Objective Development Forums

You need an embedded USB host for that. For a pen drive, you need at least full speed USB. See section "Embedded USB Hosts" on http://www.obdev.at/products/avrusb/links.html.

The 16 MHz version meets the specs reliably when you use bulk endpoints, the 12 MHz version is very close to the limit. Since one 8 byte chunk is duplicated, it's almost certain that this is a retry from the host. In principle, it's possible to filter out retries by checking data toggling. But I'd r...

I don't think that your USB adapter or host driver is broken. You can easily check this by connecting other devices. As already mentioned, the most likely cause is a signal level problem. If you are using zener diodes, the must be low power types (<= 500 mW). Try removing the zener diodes and insert...

This probably means that Sharity was not fast enough sending an ACK so that the host did a USB retry after some time. What clock frequency do you use? Can you reproduce this? If yes, do you have a digital storage scope to analyze it? Would be really interesting to find out why this happens since bul...

Windows always tries to refer to the device by name. If it does not know the name of the device, it was not able to read the device descriptor. Since this is a very basic thing, we must assume that USB does not work at all on these PCs. The most likely cause for this type of failure is in the hardwa...

You can mail patches to Thomas Fischl. If he does not respond, please consider adding something to our Wiki at http://avrusb.wikidot.com/, then post a link here in the forum.

AVR-USB needs the CPU as long as there is USB traffic. This is > 90% os the time if bulk endpoints are involved (as with CDC mode). For all other modes based on control transfers, it depends on how fast you respond to requests. As long as the host polls for a response, there's a lot of USB traffic.

You can do this with signals up to ~ 3 kHz. This gives an interrupt rate of ~ 300 microseconds which should be compatible with AVR-USB. For higher frequencies, you need a prescaler or simply count input pulses during a given period of time.

See the end of http://avrusb.wikidot.com/examples, the section about suspend mode. This explains how suspend mode can be implemented.

This must be a problem with libusb-win32. Please remove everything related to this lib and install it from scratch. Maybe a web search brings up something relevant.

I must admit that I don't know what Labview is. CDC mode uses ~ 90% or more of the CPU's time. If you just want to generate a PWM signal, that can be done in hardware with timer1, the hardware should therefore be good enough. AVR-USB can implement all types of interfaces. I don't know D2XX, but I'm ...

Regarding the previous question: You need the parallel port programmer only ONE TIME, when you program the AVR for your USB based programmer. Once that is done, you use USBasp on the USB port and no parallel port is needed any more. Regarding application development please see various examples on th...

Please get in contact with me at the support address. We can sponsor an ID for the MIDI device class.

Yes, that should be the procedure. You can also use avrdude for parallel port programming, not only for USBasp.

Yes, this is possible. You need to modify the interrupt configuration at the end of usbconfig.h. And you MUST make sure that no higher level interrupt is used (except if you know exactly what you are doing).