89c51 based temperature measurement with ds18b20
A DS18b20 sensor is used for measurement here with 89c51 ic of 8051 family, for temperature measurement and presented on serial terminal.
ds18b20 is capable of measuring temperature in the range of -55 °C to 125 °C with 0.5 °C accuracy. For the purpose of transferring data to the microcontroller, a special type of serial communication called 1-wire is used as the communication protocol.
Introduction for the project
The hardware setup is fairly straightforward when using several 1-Wire temperature sensors, such as the DS1820, as shown in the block diagram below.
The temperature sensor and the microprocessor communicate using a single-wire bus. Through this 1-Wire bus, it is also possible to directly power the gadgets.
Because each 1-WireTM device has a distinct 64-bit ROM code identifier that is used to address each sensor, a virtually infinite number of 1-WireTM devices can be attached to the bus.
+5v power is given to the pin no. 40 of the ic and specially to the pin no. 31 of the ic to read the code from internal memory of the controller.
pin 20 of the ic can be grounded for the proper working of the circuit.
The oscillator circuit made with ic 89c51 uses the crystal of 11.0592 mhz which is suitable for the serial port operations.
The circuit drawing is shown of the "proteus simulation and you can download all files ( simulation + Keil Microvision project files ) Here.
One extra card module is shown in the above picture is useful when your computer does not have the serial port, and you want to use the USB port as the serial port same as the serial port communications.
The part List for the project
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IC 7805
ic 89c51
ds18b20
crystal - 11.0592 Mhz
disc capacitors -- 33pf each
led - red
resistor 180 ohm
40 pin ic soket
general purpose PCB ( let us know if you want us to design the PCB of this project)
wires, solder iron, solder wire,
and some more simple things....
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