JSS ACADEMY OF TECHNICAL EDUCATION,

BANGALORE
DEPARTMENT OF COMPUTER SCIENCE AND
ENGINEERING

MINI PROJECT REPORT ON

DISPLAY TEMPERATURE ON 7 SEGMENT DISPLAY USING
LM35 SENSOR

Submitted by:
Name: [Your Name Here]
USN: [Your USN Here]

Under the guidance of:

Mrs. Bhavani B H
Faculty, Department of CSE

Department of Computer Science & Engineering

JSS Academy of Technical Education, Bangalore
Table of Contents
1. 1. Abstract
2. This project focuses on the development of a simple, cost-effective embedded system
that accurately monitors ambient temperature using the LM35 temperature sensor and
displays the real-time value on a 7-segment display. The LM35 sensor outputs an
analog voltage proportional to the surrounding temperature, which is read by a
microcontroller such as an Arduino or ATmega using its ADC (Analog-to-Digital
Converter). This digital value is then processed to calculate temperature in degrees
Celsius and is visually presented using a 7-segment numeric display, enabling clear
and immediate feedback.

The primary goal of this system is to demonstrate foundational embedded interfacing

techniques, including sensor integration, ADC conversion, and numeric output
formatting. Its applications are widespread — from basic room temperature
monitoring to usage in HVAC systems, laboratories, and home automation setups. In
addition to its practicality, this project serves as an excellent learning model for
students and enthusiasts new to embedded systems.

Key advantages of the project include its simplicity, low power consumption, real-
time monitoring capabilities, and ease of implementation. The system also offers
room for future enhancements such as wireless temperature transmission, conversion
to dual-scale display (°C and °F), or integration with IoT platforms for cloud-based
monitoring. By successfully implementing this project, learners gain valuable hands-
on experience with electronic components and microcontroller programming,
reinforcing their understanding of sensor-based automation systems.
3. 3. Objectives
4. The primary objective of this mini project is to design and implement a real-time
temperature monitoring system that utilizes the LM35 temperature sensor to read
temperature values and display them on a 7-segment display. The project aims to
provide a clear understanding of sensor interfacing and analog-to-digital signal
processing using microcontrollers. The key objectives include:

- To monitor ambient temperature accurately using the LM35 temperature sensor.

- To utilize a microcontroller’s ADC feature for converting analog sensor data to
digital format.
- To format and display the temperature reading in Celsius on a 7-segment display.
- To strengthen embedded system programming skills through real-world hardware
interfacing.
 - To lay a foundation for enhancements like wireless transmission, data logging, and
cloud integration.
5. 5. Block Diagram
6. 6. Components Required
7. 7. Working Principle
8. 8. Circuit Diagram
9. 9. Program/Code
10. 10. Flowchart
11. 11. Advantages
12. 12. Applications
13. 13. Result and Output
14. 14. Future Enhancements
15. 15. Conclusion
16. 16. References
17. Appendix
1. Abstract
This project focuses on the development of a simple, cost-effective embedded system that
accurately monitors ambient temperature using the LM35 temperature sensor and
displays the real-time value on a 7-segment display. The LM35 sensor outputs an analog
voltage proportional to the surrounding temperature, which is read by a microcontroller
such as an Arduino or ATmega using its ADC (Analog-to-Digital Converter). This digital
value is then processed to calculate temperature in degrees Celsius and is visually
presented using a 7-segment numeric display, enabling clear and immediate feedback.

The primary goal of this system is to demonstrate foundational embedded interfacing

techniques, including sensor integration, ADC conversion, and numeric output
formatting. Its applications are widespread — from basic room temperature monitoring to
usage in HVAC systems, laboratories, and home automation setups. In addition to its
practicality, this project serves as an excellent learning model for students and enthusiasts
new to embedded systems.

Key advantages of the project include its simplicity, low power consumption, real-time
monitoring capabilities, and ease of implementation. The system also offers room for
future enhancements such as wireless temperature transmission, conversion to dual-scale
display (°C and °F), or integration with IoT platforms for cloud-based monitoring. By
successfully implementing this project, learners gain valuable hands-on experience with
electronic components and microcontroller programming, reinforcing their understanding
of sensor-based automation systems.

2. Introduction
Temperature monitoring is a fundamental requirement across a wide range of
applications such as environmental sensing, industrial control, home automation, and
electronic appliances. Accurate temperature sensing ensures efficient operation, safety,
and energy management. This mini project is designed to implement a basic temperature
measurement system using the LM35 temperature sensor, which outputs a voltage
directly proportional to the temperature in degrees Celsius. The analog output of the
LM35 is fed into a microcontroller equipped with an Analog-to-Digital Converter (ADC).
The microcontroller processes the digitized signal, calculates the temperature, and
outputs the result to a 7-segment display. This provides a real-time numeric
representation of the temperature that is easy to read and understand.

