Physical Controllers

Hand holding sensor

Measure the voltage - could be a chain of humans that hold hands, Arduino measure the voltage and smoothes it out with a capacitor. The LED is just to show the difference in voltage:

The Arduino connects to 5Volts, Ground and Analog 0

The Breadboard, purple wires are for holding in your hands. Capacitor to smooth out the voltage.

The code

void setup() {

 // initialize serial communication at 9600 bits per second:
 Serial.begin(9600);
 pinMode(LED_BUILTIN, OUTPUT);

}

void loop() {

 // read the input on analog pin 0:
 int sensorValue = analogRead(A0);
 // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
 float voltage = sensorValue * (5.0 / 1023.0);
 // print out the value you read:
 Serial.println(voltage);
 digitalWrite(LED_BUILTIN, HIGH);
 delay(voltage * 10);
 digitalWrite(LED_BUILTIN, LOW);
 delay(voltage * 10);

}

RFID Tag Reader

Can be used to read RFID Cards/ or write to them. Uses a ~3 Dollar RFID Reader (RC522) Worked best with Arduino Uno.

/*

* Initial Author: ryand1011 (https://github.com/ryand1011)
*
* Reads data written by a program such as "rfid_write_personal_data.ino"
*
* See: https://github.com/miguelbalboa/rfid/tree/master/examples/rfid_write_personal_data
*
* Uses MIFARE RFID card using RFID-RC522 reader
* Uses MFRC522 - Library
* -----------------------------------------------------------------------------------------
*             MFRC522      Arduino       Arduino   Arduino    Arduino          Arduino
*             Reader/PCD   Uno/101       Mega      Nano v3    Leonardo/Micro   Pro Micro
* Signal      Pin          Pin           Pin       Pin        Pin              Pin
* -----------------------------------------------------------------------------------------
* RST/Reset   RST          9             5         D9         RESET/ICSP-5     RST
* SPI SS      SDA(SS)      10            53        D10        10               10
* SPI MOSI    MOSI         11 / ICSP-4   51        D11        ICSP-4           16
* SPI MISO    MISO         12 / ICSP-1   50        D12        ICSP-1           14
* SPI SCK     SCK          13 / ICSP-3   52        D13        ICSP-3           15
*
* More pin layouts for other boards can be found here: https://github.com/miguelbalboa/rfid#pin-layout

• /

1. include <SPI.h>
2. include <MFRC522.h>

1. define RST_PIN 9 // Configurable, see typical pin layout above
2. define SS_PIN 10 // Configurable, see typical pin layout above
3. define LEDPIN 2
4. define BUZZPIN 3

MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance

//*****************************************************************************************// void setup() {

 Serial.begin(9600);                                           // Initialize serial communications with the PC
 SPI.begin();                                                  // Init SPI bus
 mfrc522.PCD_Init();                                              // Init MFRC522 card
 Serial.println(F("Read personal data on a MIFARE PICC:"));    //shows in serial that it is ready to read
   pinMode(LEDPIN, OUTPUT);
 pinMode(BUZZPIN, OUTPUT);

}

//*****************************************************************************************// void loop() {

 // Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
 MFRC522::MIFARE_Key key;
 for (byte i = 0; i < 6; i++) key.keyByte[i] = 0xFF;

 //some variables we need
 byte block;
 byte len;
 MFRC522::StatusCode status;

 //-------------------------------------------

 // Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
 if ( ! mfrc522.PICC_IsNewCardPresent()) {
   return;
 }

 // Select one of the cards
 if ( ! mfrc522.PICC_ReadCardSerial()) {
   return;
 }

 Serial.println("CARD ID:");
 digitalWrite(LEDPIN, HIGH);

 //mfrc522.PICC_DumpDetailsToSerial(&(mfrc522.uid)); //dump some details about the card
 

 for(int i=0; i < sizeof(mfrc522.uid.uidByte); i++){
   Serial.print(mfrc522.uid.uidByte[i]);
   tone(BUZZPIN, mfrc522.uid.uidByte[i]*60 + 100, 200);

   digitalWrite(LEDPIN, LOW);

   for(int j = 0; j < mfrc522.uid.uidByte[i]; j++){

     if(j > 10)
       continue;
       
     digitalWrite(LEDPIN, HIGH);
     delay(20); 
     digitalWrite(LEDPIN, LOW);
     delay(20);       
   }

   delay(300);  
 }

 Serial.println("\n");
 
 delay(1000);
 digitalWrite(LEDPIN, LOW);
 //mfrc522.PICC_DumpToSerial(&(mfrc522.uid));      //uncomment this to see all blocks in hex

 //-------------------------------------------

 return;

 Serial.print(F("Name: "));

 byte buffer1[18];

 block = 4;
 len = 18;

 //------------------------------------------- GET FIRST NAME
 status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 4, &key, &(mfrc522.uid)); //line 834 of MFRC522.cpp file
 if (status != MFRC522::STATUS_OK) {
   Serial.print(F("Authentication failed: "));
   Serial.println(mfrc522.GetStatusCodeName(status));
   return;
 }

 status = mfrc522.MIFARE_Read(block, buffer1, &len);
 if (status != MFRC522::STATUS_OK) {
   Serial.print(F("Reading failed: "));
   Serial.println(mfrc522.GetStatusCodeName(status));
   return;
 }

 //PRINT FIRST NAME
 for (uint8_t i = 0; i < 16; i++)
 {
   if (buffer1[i] != 32)
   {
     Serial.write(buffer1[i]);
   }
 }
 Serial.print(" ");

 //---------------------------------------- GET LAST NAME

 byte buffer2[18];
 block = 1;

 status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 1, &key, &(mfrc522.uid)); //line 834
 if (status != MFRC522::STATUS_OK) {
   Serial.print(F("Authentication failed: "));
   Serial.println(mfrc522.GetStatusCodeName(status));
   return;
 }

 status = mfrc522.MIFARE_Read(block, buffer2, &len);
 if (status != MFRC522::STATUS_OK) {
   Serial.print(F("Reading failed: "));
   Serial.println(mfrc522.GetStatusCodeName(status));
   return;
 }

 //PRINT LAST NAME
 for (uint8_t i = 0; i < 16; i++) {
   Serial.write(buffer2[i] );
 }

 //----------------------------------------

 Serial.println(F("\n**End Reading**\n"));

 delay(1000); //change value if you want to read cards faster

 mfrc522.PICC_HaltA();
 mfrc522.PCD_StopCrypto1();

}

SEEDUINO XIAO

A super small Arduino/Micropython device. About 15 Euros.

Connecting it to Arduino IDE: https://wiki.seeedstudio.com/Seeed_Arduino_Boards/