interface Potentiometer to PC

[jess]

Hi,
i want to read potentiometer value(0.0 to 1.0) to PC through any port(serial.parallel or usb).
is it possible to read value without using any microcontroller.

if can,
can u guide me.

Regards,
Jess

 

[elrayes]

only using parallel port however you will need A/D chip to get voltage from the potentiometer and calculate the resistance, serial and USB you will need microcontroller with them.

 

[jess]

thanks for ur reply.
what's the ouptput of adc?
it's o or 1 !

can i read the variation of output between o and 1.

regards,
Jess

 

[elrayes]

ADC output a group of 0's and 1's, just a converter to convert analog voltage value to a binary number can be processed and understood by a computer or a digital system.
if you are using 8 bits ADC then you will read binary values from 00000000 (0 in decimal) to 11111111 (255 in decimal) , this binary number is equivalent to the input analog voltage value.

you are welcome anytime to ask

 

[jess]

Thanks for ur reply.
yes. i know.
but i want to know the potoentimeter output is 0V/5V.
or
output voltage is varring from 0V to 5V.

and if output voltage is 5V,
ADC output is 0000 0101 or 1111 1111?

Regards,
Jess

 

[elrayes]

when the output voltage is 5 volts the ADC will output 1111 1111.
according to the reference voltage you will connect to the ADC IC you will define something called "Step", "step" is the minimum voltage change can be detected by the ADC and will take equivalent binary value.
step size = ref. voltage/((2^output bits)-1)
example: if you have 5 v reference and ADC with 8 bits output then the step size will be = 5v/255 = 0.019 volt.
then every 0.019 volt a new binary value will appear on the ADC output.
good luck