The LM35 sensor is ideal for such projects because of its high accuracy, linear output (10
mV/°C), and ease of integration. The use of a 7-segment display enhances user
interaction by providing a clear digital output without needing a more complex interface
like an LCD. This project not only demonstrates fundamental embedded system skills,
such as sensor interfacing, analog-to-digital conversion, and output control, but also
teaches how to integrate software and hardware for real-world applications. Additionally,
it acts as a foundational model that can be further developed into more sophisticated
systems involving wireless data transmission, data logging, or smart automation features.

3. Objectives
The primary objective of this mini project is to design and implement a real-time
temperature monitoring system that utilizes the LM35 temperature sensor to read
temperature values and display them on a 7-segment display. The project aims to provide
a clear understanding of sensor interfacing and analog-to-digital signal processing using
microcontrollers. The key objectives include:

- To monitor ambient temperature accurately using the LM35 temperature sensor.

- To utilize a microcontroller’s ADC feature for converting analog sensor data to digital
format.
- To format and display the temperature reading in Celsius on a 7-segment display.
- To strengthen embedded system programming skills through real-world hardware
interfacing.
- To lay a foundation for enhancements like wireless transmission, data logging, and
cloud integration.

4. Literature Survey
Numerous temperature monitoring systems have been developed in both academic and
industrial contexts using sensors such as LM35, DHT11, and DS18B20. Among these,
the LM35 stands out due to its ease of use, linear analog output (10 mV/°C), and
reliability over a wide range of temperatures. Its internal calibration reduces the need for
external calibration, making it suitable for low-power and cost-sensitive applications.

Previous studies and implementations have shown that microcontrollers such as Arduino
Uno, ATmega328, or PIC microcontrollers are capable of efficiently interfacing with the
LM35 sensor. The processed digital data from the sensor is often displayed on LCDs,
OLEDs, or 7-segment displays. In this project, a 7-segment display is chosen due to its
simplicity and low component cost.

The project aligns with fundamental principles of embedded systems—demonstrating

how sensor data acquisition, ADC conversion, and output formatting can work in tandem
to create a fully functional temperature display device. It serves as a starting point for
more complex systems such as smart thermometers, climate monitoring devices, or IoT-
connected environmental trackers.
5. Block Diagram
The block diagram of the system consists of the LM35 sensor, an ADC (if required),
microcontroller (Arduino/ATmega), and a 7-segment display.

6. Components Required
- LM35 Temperature Sensor
- 7 Segment Display
- Arduino/ATmega Microcontroller
- Resistors and Connecting Wires
- Breadboard
- Power Supply

7. Working Principle
The LM35 outputs an analog voltage proportional to the temperature (10 mV/°C). This
voltage is read by the microcontroller’s ADC pin, processed, and the temperature value is
converted into a format suitable for 7-segment display.

8. Circuit Diagram
[Include diagram here]

9. Program/Code
// Sample Arduino Code:
void setup() {
Serial.begin(9600);
}
void loop() {
int value = analogRead(A0);
float tempC = value * 0.48828125;
Serial.println(tempC);
delay(1000);
}

10. Flowchart
[Insert flowchart of process: Start → Read sensor → Convert data → Display → Repeat]

11. Advantages
- Simple and cost-effective
- Easy to implement
- Low power consumption
- Real-time monitoring
12. Applications
- Home and industrial temperature monitoring
- Air conditioning systems
- Lab temperature logging

13. Result and Output

The system successfully displays the real-time temperature on a 7-segment display with
minimal delay and good accuracy.

14. Future Enhancements

- Use of wireless communication to display remotely
- Display temperature in both °C and °F
- Logging temperature to cloud or SD card

15. Conclusion
The project effectively demonstrates temperature measurement and display using
embedded systems, fulfilling the core learning objectives.

16. References
- www.arduino.cc
- www.engineersgarage.com
- Datasheet of LM35
- Embedded Systems by Raj Kamal

Appendix A: Additional Information

This section contains supplementary information, including test cases, extended data
results, component datasheets, or detailed logs from hardware execution.

Appendix B: Additional Information

This section contains supplementary information, including test cases, extended data
results, component datasheets, or detailed logs from hardware execution.

Appendix C: Additional Information

This section contains supplementary information, including test cases, extended data
results, component datasheets, or detailed logs from hardware execution.

Appendix D: Additional Information

This section contains supplementary information, including test cases, extended data
results, component datasheets, or detailed logs from hardware execution.