Circuit Documentation

Summary of the Circuit

This circuit is designed to interface an Arduino UNO with a fingerprint scanner, a relay module, and a 12V solenoid lock, powered by a 12V power supply. The Arduino UNO acts as the central controller, managing the fingerprint scanner for user authentication and controlling the relay module, which in turn drives the solenoid lock. The relay module operates at 5V-30V and is used to switch the higher voltage required by the solenoid lock. The 12V power supply provides the necessary voltage for the solenoid lock and the common contact for the relay.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0-A5, SCL, SDA, AREF, D0-D13

Relay Module 5V-30V

• Description: A module that allows a low-power signal to switch a higher power circuit.
• Pins: Common contact, Normally open, Normally closed, Trigger, V-, V+

12V Solenoid Lock

• Description: An electromagnetic lock that operates at 12V.
• Pins: VCC, GND

Fingerprint Scanner

• Description: A biometric sensor for scanning fingerprints.
• Pins: VCC, TX, RX, GND

12V Power Supply

• Description: A power source that provides 12V output.
• Pins: +, -

Wiring Details

Arduino UNO

• 3.3V connected to Fingerprint Scanner VCC
• 5V connected to Relay Module V+
• GND connected to Relay Module V-, Fingerprint Scanner GND
• D2 connected to Fingerprint Scanner TX
• D3 connected to Fingerprint Scanner RX
• D4 connected to Relay Module Trigger

Relay Module 5V-30V

• V+ connected to Arduino UNO 5V
• V- connected to Arduino UNO GND
• Trigger connected to Arduino UNO D4
• Common contact connected to 12V Power Supply +
• Normally open connected to 12V Solenoid Lock VCC

12V Solenoid Lock

• VCC connected to Relay Module Normally open
• GND connected to 12V Power Supply -

Fingerprint Scanner

• VCC connected to Arduino UNO 3.3V
• TX connected to Arduino UNO D2
• RX connected to Arduino UNO D3
• GND connected to Arduino UNO GND

12V Power Supply

• • connected to Relay Module Common contact
• • connected to 12V Solenoid Lock GND

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 include specific functionality. It should be populated with the logic required to read the fingerprint scanner and control the relay module based on the authentication result.