Objective Development Forums

Hi -

The project I'm working on needs both interrupt-in and interrupt-out transfers at the same time, and I'm using libusb 1.0 at the host end, latest vusb at the driver end.

I've got control transfers working ok, and interrupt-in, but now I'm trying to get the host to send interrupt-out packets to the device, it doesn't work.

I've done the following:

USB_CFG_HAVE_INTRIN_ENDPOINT3 = 0
USB_CFG_IMPLEMENT_FN_WRITEOUT = 1
I've implemented a usbFunctionWriteOut() method

At the libusb end:



When I send a couple of characters to the endpoint I get error -5 which is LIBUSB_ERROR_NOT_FOUND

I suspect that the issue is that the endpoint doesn't exist or I'm addressing it wrong. Can anyone help me with what I'm doing wrong - have I missunderstood how to address the interrupt-out endpoint?

Another related question - is an interrupt-in and an interrupt-out endpoint two endpoints or one? The host software reports that configuration as having 1 endpoint (apart from control) so does this mean I'm missing an endpoint?

I've looked for example of interrupt-out endpoints and cannot find any.

Thanks!

Daniel

Sorry for replying to my own post, but I've managed to get it working (or at least, got past the current issue). What I didn't realise was that to use interrupt-out endpoints you need to create a custom config descriptor to describe the out endpoint. Once I did this its working a lot better.

Daniel

Yes. For every non-trivial configuration, you need to create your own descriptor. And in order to use more than just control transfers on endpoint 0, you must set a configuration and interface with libusb.