Objective Development Forums

Does VUSB have bidirectional implementations available (as in working in real life)?

I know the firmware supports bidirectional communication (or am I mistaken?), but I want to see a complete project that uses that.

Would it be a full duplex operation (maybe that would be taking it too far?)

I do have a question - if USBasp does not have bidirectional communication, how does it verify programming?

USB 2.0 spec itself doesnt support full duplex communication for that matter. No USB device ( yes , even a hi speed one ) as of today supports full duplex communication.

USB 3.0 i think will support full duplex communication at super speed ( 5 Gbps ) .Something impossible and unnecessary on an 8bit controller.

Ah .. so all USB communication is half duplex!

This means that if I were to create a TTL serial <-> USB convertor, for example, and had the serial port been full duplex, I would have to have large buffers on the serial port side to buffer in/out data until it got sent through the USB port?

1. Does that mean a TTL serial <-> USB convertor is never a true convertor? In other words a full duplex serial port after a TTL serial <-> USB conversion becomes a "virtual half duplex" serial port (if I wre to emulate a serial port on the USB side)?

2. What are good half duplex projects using VUSB?

thats right . you have to use large buffers for a serial COM - USB converter. Or you can reduce the speed of the serial COM to much less than half of the maximum data transfer speed USB offers and manage with a small bufer.

1. thats right.

2. There are so many fantastic projects made using V-USB here. http://www.obdev.at/products/vusb/projects.html .