USB on 18F2455 funky problem

[Mark J]

yeah im using a 4mhz xtal as theyre what I had handy at the time lol.
Im using your USB ints for controlling the USB and its set to 10ms interval on both the USB_POLLIN and USB_POLLOUT

Edit: USB interupts are running on TMR1

[Darrel Taylor]

Edit: USB interupts are running on TMR1

That should not be the case. They should run off of the USB interrupts.

[PJALM]

I don't know if this helps but I have had similar problems in the past and simply putting a capacitor from the USB V+ to GND worked every time. I always use a 0.1uF but it probably doesn't really matter what value.

[Mark J]

That should not be the case. They should run off of the USB interrupts.

Sorry Darrel, my mistake, the USB is running under the USB_HANDLER interupt, its my sub routine thats using TMR1 (late at night I posted that lol)

Will try the cap across the pins and see if that remedies the problem as it is a bit of a headache having to remove the LED light unit from where it is to access the pic so I can edit the settings etc.

Edit: just realised, do you mean the 5V to GND of the USB? as on my pcb (and breadboard) I never wired up the 5V as I dont need to use the 5v from the USB so thought better to be safe and not connect it anywhere on the PCB just in case the 2 different 5v sources made things go pop etc! Only pins wired on the PCB side for the usb port are the D+/D- and GND.

[PJALM]

Yes for some reason I have the same problem happen. Putting a cap across the USB V+ and GND seemd to fix it for me, I thought maybe it just needed some sort of load to make it work.

I don't seem to need it on breadboards either, very wierd.

[Mark J]

Will have to try that but agree that it is very weird!! Will let you know if it does it for me too.

[Mark J]

Amazing!! rebuilt the USB breakout board and put a cap across the 5v and GND and blow me it works! weird! but MANY MANY thanks for the info!!!

One (Almost) happy chappy