The LM35 of National Semiconductors that is used in this project is a precision centigrade temperature sensor, which has an analog output voltage. It has a range of -55ºC to +150ºC and a accuracy of ±0.5ºC . The output voltage is 10mV/ºC . The output voltage is converted by the AD convertor of the AT Mega8. The temperature is displayed on an LCD module. In this example the thermometer has a range of 0ºC to 40ºC and a resolution of 0.5ºC. If you want to have a read out in Fahrenheit you can use the LM34.
This is a design for digital thermometer that can display using LCD. This is the figure of the circuit.
In the circuit the LM35 is connected to the ADC port of the ATMega8. The ATMega8 uses a crystal as an oscillator for the clock pulses. At PORTD of the ATM8 an 20x4 LCD display is hooked to display the temperature in a discrete value and in a analog bar.
