Software on PIC will come in loop after disconnect USB connection

[Squibcakes]

Hi DT,

Great! I tried this one and it works. Good one.

However, I've tried to incorp. it into an existing program and it doesn't work.

Your code seems to indicate that the USBSERVICE routine is continually called by the USB_int handler. How often does this interrupt? Only when it is plugged / unplugged or all the time?

The problem is that I'm servicing the USBSERVICE through a 1msec Timer1 interrupt handler and trying to read the flags in that interrupt but they don't set.

'---[TMR1 - interrupt handler]---------------------------------------------------
USB_SERVICE:                    ' COMES HERE 1msec TO SERVICE THE USB PORT
        
     T1CON.0 = 0                ' TURN OFF TIMER                 
        TMR1L = COUNTER1.byte0  ' RELOAD TIMER  LOW
        TMR1H = COUNTER1.byte1  ' RELOAD TIMER HIGH
        IF IDLEIF THEN Plugged = 0
        IF SOFIF  THEN Plugged = 1
        USBService	            ' KEEP USB ALIVE
     T1CON.0 = 1                ' TURN ON TIMER
    
    
@ INT_RETURN

The way I see it is that SOFIF should always be set since I'm servicing USB every 1 msec untill I disconnect the USB cable.

I would do away with the Timer1 Interrupt altogether and use USB_INT but how often does the USB_int get called?


Cheers
Squib

[Darrel Taylor]

Using the USB_INT source is much more efficient than using a 1ms timer.

During Enumeration it may only be a few microseconds between interrupts, and there are a lot of them. Consequently, it connects to the PC much faster.

But during normal operation, it drops to about every 10-20 milliseconds, although that depends on the polling time set up in the descriptor.

When the cable is un-plugged, you don't get any USB interrupts at all (after the IDLE int).

Plus using the USB_INT frees up a Timer.

ADDED:

But that doesn't explain why the Plugged example above doesn't work with the Timer Interrupts. It should work.

Are there any other USBSERVICE statements in the program?
There should only be 1.

[Squibcakes]

DT,

What you say makes sense and I like the fact that it frees up a Timer.

I found in my original program that I missed (during a cut and paste) the section where you loaded UIE and UEIE with values... which would explain why it wasn't running with my timer ints....

The whole point of this exercise is to "error trap" the pic for any unforseen conditions, eg I've seen the PIC hang sometimes when shutting down pc coms programs that don't close the port nicely. Hopefully this will stamp that one out. LOL

Now, since you have all the answers, do you have tonight's Lotto Numbers by any chance?

Cheers
Squib

[Darrel Taylor]

... do you have tonight's Lotto Numbers by any chance? ...

Oh sure ... Here's the numbers for California's Super Lotto Plus, for all future draws.
Just come back here before each game for the new numbers.



Of course it would have been better, had you asked for "tonight's Winning Lotto Numbers"!

[Art]

Lol,
NVM. if the game is played long enough, they'll win at some stage.