for my final project afterwards. I've made a board design using the atmega328p chipset, to attach my rfid scanner to.

To attach my rfid scanner direclty to my board I have exposed the programming pins (miso,mosi,sck) and the other pins whoich are required to use the rfid scanner. On my board I have routed the required pins in the right order so that I was able to attach the rfid scanner directly to the board without using jumper cables.

I have connected the rfid scanner to my board according to this schematic.

the atmega328p which can also be found on the arduino uno, has of course ,the same pinout as the arduino uno.

My code is a simple authentication using the id of rfid chips and storing them into arrays, to authenticate I compare the scanned tag with the id of the master key.

		#include >SPI.h≷
#include >MFRC522.h≷
 
constexpr uint8_t RST_PIN = 9;     // Configurable, see typical pin layout above
constexpr uint8_t SS_PIN = 10;     // Configurable, see typical pin layout above
 
MFRC522 rfid(SS_PIN, RST_PIN); // Instance of the class
 
MFRC522::MIFARE_Key key; 
 
// Init array that will store new NUID 
byte nuidPICC[4];


void setup() { 
  Serial.begin(115200);
  SPI.begin(); // Init SPI bus
  rfid.PCD_Init(); // Init MFRC522 
 
  for (byte i = 0; i < 6; i++) {
    key.keyByte[i] = 0xFF;
  }
 
 
}
 
void loop() {
 
  // Look for new cards
  if ( ! rfid.PICC_IsNewCardPresent())
    return;
 
  // Verify if the NUID has been readed
  if ( ! rfid.PICC_ReadCardSerial())
    return;
 
 // Serial.print(F("PICC type: "));
  MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak);
  //Serial.println(rfid.PICC_GetTypeName(piccType));
 
  // Check is the PICC of Classic MIFARE type
  if (piccType != MFRC522::PICC_TYPE_MIFARE_MINI &&  
    piccType != MFRC522::PICC_TYPE_MIFARE_1K &&
    piccType != MFRC522::PICC_TYPE_MIFARE_4K) {
    //Serial.println(F("Your tag is not of type MIFARE Classic."));
    return;
  }
  //Check if the scanned tag has the same NUID by comparing the array with the actual numbers 
  if (rfid.uid.uidByte[0] == 201 && 
    rfid.uid.uidByte[1] == 211 && 
    rfid.uid.uidByte[2] == 124 && 
    rfid.uid.uidByte[3] == 91 ) {
 //print hello message   
    Serial.println(F("Hello Master!"));
 
    // Store NUID into nuidPICC array
    for (byte i = 0; i < 4; i++) {
      nuidPICC[i] = rfid.uid.uidByte[i];
    }
   
  
  }
  

//Check if the scanned tag has the same NUID by comparing the array with the actual numbers
 else if (rfid.uid.uidByte[0] == 36 && 
    rfid.uid.uidByte[1] == 159 && 
    rfid.uid.uidByte[2] == 223 && 
    rfid.uid.uidByte[3] == 43 ) {

//Print hello message    
    Serial.println(F("Hello Mr.Rustamov!"));
 
    // Store NUID into nuidPICC array
    for (byte i = 0; i < 4; i++) {
      nuidPICC[i] = rfid.uid.uidByte[i];
    }
   
  
  }
//Check if scanned tag has a difference to the master tags
  else if (rfid.uid.uidByte[0] != 201 || 
    rfid.uid.uidByte[0] != 36 || 
    rfid.uid.uidByte[1] != 211 || 
    rfid.uid.uidByte[1] != 159 ||
    rfid.uid.uidByte[2] != 124 ||
    rfid.uid.uidByte[2] != 223 ||
    rfid.uid.uidByte[3] != 91 ||
    rfid.uid.uidByte[3] != 43
                                  ) {
     

    // Store NUID into nuidPICC array
    for (byte i = 0; i < 4; i++) {
      nuidPICC[i] = rfid.uid.uidByte[i];
    }
 
  
    
    
    //Giving an error message because the tag is not a master tag
    Serial.println(F("Invalid Card!"));
    }
  //Scanning a new tag
  if (rfid.uid.uidByte[0] != nuidPICC[0] || 
    rfid.uid.uidByte[1] != nuidPICC[1] || 
    rfid.uid.uidByte[2] != nuidPICC[2] || 
    rfid.uid.uidByte[3] != nuidPICC[3] ) {
     

    // Store NUID into nuidPICC array
    for (byte i = 0; i < 4; i++) {
      nuidPICC[i] = rfid.uid.uidByte[i];
    }
    }
  // Halt PICC
  rfid.PICC_HaltA();
 
  // Stop encryption on PCD
  rfid.PCD_StopCrypto1();
}
 
 
/**
 * Helper routine to dump a byte array as hex values to Serial. 
 */
void printHex(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], HEX);
  }
}
 
/**
 * Helper routine to dump a byte array as dec values to Serial.
 */
void printDec(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], DEC);
  }
}

My code is based on the tutorial of Circuits4You.

For visualizing purposes I will show you my phyton interface which I made for the Interface and application programming week.

In addition to that I have designed another board based on the atmega 328p chipset. I wanted to build a electric longboard which I will accelerate using a pressure sensor.

If you would like to have an introduction to electronics design/production check my electronics design and my electronics production assignment.

to attach the pressure sensor, I have followed this schematik. It is important that you use a 10k ohm resistor between the analog pin and ground to protect the sensor from overvoltage.

The pressure sensor returns an analog signal which I can use to control an brushless motor. I wrote a small code to do that.

    

const int motor = 11;   //defining motor pin
const int pressurePin = A0;   //defining pressure sensor pin(has to be analog pin)
int value = 0;    //creating value for the sensor
int mappedValue = 0;
void setup() {
pinMode(motor,OUTPUT);    //setting the motorpin as an output pin
Serial.begin(9600);

}

void loop() {
value = analogRead(pressurePin);    //giving value the output of the analog sensor
mappedValue = map(value, 0, 800, 100, 254);
//Serial.println(value);
Serial.println(mappedValue);


analogWrite(motor, mappedValue);//give motorcontroller the value of the sensor


}

In the following video you can see a quick demonstration of the brushless motor working using the pressure sensor