Here is a Simple Temperature Display Circuit using LCD (Liquid Crystal Display). For Heat Sensor we have used IC LM35 (Precision Centigrade Temperature Sensors) whose Output voltage is linearly proportional to the Celsius (Centigrade) temperature.
To achieve higher performance, (Engineering Level Project) you have to use Microprocessor, which is commonly used now day’s in most electronics gadget. i.e remote control circuit,UPS, TV circuit, Mobile, etc.
Advance Project requires a versatile circuit, same can be programmed for different work and can be capable of sensing from surroundings and giving output by using all types of sensors or module available in the market for eg. Remote Sensor, Keyboard, LCD Panel, Ultra sound sensor, RF Data, Sound, Gas Sensor, Memory chip reader/writer, heat sensor, humidity sensor, pressure sensor etc.
Learn to Programme ESP8266 Wi Fi Module using Arduino Software : Important Circuit for IOT Beginners.