Room temperature monitoring project – working principle
Lm35 temperature sensor analog room temperature measuring – Analog to digital converting principle
If you are new and don’t know much about working and pin out of LM35 temperature sensor. Than please take the below tutorial. Its an introduction to LM35 temperature sensor, its pin out and working principal. The tutorial will help you in understanding the code below.
Digital Thermometer with 8051 microcontroller – Project requirements
- 89c51 or 89c52 microcontroller (You can also use any other)
- ADC0804 (Analog to digital converter)
- LM35 temperature sensor
- 16×2 lcd
- power supply(5 volts)
- Bread board (to make circuit)
- Crystal (11.0592 MHz)
If you are new and didn’t know about ADC0804 and 16×2 lcd. Below are some good tutorials.
8051 digital temperature monitor – Circuit connections
LM35 temperature sensor has three legs one for input voltage (5v), one is GND (ground) and the third is output voltage or temperature in Celsius. LM35 gives 1 degree Celsius change in temperature on every 10 mv rise in temperature. Vref/2 pin is very important pin. It is used to set reference voltage for ADC0804. Apply 1.28 volts to this pin. This will make the ADC0804 to increment the value on every 10 mv rise in temperature. Now both ADC0804 and LM35 have same voltage configurations.
Ground lcd ground pin. Apply 5 volts to vcc pin of lcd. Set contrast on contrast pin of lcd use potentiometer/variable resistor for setting contrast. The CLK R and CLK IN pins of ADC0804 are clock pins you connect an external clock with these pins.But the better way is to use the configuration given below 10 k resistor in parallel with 150 pf capacitor it will utilize your internal clock. If you want to use external connect and external clock to CLK IN pin and leave CLK R void.
89c51 digital thermometer – Project code
Filed Under: 8051 Microcontroller, Microcontroller Projects