Objective Development Forums 2008-04-23T09:30:15+02:00 https://forums.obdev.at/app.php/feed/topic/1282 2008-04-23T09:30:15+02:00 2008-04-23T09:30:15+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5150#p5150 <![CDATA[AVR_USB timing out?]]>
1.95 V is far below the limit of 2.5 V. Please use higher voltage and lower power diodes. You should reach AT LEAST 2.5 V.

Statistics: Posted by christian — Wed Apr 23, 2008 9:30 am

]]> 2008-04-22T23:52:20+02:00 2008-04-22T23:52:20+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5146#p5146 <![CDATA[AVR_USB timing out?]]>
christian wrote:3.3 V Zener diodes are not a very good idea. Can you please measure the voltage level on D-? Is it well above 2.5 V?


Yes, I have measured. Between VCC and D- voltage 3.15V, between GND and D- voltage 1.95V. It is normal? No?
Also before your post I have changed connection 1.5K pullup resistor from VCC to pin on MCU and change firmware as it was recommended earlier:

Code: 

int main(void)
{
    uchar i;
    usbInit();
    /* enforce USB re-enumerate: */
    usbDeviceDisconnect();  /* do this while interrupts are disabled */
    for(i=0;--i;){          /* fake USB disconnect for > 250 ms */
        _delay_ms(1);
    }
    usbDeviceConnect();
    ....
    sei();
    for(;;){ /* main loop */
        usbPoll();
        ....
    }
}


defined USB_CFG_PULLUP_IOPORTNAME, USB_CFG_PULLUP_BIT also.

it has worked some days, and I was already happy, but... again all has repeated.
One more interesting thing. The program(firmware) thus works, as the light-emitting diode blinks in cycle... but usb-connection is down.

Thanks for help, christian.

Statistics: Posted by centrino — Tue Apr 22, 2008 11:52 pm

]]> 2008-04-21T10:39:01+02:00 2008-04-21T10:39:01+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5121#p5121 <![CDATA[AVR_USB timing out?]]> Statistics: Posted by christian — Mon Apr 21, 2008 10:39 am

]]> 2008-04-19T00:34:41+02:00 2008-04-19T00:34:41+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5107#p5107 <![CDATA[AVR_USB timing out?]]> My board with mega8 mcu used for retrieve data from dallas 1-wire temperature sensor and next to computer. I'am use "commandline" program from powerswitch distributive with some tiny changes. About 5-10 hours it's works is fine then i have -
"Warning: cannot query manufacturer for device: error sending control message: Input/output error".
Used OS - FreeBSD 7.0-STABLE.
In system logs no messages about connect/disconnect.
Only disconnect and connect by hand enables board for further operate...
I'am use zener diode on D+ and D-... hmm 3.3v.

and i'am use usb drivers from last powerswitch (2008-02-28)

P.S.: Sorry for bad english.

Statistics: Posted by centrino — Sat Apr 19, 2008 12:34 am

]]> 2008-04-14T20:16:34+02:00 2008-04-14T20:16:34+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5042#p5042 <![CDATA[AVR_USB timing out?]]> Statistics: Posted by christian — Mon Apr 14, 2008 8:16 pm

]]> 2008-04-14T20:14:45+02:00 2008-04-14T20:14:45+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=5040#p5040 <![CDATA[Re: same problem here]]>
xtremely wrote:

Code: 

    while (--j) {               /* USB Reset by device only required on
                                   Watchdog Reset */
        i = 0;
        while (--i);            /* delay >10ms for USB reset */
    }


I have seen many problems with this construction after switching to a newer avr-gcc (based on gcc4). The delay loops get optimized away. Use _delay_ms from util/delay.h instead.

Statistics: Posted by spiff — Mon Apr 14, 2008 8:14 pm

]]> 2008-04-08T09:45:21+02:00 2008-04-08T09:45:21+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=4945#p4945 <![CDATA[AVR_USB timing out?]]>
See my posting here for details:
http://forums.obdev.at/viewtopic.php?t=1202

Tom

Statistics: Posted by iphi — Tue Apr 08, 2008 9:45 am

]]> 2008-03-28T14:56:46+02:00 2008-03-28T14:56:46+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=4804#p4804 <![CDATA[AVR_USB timing out?]]>
So it is normal that my device might dsconnect and then connect again without getting into trouble with the client program sending commands to the device?

No, this is not normal. But IF you get these resets, you can at least fight the symptom and write the firmware, driver and application so that a reconnect is possible.

We now recommend the following sequence (requires the newest driver version so that usbDevice[Dis]connect() works as it should):

Code: 

int main(void)
{
    uchar i;
    usbInit();
    /* enforce USB re-enumerate: */
    usbDeviceDisconnect();  /* do this while interrupts are disabled */
    for(i=0;--i;){          /* fake USB disconnect for > 250 ms */
        _delay_ms(1);
    }
    usbDeviceConnect();
    ....
    sei();
    for(;;){ /* main loop */
        usbPoll();
        ....
    }
}

Statistics: Posted by christian — Fri Mar 28, 2008 2:56 pm

]]> 2008-03-28T12:41:36+02:00 2008-03-28T12:41:36+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=4802#p4802 <![CDATA[same problem here]]> I got the same problem here. I removed the zener diodes, but my device is still not reachable after about half an hour.
If your firmware restarts at main(), you must have some kind of reset. This can be a brownout-reset, a watchdog reset or a spike on the supply line or RESET line which causes a hardware reset.

So it is normal that my device might dsconnect and then connect again without getting into trouble with the client program sending commands to the device?

This disconnect should last for at least several 100 ms so that the host detects it reliably. Old reference projects had only a couple of milliseconds and many example projects still have this short disconnect period.


in the code I can see this part:

Code: 

int main(void) {
    uchar i, j;
    odDebugInit();
    DDRD = ~0;                  /* output SE0 for USB reset */
    PORTD = 0x00;               /* no pullups on USB pins */
    DDRC = 0xff;                /* all outputs */
    PORTC = 0x00;

    j = 0;
    while (--j) {               /* USB Reset by device only required on
                                   Watchdog Reset */
        i = 0;
        while (--i);            /* delay >10ms for USB reset */
    }
    DDRD = ~USBMASK;            /* all outputs except USB data */
    TCCR0 = 5;                  /* set prescaler to 1/1024 */
    usbInit();
    sei();

should I try to replace the while (--i); with a delay for about 200ms? (sry but i'm quite new to microcontrollers and programming stuff)

Statistics: Posted by Guest — Fri Mar 28, 2008 12:41 pm

]]> 2008-03-17T12:37:10+02:00 2008-03-17T12:37:10+02:00 https://forums.obdev.at/viewtopic.php?t=1282&p=4631#p4631 <![CDATA[AVR_USB timing out?]]> Statistics: Posted by christian — Mon Mar 17, 2008 12:37 pm

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