temperature sensor using 0808 adc

[abhimohit]

hi yr ,
actually i m measuring temperature using lm35 and adc 0808
now the problem is i made connection according to mazidi (book of 8051 controller)
and program which is given in same book also ...but i can't find the result .in fact i didnot find the any output on the lcd means it did not show any output ..
plzzzzzzz help meee....is there any way out

 

[cameo_2007]

you have to divide this into different sections in order to identify the problem.

Basically, it can be split into

1. Hardware
2. Software

and further H/W can be split into

1. LM35
2. ADC
3. Microcontroller

As a first step, take the Hardware section.
1. LM35
Observe the output pin of LM35 with a voltmeter or oscilloscope.
you have to verify that, whether the output changes with respect to the temperature.This can be done by placing the soldering iron tip near the sensor, to vary the temperature. For LM35, i think for every 1degree rise, the out put voltage should be increased with 10mV. If you can observe this, this part is fine and proceed to the next.

2. ADC0808
Observe the digital outputs with and vary the temperature as done in the previous step.If the digital output varies accordingly, you have no problem here.

3. Microcontroller.
Verify the wiring and circuit set up whether you have done it correctly.

Software

If you couldnt find any problem with the hardware, then obviously the problem lies in the software.Though the codes are taken from the book, there can be something which you have to set/reset yourself, which may not be mentioned in the book.For that you need to get the program here, so that someone can have a look at it.

 

[abhimohit]

thanks for your mail.. and how can i check the digital output of the adc0808.
either that output is correct or not and the last thing is lm 35 heats up very fast ...
is heating means the damage of ic or its heats normally when its work ..

 

[qwertyuiop415263]

you should first simulate your project on the simulation software like proteus or multisim, then your should come to real hardware part.

 

[cameo_2007]

thanks for your mail.. and how can i check the digital output of the adc0808.
either that output is correct or not and the last thing is lm 35 heats up very fast ...
is heating means the damage of ic or its heats normally when its work ..

to check the digital output you need to know what is the resolution of the ADC.ie what is the analog voltage at the i/p for every 1 bit change.

NO. LM35 will not get heated while working, by itself. There must be something wrong.Either wrong connection or damaged component

 

[khyati katakia]

can i have the circuit diagram in proteus for the temperature sensor using lm35 and 0808adc

 

[twim]

visit this web **broken link removed**