Objective Development Forums

Maybe I'm mistaken but I'm not seeing the pull up resistor to D-? It's R3 in this schematic: http://www.obdev.at/Images/vusb/circuit-zoomed.gif
It's very important for it identifies the device as a low speed device.

For documentation not to get lost, you might want to put it on the wiki? http://vusb.wikidot.com/

The schema looks fine.

Few things to check:
Make sure you really have 3.6v zener diodes.
Make sure your crystal matches your compiler settings.
Make sure your fuse settings have the external crystal configured.

I'm very sure I've used my V-USB project with Ubuntu Linux 10.10 with proper Vendor and Product stings. But I haven't checked lsusb. I was using libusb to talk to my device as done in a few examples.

I recommend against using the CDC drivers. As the drivers are hard to install, it violates the spec, and doesn't work with all USB chips.

It's much easier to use the HID mode as supported by AVRDude.

Also, GPL infects. Any source coming on contact with GPL code also needs to be GPL. So if you use an LCD library with V-USB for example, then you also need to put that under GPL. Just that part is unclear to me. I understand that all stuff in AVR (Firmware) must be released as source. But I'm not s...

I'm not a lawyer, so if you want to be 100% sure then consult one. But GPL is not that hard to read, just try to read if. It's quite simple, with the binary (in any form, so also as firmware in a device) you need to give the source-code, or a way to give the source code. A simple text file say "...

The license doesn't cover the PC side. The license also doesn't cover the schematics as far as I know. It only covers the microcontroller code. Just publish the source and have no fear. Many projects sell open source products, arduino being one of the major visible projects. And with only 8-10 custo...

There are quite a few examples of reading/writing data to USB-HID devices. To name an example, BootloadHID: http://www.obdev.at/products/vusb/bootloadhid.html

Because bulk endpoints are not supported by the low-speed spec officially. Some versions of Linux try to map bulk endpoints to interrupt endpoints on low speed devices and this mapping is broken. You need a kernel patch (included in the newest vanilla kernels >=2.6.23) on these kernels. Windows Vist...

Make sure you have F_CPU defined as 12000000 because of your 12Mhz crystal. In the main loop, only call usbPoll(); for now, until it works. Use a known working descriptor. I always use the hid-mouse example to test new v-usb hardware. Make sure your pin configuration matches (usbconfig.h), because t...

Both. The USB pins are bi-directional. I think the USB code configures them anyhow, for bi-directional ports you need to change both the DDR and PORT register.

If it's just one machine it's most likely an electrical problem. Some machines are way more picky on the USB communication lines then others. Try a different USB cable, re-solder all your connections (I had one bad connection once, caused problems on only a single machine). Make sure you have a 100n...

Those fuse settings select a low frequency crystal, you want a high frequency crystal selection. It's also better to turn on the brownout detector. I've used low: 0x3F high: 0xC9 with succes on the ATMega8A. You can check the fuse settings here: m I'm not sure if MacOS has the command "lsusb&qu...