PL2303 USB to RS232 driver source code?

I'm looking for the source code for the PL2303 USB to RS232 adapter cable. I hope to make it somewhat more functional.

I have had good luck with the device. The driver seems to sense hardware signal changes (DCE ready, DCD, CTS). At 110 baud, the meter needle swings when connected to the Tx pin, and I type a character at the keyboard. But there is no echo when I connect Rx to Tx. (This is under Win XP SP3).

The driver version that works is V2.0.0.26, dated 25/06/2004, and has the name "USB to Serial Comm Port" an earlier version (V2.0.0.25) named "USB to Serial Port Bridge" also seems to work. Later drivers (2009, 2010) don't work with this cable. I did not purchase this cable directly from Prolific.

I have had similar results with these drivers under Vista Home Premium.

source code for a commercial device , may not be availbale IMO.

but for the gpio part of the pl2303 one may have a chance to get.

Re: PL2303 USB to RS232 driver source code or API documentation?

srizbf said:

source code for a commercial device , may not be availbale IMO.

but for the gpio part of the pl2303 one may have a chance to get.

Click to expand...

I suppose that's true, but no one seems to know the makers of these adapters and yet drivers are everywhere. Even Prolific claims not to make the adapters but offers a driver for free.

I don't know what exactly GPIO means in this context. If you are referring to the API to talk to the PL2303, then I would expect Prolific to provide the documentation for it. But someone must have thought of this before.

I assume the driver for the adapter provides a virtual COM port to Windows. I also assume that the chip sends messages to the USB side of the driver to pass data and control signal status and commands (DCD, DTR, RTS, CTS, etc.).

prolific make pl2303 chips.
others make use of it to build adapter.
prolific gives reference design and drivers.

GPIO-General Purpose IO

srizbf said:

prolific make pl2303 chips.
others make use of it to build adapter.
prolific gives reference design and drivers.

GPIO-General Purpose IO

Click to expand...

Thank you; I know this. Without the source code and/or the SDK, its impossible to determine how to communicate with the chip.