Now let's see the detailed wiring connection used in the RFID attendance tracker system, starting from the Arduino UNO. Digital Pin 11 MFRC522 MOSI SPI Data Out SPI communication Digital Pin 12 ...

An Arduino Uno (CH340G clone) reads temperature and humidity from a DHT11 sensor and computes 10+ environmental metrics (heat index, dew point, enthalpy, humidex, vapor pressures, etc.), outputting ...