USBSERVICE + serout2 problem

[Darrel Taylor]

Try moving the USB enable to after the initialization.

;    INT_ENABLE  USB_INT
ENDASM

;----[Initialise USB and Interrupts]----------------------------------------
    PAUSE 100                    ; Allow VUSB to stabilize
    USBINIT                      ; initialize the USB driver
    USBSERVICE                   ; service it once
    UIE = $7F                    ; enable USB interrupts
    UEIE = $9F                   ; enable USB Error interrupts
@ INT_ENABLE  USB_INT

Enabling before USBINIT probably wasn't a good idea on my part.

And while USBSERVICE is a PBP statement, the code is all ASM and does not use any of PBP's system variables. So change it back to ASM "type".

[aberco]

Hmm that make sense... I made the changes but that doesn't work any better though.

A little troubleshooting, if I plug the USB connector halfway (just Power) the LED blink, however it stops a couple 100's ms after D+/D- get connected.

[Darrel Taylor]

I may have asked you this in another thread, sorry if I did ... but ...

What size capacitor do you have on VUSB.
0.22 - 0.47uF?

[aberco]

Hardware is fine, USB does work with DT_HID260. I have two prototype boards with 220nF, both are ok. Config fuses are OK too, should be software-related.

[Darrel Taylor]

Well, I've got a 14K50 here now, and it enumerates and holds the USB just fine.
So far I haven't got a single blink out of RC3 yet though.

Not sure what's going on there, but I'll play with it some more tomorrow.

I'll add some USBIN/USBOUT statements too and make sure CDC is really working.

What operating system are you using?
Win7-64 here.

[aberco]

Well yeah, you're right! it does enumerates!!! and it even blink on my application.

What's happening, this is due to my programming setup and the specific hardwiring of the 18F1xK50. The USB lines D+/D- are shared with PGD and PGC, and it seems that in order for USB to work, the programmer has to be disconnected. For this purpose, I have purchased microchip special module for the 18F1xK50, that adapt the programming levels of the programmer to something that the PIC can accept, but at the same time allows to leave plugged the USB cable of the host computer by protecting the D+/D- lines from programming voltages.

Well I realized early on that it did not work, and I had to disconnect PGD and PGC in order to have USB working, so I added a set of switches on my programming cable.

Now I've been able to verify different behavior on USB programs, especially DT_HID260 which is the only one "powerful" enough to enumerate even with PGD/PGC connected to the programmer. All others required those lines disconnected to enumerate.



Now, about your little CDC routine, it does work well with PGD/PGC disconnected. But when I connect them back the USB connexion drops and the PIC crashes. No big deal, but I'll have to make sure that communication is established when servicing, and especially turn it of before unplugging USB.

Now I'll try to add USBIN/USBOUT statements and play a bit with communication before building the full program around it. Thanks for your great help!

[aberco]

Well, more progress, and so far so good!
In understood that your program proposal is actually a stripped off version of your USB_ASM_Service routine. I have been able to use it within my program now, but calling the DoUSBSERVICE routine using the USB interrupt triggered by your interrupt routine.

So far so good, it does enumerate, and more importantly I have all the control options given by the connected state, Tx/Rx ready. The LED always blink regardless of what the USB is doing.

The only thing that seems to break the code is "DEFINE RESET_ORG 2048 ' Start code at $0800", I added this at the very top to be ready for the bootloader implementation (leaving 1 kWords available). Probably a problem of memory bank and interrupt...

Seems to work very well so far... I am not posting the code until it is ok with you.