Abstract

• The “Temperature Indicator Circuit” is mainly implemented by using Arduino Uno microcontroller board and LM35. The peripheral components are 16 x 2 LCD, HC05 Bluetooth module, android phone, RGB LED (common cathode type), buzzer, fan with motor and relay module. The output data is sent to LCD, an RGB LEDs and android phone from Bluetooth module. An LM35 temperature sensor is used for sensing environment temperature. Different temperature ranges will produce a different color on an RGB LED. The Arduino Uno microcontroller sends the calculated temperature to 16 x 2 LCD and RGB LED and the user by using appropriate commands of LM35 temperature sensor. The sketch for the microcontroller were written in the Arduino programming language, debugged, complied and burnt into the ATmega328P microcontroller using the Arduino integrated development environment (IDE).