lm35 interfacing with 8051 using adc0808 in proteus

Hi Everybody! This project demonstrates the look, development and operation of the international scale measuring device victimization LM35 Temperature sensing element and AT89C51 Microcontroller.

lm35 interfacing with 8051 using adc0808 in proteus

[otw_is sidebar=otw-sidebar-1] The circuit contains the analog temperature sensing element LM35 that has the advantage of providing Associate in nursing output directly proportional to the stargazer Temperature, while not having the necessity to be label. The project additionally consists of the eight bit Analog to Digital convertor ADC0804 that uses the sequent approximation conversion technique. The ADC0804 is controlled by the microcontroller, which processes its output to show the resultant temperature reading on Associate in nursing display. This text provides details regarding the microcontroller program, circuit style and therefore the circuit operation.




The circuit works on the concept of Analog to Digital changes. The temperature is perceived by Associate in Nursing Associate in Nursing log temperature sensing element  and this analog worth is born again in to a digital worth victimization an ADC. A microcontroller then processes the digital signal to show the temperature reading in stargazer on the visual display unit.

Components Needed






Temperature Sensor


Circuit Design in Proteus

The generator circuit consists of a quartz oscillator with oscillation frequency of eleven.11.0592 MHz. The reset circuit is intended employing a switch, a one0K resistance and condenser of 10µF to make sure a reset pulse dimension of 100ms and a reset voltage of 1.2V. Semitic deity Pin is force high employing a 10K resistance. The LM35 3 pins: GND, VOUT and VS. VOUT of LM35 is connected to Pin VIN of the ADC0804 IC. Pin twenty of ADC0804 is connected to +5V offer. Pins 1, 2, 7, eight and ten atomic number 55, RD, VIN, GND of ADC0804 square measure connected to GND. A 10k resistance is connected between the clock pins CLKR and CLKIN Pins nineteen and four of ADC0804. The 8 knowledge out pins DB0 to DB7 of ADC0804 square measure connected to PORT2 Pins of the 8051 Microcontroller.

lm35 interfacing with 8051 using adc0808 in proteus


The close temperature is perceived by LM35 temperature sensing element that produces Associate in nursing output voltage that’s proportional to the temperature at a rate of 10mV per degree Centigrade. This analog voltage is fed to the Analog to Digital convertor, which Associate in nursing eight bit ADC is acting on the principle of sequent approximation conversion. The Analog to Digital convertor ADC0804 is designed to unceasingly browse the input Analog signals and additionally unceasingly produces the Digital Output at its Digital out Pins. So as to create the ADC0804 to unceasingly browse the Analog Input values, we want to tie the INTR pin and WR pin along. Also, to unceasingly create the digital knowledge accessible at the Digital Out pins of the ADC0804, CS’ and RD’ pins should be force low. The Analog to Digital convertor, unceasingly takes the analog signal from LM35 and converts it in to digital values. The digital output of the ADC0804 is within the kind of eight bit binary knowledge and these are unceasingly accessible. 8051 Microcontroller takes this digital knowledge and performs an easy mathematical calculation. This calculation can convert the received digital knowledge from the ADC0804 to Temperature in degree Centigrade. Now, the microcontroller can send this knowledge to the display it. Since the ADC is unceasingly reading the Analog knowledge from the LM35 Temperature sensing element and causing it to the Microcontroller through the Digital Pins, the temperature are going to be updated in any respect times and therefore the same is displayed on the digital display.

lm35 interfacing with 8051 using adc0808


  1. It may be used at mobile places like cars to stay a track of the temperature.
  2. It may be accustomed management the shift of hundreds like motors, heaters primarily based upon the temperature.
  3. It also can be used at homes to induce the temperature reading.



  1. It needs further analog to digital conversion.
  2. This circuit will solely live values in stargazer.


So this can be it. I hope you concentrate on this guide helpful. Let Pine Tree State apprehends if you needed any facilitate with its come. Can meets you guys next time. Until then lookout, have additional fun.