Objective Development Forums

If you use avrdude, you should have drivers for USBasp installed. In this case I'd recommend USBaspLoader.

You probably don't link the assembler part. This routine is implemented in assembler.

The rate of calling usbPoll() is not too critical. The 50 ms are required during device enumeration. But once it is initialized, calling it every several 100 ms should suffice to avoid errors. It's not sufficient from a performance point of view, of course. If the device stalls at some point, I woul...

This is indeed not sufficiently documented. Since DDR and PORT = 0 is the default after a CPU reset, there is no need to initialize them in usbInit() or usbDeviceDisconnect(). If you have changed these defaults, you must set them back to 0 before calling any USB functions. I have updated the comment...

You can try the the very old version on the new chip first. If it does not fix anything, then it's probably not a firmware issue. Regarding pull-ups, zeners and LEDs: 1.5k is probably better, even if you run on 5 V. You need the additional current for the zeners. But if even 1k does not make a diffe...

Please have a look at the boot loaders at

http://www.obdev.at/vusb/prjprog.html

That's exactly what you want.

If the version of V-USB makes a difference, please try to find the last version which worked and the first which did not. Another comment makes me curious: You say that newer versions don''t fit in 4k: I've taken care that no new release exceeds the code size of the previous release. Are you sure yo...

This may also be a voltage level issue. Please check the idle voltage on D-, it should be close to 3.3 V.

The problem is not usbPoll(), it's the time spent in other interrupts or while interrupts are disabled. Other interrupts must have a sei as their first instruction (or at least within the fist 5 or 10 instructions) so that USB interrupts are not delayed for longer than a couple of microseconds.

The AVR is roughly 10 times too slow for this. USB hosts must implement Full Speed USB (12 MBit).

Your best option is probably to buy a cheap USB hub, crack the case and build it into your device.

The voltage levels should be OK. V-USB in conjunction with Arduino's runtime environment can be a bit problematic because Arduino was not made for real-time systems. The error message you see probably means that USB does not work at all. The first step of initialization, assigning an ID to the devic...

You need to change the pins for D+ and D-, possibly the interrupt and the boot loader condition. In the Makefile you need to change the fuse bits and the hexadecimal base address for the boot loader. That should be all.

mschoeldgen wrote:'Ow, btw is there a dedicated bug report form / forum ? Its no biggie but the Tiny's 25/45/85 really do not work with V-USB if using other ports than PB0 and PB2 , must be some minor thing.

There is NO such known bug. However, if you use an interrupt different from INT0, you need some extra config.

You don't need to re-initialize or re-enumerate. The driver handles this automatically. There are two ways to detect disconnect: (1) Add hardware to check for USB power, or (2) Check for USB frame pulses. For (2), see e.g. Henrik's USB2LPT: m Please note that the frame pulses will also go away when ...

If you can find the difference in the headers and why this causes a problem, please file a bug report for avr-libc!

But before you file a bug report, please make sure it's really a bug in the header, not a missing configuration on your side or something similar.