Circuit Documentation

Summary

This circuit integrates various components with an Arduino UNO microcontroller to perform tasks involving RFID reading, temperature sensing, light detection, and signaling through LEDs and buzzers. The circuit is powered by a 9V battery and utilizes transistors and resistors to control the flow and distribution of power to different components.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

Photocell (LDR)

• A light-dependent resistor whose resistance varies with the amount of light it is exposed to.

RFID-RC522

• An RFID reader/writer module that operates at 13.56 MHz.

TEMP

• A temperature sensor component.

BC547 Transistor

• A general-purpose NPN bipolar junction transistor used for switching and amplification.

Battery 9V

• A standard 9-volt battery used to power the circuit.

Resistor

• A passive two-terminal electrical component that implements electrical resistance as a circuit element.

LED: Two Pin (red/white)

• A light-emitting diode that emits red or white light when powered.

Buzzer

• An audio signaling device that can be mechanical, electromechanical, or piezoelectric.

Wiring Details

Arduino UNO

• 3.3V connected to RFID-RC522 VCC (3.3V)
• 5V connected to TEMP 5V
• GND connected to buzzer GND, LED (red) cathode, TEMP GND, RFID-RC522 GND
• D13 connected to RFID-RC522 SCK
• D12 connected to RFID-RC522 MISO
• D11 connected to RFID-RC522 MOSI
• D10 connected to RFID-RC522 SDA
• D9 connected to RFID-RC522 RST
• D8 connected to TEMP D3
• D5 connected to buzzer PIN
• D4 connected to LED (red) anode

Photocell (LDR)

• pin 0 connected to 9V Battery (-) and LED (white) cathode
• pin 1 connected to BC547 Transistor Base and buzzer GND

RFID-RC522

• Connections to Arduino UNO as detailed above.

TEMP

• 5V and GND connected to Arduino UNO 5V and GND respectively
• D3 connected to Arduino UNO D8

BC547 Transistor

• Base connected to Photocell (LDR) pin 1 and Resistor pin2
• Collector connected to 9V Battery (+) and Resistor pin1
• Emitter connected to LED (white) anode and buzzer PIN

Battery 9V

• VCC connected to BC547 Transistor Collector
• GND connected to Photocell (LDR) pin 0

Resistor

• pin1 connected to BC547 Transistor Collector
• pin2 connected to BC547 Transistor Base

LED: Two Pin (red/white)

• cathode connected to Arduino UNO GND and Photocell (LDR) pin 0
• anode connected to Arduino UNO D4 and BC547 Transistor Emitter

Buzzer

• PIN connected to Arduino UNO D5 and BC547 Transistor Emitter
• GND connected to Arduino UNO GND and Photocell (LDR) pin 1

Documented Code

Arduino UNO Code (sketch.ino)

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Note: The provided code is a template and does not contain any functional code. It needs to be populated with the logic to control the RFID-RC522, read the TEMP sensor, detect light with the LDR, and activate the LEDs and buzzers accordingly.