Objective Development Forums

the HID descriptor is stored in flash by default:

PROGMEM puts it in flash.

V-USB in normal config doesn't use a lot of RAM. You can save 1 or 2 bytes by using the GPIOR registers as SRAM. But that's about it.

Because entering an interrupt routine disables global interrupts, and exiting the interrupt routine enables them again.

I've used timer interrupts to control step motors without an issue for the V-USB connection. Without enabling interrupts in the timer.

If you want to enable interrupts inside the interrupt you need to do an "sei();" call inside the interrupt.

This has nothing to do with V-USB.

But, FYI, most devices charge with just the power connected. However, the iPhone is different. It will not work with just 5V connected, search online and you'll find a solution.

This is possible, however, you need to make sure the USB interrupt is the highest you use. And you need to make sure your other interrupt doesn't take too long (or enable interrupts inside the interrupt routine)

I managed to reflash the bootloader using UsbTinyIsp and the config below, but now the Metaboard shows up as an "Unknown Device" and will not accept the drivers. An unknown device even shows up when there is no software in the chip, just the pullup on the D- line causes your machine to se...

It looks to me like only the lowest level bit-banging routines would need examination for use with the AVR32 instruction set, since the rest of the code is in C. I don't want to re-invent the wheel here, so please let me know if anyone has already tried this. Thanks, Most of the magic is in the low...

If the chip is lacking a bootloader then you need an "In Circuit Programer" (ISP) to program the chip. This is an additional piece of hardware. There are many different versions from cheap to expensive. However, I don't think people would sell this without the bootloader programmed. So it ...

My answer is as good as your question. You didn't give much info, so I couldn't give much info.

Any chance the PC goes into some hibernation or powersaving mode? USB supports that but V-USB doesn't.

Yes.

I've used almost the same descriptor for a gamepad without problems for WinXP and WinVista.
But maybe the PID/VID pair has something to do with it. Or the silly caching that windows does.

Well, USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH should not be larger then 255 I can say you that with a quick glance at the code. But I don't think you have crossed that limit. Other then that I don't know...

Using V-USB as serial driver will is problematic. Because the CDC profile is not allowed with low-speed (and V-USB is always low-speed). It is possible, but it requires some hacks on the computer side. Also new USB chips seem to refuse this in some cases, and Windows 7 has also made this harder. In ...

You cannot "break" an AVR with wrong fuses. The only 2 things you can do that cause problems:
-Disable ISP (however, this is only available when using high voltage programming)
-Set an external crystal without having one connected