Comments on: Re: USB to Parallel Port Problem

By: salathia

salathia — Mon, 17 Dec 2012 11:30:39 +0000

And compatibility mode is the mode of PPDD not USBDD…… Acc. to the protocol of compatibility mode you must use two pins of Control Register and two pins of Status Register and 8 pins of Data register so total will be 12 pins that is used in compatibility mode and you are trying to use USB port that has only 1 pin for transfer and 1 for receiver. And i do not knw why intelligent guys like you do this silly mistake to use USB port for parallel port device driver……

By: salathia

salathia — Mon, 17 Dec 2012 11:20:30 +0000

As you already told that you have a USB to parallel port cable / converter. But you have written the code for parallel port device driver in compatibility mode. In USB port there are four lines -
1. Receive Data Rx.
2. Transfer Data Tx.
3. Power line for device. Vcc
4. Ground Gnd.
Here you are using USB port that is directly attached with your motherboard with some address that is stored in the ROM. but the driver that you have developed is PPDD(Parallel Port Device Driver) that has diff address stored in ROM. If you want to use USB port then you must implement USB port device driver rather then PPDD…….

By: Anil Kumar

Anil Kumar — Sun, 16 Dec 2012 16:03:35 +0000

okay,

My question is, How to make interface b/w USB to Parallel Port??

By: salathia

salathia — Sun, 16 Dec 2012 12:24:58 +0000

You will get the solution by three things:-
First thing is that you have developed parallel port device driver in compatibility mode.
Second thing is that you have USB to parallel port convertor.
Third thing is that you are trying to access USB port through your parallel port device driver.