Displaying the output of LM35 on PC using parallel port interface

[enigmatic_nexus]

Hello Every1
I have been assigned with a semester project which involves displying the output of LM35 on PC using parallel port interfacing and turbo-C/VC++..Please guide me on how should I achieve it, especially the circuit for the 8-bit ADC being used. I have spent a lot of time on the internet but still have doubts on how the circuit for ADC should actually be.. THanks in advance

 

[_pv]

Using LPT port, or even RS232 (there are number status and control lines that could be used as GPIO), you could make SPI interface, by switching and reading pins in correct order. The only thing is to translate the logic levels. LPT - 0V..+5V, RS232 -12V..+12V.
Then any ADC with SPI interface would fit.
But there is an easier way to take temperature sensor with builtin ADC and SPI interface, like LM74 (it has +5V power supply) and connect it to PC.

 

[enigmatic_nexus]

Thanks for the great idea But i want to interface the temperature sensor output with PARALLEL PORT and not SERIAL PORT. LM74 is SPI (Serial peripheral interface) . Can you tell me if there is any temperature sensor that functions the same way as LM74 but can be interfaced with PARALLEL PORT???

 

[_pv]

Thanks for the great idea But i want to interface the temperature sensor output with PARALLEL PORT and not SERIAL PORT. LM74 is SPI (Serial peripheral interface).

It does not matter parallel or serial port (i mean not to use UART tx and rx pins but status and command lines), both could be used just as GPIO(general purpouse input/output).
You could set some output pins to 0 or 1 and read status of input pins, and doing so in correct order implement SPI or I2C or any other serial interface with LPT.
have a look on schematics of different programmer cables: ponyprog, avreal, altera byteblaster.

 

[Jack// ani]

Well you can use good old 8-bit ADC0808, see this **broken link removed**

8-bit data readout can be done by through data port, and control signal to ADC can be give by control port. Use SPI will reduce wire count significantly, but programing part will be bit involved.

Hope this helps