Circuit Documentation

Summary of the Circuit

This circuit is designed to interface an Arduino Micro with a temperature sensor (LM35), a Bluetooth module (HC-05), a 12V single-channel relay, and a 220V fan. The circuit includes a power transformer and a bridge rectifier to convert AC supply to DC, and a 7805 voltage regulator to provide a stable 5V supply to the components. The Arduino Micro is programmed to interact with the HC-05 Bluetooth module for wireless communication and to read temperature data from the LM35 sensor. The relay is used to control the 220V fan based on the temperature readings or commands received via Bluetooth.

Component List

Arduino Micro (Rev3)

• Microcontroller board based on the ATmega32U4
• Features digital I/O pins, analog inputs, a crystal oscillator, a micro USB connection, an ICSP header, and a reset button

Temperature Sensor (LM35)

• Precision integrated-circuit temperature sensor
• Linear voltage output proportional to the Celsius temperature

12V Single Channel Relay

• Electromechanical switch with an activation coil rated at 12V
• Features Normally Open (NO), Normally Closed (NC), and Common (COM) terminals

Power Transformer

• Device that transfers electrical energy between two or more circuits through electromagnetic induction
• Designed for stepping down the AC supply voltage to a lower voltage

Bridge Rectifier

• An arrangement of diodes in a bridge circuit configuration that provides the same polarity of output for either polarity of input
• Used to convert AC input to DC output

Electrolytic Capacitor

• A capacitor with a capacitance value of 1 microfarad
• Used for filtering and smoothing the rectified DC voltage

7805 Voltage Regulator

• A fixed output voltage regulator that provides a regulated 5V output
• Features input, ground, and output pins

AC Supply

• The primary source of power for the circuit
• Provides alternating current (AC) voltage

220V Fan

• An electric fan designed to operate at 220V AC
• Used for cooling purposes

HC-05 Bluetooth Module

• A wireless communication module that allows for Bluetooth connectivity
• Features pins for enabling, power supply, ground, transmit, and receive functions

Wiring Details

Arduino Micro (Rev3)

• D1/TX connected to HC-05 RXD
• D0/RX connected to HC-05 TXD
• GND connected to the common ground net
• D3/SCL connected to Relay IN
• 5V connected to the 5V net supplying power to Relay VCC, HC-05 VCC, 7805 Vout, and LM35 +Vs
• A1 connected to LM35 Vout

Temperature Sensor (LM35)

• +Vs connected to the 5V net
• Vout connected to Arduino Micro A1
• GND connected to the common ground net

12V Single Channel Relay

• GND connected to the common ground net
• IN connected to Arduino Micro D3/SCL
• VCC connected to the 5V net
• COM connected to Power Transformer 2 - Primary
• NO connected to 220V Fan L

Power Transformer

• 1 - Primary connected to AC Supply +ve
• 2 - Primary connected to Relay COM
• 3 - Secondary connected to Bridge Rectifier Source_in-
• 4 - Secondary connected to Bridge Rectifier source_in+

Bridge Rectifier

• Source_in- connected to Power Transformer 3 - Secondary
• source_in+ connected to Power Transformer 4 - Secondary
• source_out- connected to the common ground net
• source_out+ connected to the positive voltage net

Electrolytic Capacitor

• - connected to the common ground net
• + connected to the positive voltage net

7805 Voltage Regulator

• Vin connected to the positive voltage net
• Gnd connected to the common ground net
• Vout connected to the 5V net

AC Supply

• +ve connected to Power Transformer 1 - Primary
• -ve connected to Relay COM

220V Fan

• L connected to Relay NO
• N connected to Power Transformer 1 - Primary

HC-05 Bluetooth Module

• VCC connected to the 5V net
• GND connected to the common ground net
• TXD connected to Arduino Micro D0/RX
• RXD connected to Arduino Micro D1/TX

Documented Code

Arduino Micro (Rev3) - sketch.ino

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

}

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

}

Arduino Micro (Rev3) - documentation.txt

No additional documentation provided for the code.