This project is standalone digital temperature indicator which can also control the temperature of the heating element of a device according to its requirement. Use of embedded technology makes this closed loop feedback control system efficient and reliable. Microcontroller (ATMega 328) allows dynamic and faster control. Push button switches and liquid crystal display (LCD) make the system user-friendly. The sensed and set temperature values are simultaneously displayed on the 16×2 LCD Display panel. The circuit is programmed for on/ off control.
ARDUINO is the heart of the circuit as it controls all the functions. The temperature sensor LM35 senses the temperature and converts it into an electrical signal, which is applied to the micro controller through ADC. The analog signal is converted into digital format by the analog-to-digital converter (ADC). The sensed and set values of the temperature are displayed on the 16×2-line LCD. The micro controller drives a transistor to control the heating element with the help of an electromagnetic relay. The set temperature value can be varied from 1C to 150 ‘C temperature. The dc relay is connected to the micro controller through a driver transistor. The relay is used to operate the fan / coolant or to operate any other electrical device. Normally the relay remains off. As soon as pin of the micro controller goes high, the relay operates. Thus , we can set any required temperature using switches anytime and fan gets controlled automatically based on it.
It is very compact using few components and can be implemented for several applications including air-conditioners, water-heaters, snow-melters, ovens, heat-exchangers, mixers, furnaces, incubators, thermal baths etc. This project is useful in process industries for maintenance and controlling of Boilers temperature.
Software Tools:
- ARDUINO IDE
- EMBDDED CPP CODE
- PROTEUS SIMULATOR
Hardware :
- ATMEGA328 Microcontroller
- LM35 Temperature Sensor
- Transistor Driver BC547
- Switches
- Relay
- 16*2 LCD DISPLAY
- DC Fan
- Regulated Power Supply