Parallel Port Power

P

prabhatdreamz

Disciple
I am doing my engineering final year project, and as a part of that project, I am required to get a digital data from a single channel, 8 bit, and 200 Msps ADC (ADC08200) and transfer it thru the parallel cable to the parallel port of my PC, where the digital data arriving on the individual data pins on the port will be accessed by a C code. According the manual provided by the ADC manufacturer, we have prepared the circuit on a PCB. The power requirements for the ADC is about 3V too much above that , it might damage its components (as told to me by the guy who did all the PCB stuff, ELECTRONICS GUY, me - COMPUTER GUY :p ) he said that the digital data won't be recognized by the PC parallel port, since in order to get logic "1" 5V is required, but thru the PCB I am only able to get 3V or probably less than that. Bottom line is I won't be able to access the data thru my code from the port due to power shortage, Is this really the case. Will really not be able to read any relevant data as there is no 5V power for the parallel port? Plz someone reply soon, i am already thru my deadline , desperately need guidance.
 
Thanx a ton for the prompt reply, btw just a little update(since today itself I kinda understood the whole thing my ELECTRONIX guy was trying to tell me :p ). Well the thing is that PCB which provides 3V and the port socket for plugging in the parallel cable, till that instance, all the high and low values seem to be arriving w/o ne glitch (the guy tested it), the problem he says is when I channel that digital o/p from the socket thru the cable to the PC's parallel port, coz he says that he has read somewhere that in order for the PC to recognize the data arriving at the parallel port, 5V is necessary for "1" else it might not recognize, and therefore my C program won't be able to retrieve the value. Is this really the case, does PC really operate that way in order to interface with the data on the parallel port. Sorry for the pain, but plz need prompt reply to this too.
 
You can use a optocoupler to connect the parallel port to the PCB. Optocoupler is basically a chip that isolates your PC from PCB, and accepts only the signals from PC. Its o/p is driven by a separate power source. Its safe for you PC also :hap2:
 
Back
Top