Thermometer with 7 segment

Hi.. i'm new comer here...
Can u help me...
I need to build thermometer with AT89C2051 with seven segment display and can meansure above 100 Celcius. Have anybody done with project like this?
I need the source code...With circuit is better...:D

first u choose that which temperature sensor and ADC you are going to use.since u r going for 7 segment display and AT89c2051 so if u use ADC0804 or other like this and LM35 then there will be problem because no of i/o ports in AT89c2051 are less than AT89c51.other option is DS1620 or other like this ,and if u choose it, u dont need to use any ADC and i/o ports will be in your range.so make some better choice first

zerisha ,
since u have decided to use 89c2051,seven segment display,
u dont have much option but to use an I2C/SPI ADC .
visit the nxp application notes section , there u can find application notes/datasheets as well as code examples.
before all that, have u selected ur sensor?

there are temperature sensors that give digital data directly that u can read using I2C protocol,
but that can prove to be a little expensive.

well.. I think you already got choices.. i also recommend you to use I2C.

But its not that with AT89C2051 you cannot use 7-segment and ADC.

Here is a solution.. use an 8-bit SIPO latch shift register and you only need 3 pins to interface your 7-segment which you can do with P3 of AT89C2051, ADC data pins can be connected to P1 and control pins of ADC can be connected to the rest of P3 pins.
and you will still have 1 extra pin left that you can use for anything else... like a buzzer or LED.

Economical and fast!!

I have got circuit for my requirement, but using AT90S2313 with DS1820.
I heard AT90S2313 was obsolete. Can i replace it wit ATtinyi2313 without change the source code?

Just take care of pinouts and see if any change is necessary.. most probably there wont be any.. coz AVRs are almost same and ATtiny and ATmega are derived from AT90S.
If you feel any problem.. see the migration note if available for migrating from AT90S2313 to ATtiny2313. you can get it from atmel's website.