Instant Interrupts - Revisited

[Darrel Taylor]

The only case that is still at issue for me is that the device doesnt go passed the "DoUSBinit" subroutine if it's powered on while not connected

Yeah, when it's not connected, it'll never make it to the CONFIGURED_STATE.

Change the Init routine to this.

DoUSBinit:
    pause 500
    usbinit                  ; initialise USB...
    USBSERVICE               ; service it once
    UIE = $7F                ; enable USB interrupts
    UEIE = $9F               ; enable USB Error interrupts
    @ INT_ENABLE USB_INT
return

[RYTECH]

Thanks Darrel that did it for me!

[RYTECH]

Does the USB operation of the 18F4550 have a direct effect on the A/D channels..? Let me explain why i ask....

Case a) when i power up my circuit the A/D values float - not 200 or 300 millivolts - which for my inexperience, hackjob craftsmanship, and source voltage reference would be acceptable, but sometimes, usually when i power up without the usb cable connected, the values float sometimes as much as 800 millivolts on my 12v line, i've metered the several points, there's no floating, so it's something to do with the IC's operation. I can usually correct the issue by plugging in the device and unplugging it. I'm stumped as to what exactly is going on... i'm wondering if this 800 millivolt swing has something to do with the pic enabling or disabling its internal pullups on the usb data lines. it seems to revolve around the state of the usb connectivity... when the problem is not present my readings are mostly acceptable, the caps and aquisition times seem to work ok.

wonder whats going on... i think i chose the wrong IC for my solar powered charge controller... I really like the usb connectivity, but the IC with only 1 power led and 1 led that flashes every so often (about 1/16 cycles through main) the circuit draws about 120 mA... is that around normal for not having any sleep cycle in main? I tried to activate the WDT to implement a sleep but it seems the USB bootloader (or something) doesnt like it, cause when i reset the chip after the WDT enable change the USB reports the device is not recognized....

[RYTECH]

so i guess i actually have 2 issues still, i cant sleep (neither can my device) and the A/D sometimes acts "wonky" depending on the state of the usb pluggedness.

[Darrel Taylor]

I've never tried to put a USB PIC to sleep.
But the datasheet has some warnings about putting the USB module in "Suspend" mode before going to sleep, and using the Resume bit to "wake-up" on USB activity.
See section 17.2

Could be tricky.

120ma sounds pretty high.
Try disabling the USB module and VUSB regulator and see if that's where it's comming from. The datasheet doesn't seem to list the current for the USB module.
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