Objective Development Forums

AVR-USB hangs when using usbSetInterrupt(0, 0)

2008-11-20T01:44:13+02:00

Okay, thanks =)

Statistics: Posted by Alloc — Thu Nov 20, 2008 1:44 am

AVR-USB hangs when using usbSetInterrupt(0, 0)

2008-11-19T22:29:28+02:00

OK, you're right. My comment about passing zero length messages is wrong, this is explicitly handled in the driver.

However, a zero sized message may not be handled correctly by the host. This is actually a bug in the RemoteSensor example. You should send at least one dummy byte.

Statistics: Posted by christian — Wed Nov 19, 2008 10:29 pm

AVR-USB hangs when using usbSetInterrupt(0, 0)

2008-11-19T22:15:06+02:00

Hi christian,

thanks for the reply. Thought I could use it with zero bytes since it's used that way in the RemoteSensor example.
So is there any way to set the usb-interrupt without any data? Or do I have to use a dummy byte?

Regards,
Chris

Statistics: Posted by Alloc — Wed Nov 19, 2008 10:15 pm

AVR-USB hangs when using usbSetInterrupt(0, 0)

2008-11-19T22:07:26+02:00

usbSetInterrupt() requires a pointer as the first argument and a byte count (greater than zero!) as the second. Anything else may result in corruption of the internal data structures.

Statistics: Posted by christian — Wed Nov 19, 2008 10:07 pm

AVR-USB hangs when using usbSetInterrupt(0, 0)

2008-11-15T04:18:02+02:00

Hi,

I wrote a little fw which indicates whether the host should read data by setting it's interrupt1-in-flag. When I call the usbSetInterrupt-method by eg

Code:

usbSetInterrupt(&LED_PORT, 1);

it works fine. If I (at the same codeline) call it by

Code:

usbSetInterrupt(0, 0);

libUsb also returns from

Code:

usb_interrupt_read(handle, USB.REQ_TYPE_DIR_DEVICE_TO_HOST | 1, buffer, buffer.length, 24*60*60*1000);

but the control transfer directly following it

Code:

usb_control_msg(handle, USB.REQ_TYPE_DIR_DEVICE_TO_HOST |  USB.REQ_TYPE_TYPE_VENDOR | USB.REQ_TYPE_RECIP_DEVICE, 1, 0, 0, buffer, buffer.length, 5000);

does endlessly return

Code:

error sending control message: Protocol error

and usb_interrupt_read doesn't block anymore.

AVR-source and accessing Java-source attached.

Regards,
Chris

/Edit:
To clarify two things ... When I use

Code:

usbSetInterrupt(0, 0);

while the device isn't opened the function getString in Main.java fails to get the requested information of AVR-USB.
AVR-USB hanging does not mean that the whole uC hangs ... It's just AVR-USB not responding to requests.

Statistics: Posted by Alloc — Sat Nov 15, 2008 4:18 am