Objective Development Forums

Hm, ok ^^
Still if there's any need for any tests or such I would gladly help out ... You're really doing a wonderful job here for many AVR-users =)

Regards,
Chris

Hi, I really like AVR-USB very much and appreciate the work put into it. So I'd like to ask if there's any way to help you (the developers) (not by writing USB code, but anything else) or at least give you a few bucks for your work. I know of the hobby-license but as I see it that's not only giving ...

Since there are no subroutine calls in the vector (or did you talk about sub-calls in the whole source?) that's probly not possible. Does avr-gcc use any registers as special functions? Eg, why does avr-gcc push all those registers at the beginning of the interrupt? 282: 1f 92 push r1 284: 0f 92 pus...

I use the 16 MHz variant ... unfortunately there's no information on "allowable interrupt latency". Only 12 and 16.5 MHz include that information.

For USART_UDRE, you probably need to write an assembler routine. Executing sei() after resetting the pending flag might be too slow. But look at the disassembler listing to be sure. At how many cycles starts "too slow"? 00000282 <__vector_14>: 282: 1f 92 push r1 284: 0f 92 push r0 286: 0f...

Hi, think I understood the reason ... The UDRE-flag is set as long as UDR is not written to. By enabling interrupts at the beginning of the UDRE-interrupt another interrupt is executed ... endless loop. Is the USART_UDRE_vect0-ISR small enough for not enabling interrupts? Btw, you (christian) sugges...

Hi, I'm currently trying to get a mega16 to act as a bridge between USB and USART. Everything works fine, as long as I don't enable the USART Data Register Empty Interrupt (USART_UDRE_vect). As soon as I enable it the uC hangs and after a short period does a watchdog-reset, *but only* if the interru...

Okay, thanks =)

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

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 usbSetInterrupt(&LED_PORT, 1); it works fine. If I (at the same codeline) call it by usbSetInterrupt(0, 0); libUsb also retur...

Thanks =)

Thanks christian, that explains why it's there at all But because of USB's single-master architecture "someone" still has to do the polling... Is that done by the host-controller or does the OS have to do this (which in turn would basically mean it's using some CPU-time, just better organi...

Hi, I'm currently looking at the RemoteSensor example because I want to create a device which should send data to the host "itself". I'm wondering where the advantages of an Interrupt-In are compared to simply polling the device through Control-Transfers. Looking at the host-code in the ex...