usb to serial and back on the fly with ucase$

[f_lez]

Ok I was thinking of a little project to test the old grey cells and to finally how to learn how to use USB as i am planning to need it soon, and sooner jump into a big project this seems easier....


Set usb on the pic to appear to windows as a virtual com-port


if available, read a character, from the virtual com-port, convert it to upper case, and then output it at 9600 via the hwuart....

and....

if available, read a character, from the hwuart , convert it to upper case, and then output it at 9600 via the virtual com-port


continue till the worlds end.

Now its all simple when written down, and i can easily achieve this if it was using the hwuart and a swuart, but i am lost with the usb side.

I think i'm in the same boat as alot of people on this, so can we do this simply, if usb is such a thing.....

I know there are lots of easy this and that and HIDeous things around, but the keyword is simple.....

Got a spare 18f2550 and a 4mhz crystal here i think may be just the ticket

[f_lez]

ok had a look at MCS and easyhid, tried to compile the output it generated, but i got an error that pbppic18.lib could not be found.


i added a line near the top, include ''pbppic18.lib'' but now get an error a redefinition of label of [ifndef]

never easy is it, even when its called easy.....

[f_lez]

Ok i found the easy cdcusb demo thingy....(technically minded me)

i eventually got it all copiling without errors once i fixed the paths in the 'incs'

but....

now i have another issue...

this is a segment of my test code

    portb=16+8
    pause 1000
    portb=8+1
    pause 1000
    USBInit
    portb=8

It gets to ubinit with all being fine, then the lights go out, and thats the end of it.....

if it was waiting at usbinit or stuck at it i would expect the lights to stay on...


anyone know why that happens, windows does nothing either.

[Darrel Taylor]

It looks like the External USB Transceiver pins are active. (VPO VMO etc.)

Have you changed the UCFG register?
You should not.

[f_lez]

It looks like the External USB Transceiver pins are active. (VPO VMO etc.)

Have you changed the UCFG register?
You should not.

it has a ucfg register? i just downloaded the usbcdc demo and compiled it, when i said i fixed the incs i meant the inc issue with the 18f2550 fuses and the invalid path in one of the incs i found.



by flashing the leds on portb etc i know i am running internally at the right speed so my clock divs are ok.

all i have is pic on a board with leds on the ports and a usb connector, nothing fancy, was hoping to achive success with the KISS principle..

precompiled stuff seems to work, i used this board about two years ago with the simple usb demo, but i need to make it do serial...

I did just find another path {c:\pbp\pic¬1.47\} that i need to edit but the phone just went and i have to go drive someone shopping!

thanks for the reply, i'll update when they stop dragging me back to the real world

[f_lez]

ok now i want to scream at it..........

buffer	Var	Byte[16]
cnt	Var	Byte
flash var byte   

LED0	Var	PORTB.0
LED1	Var	PORTB.1
LED2	Var	PORTB.2
LED3	Var	PORTB.3
LED4	Var	PORTB.4
 
CMCON = 7            ; turn off comparators 
ADCON1 = 15            ; turn off analog inputs

define OSC 48

trisa=0
trisb=0

    high led0
    high led1
    high led2
    high led3
    high led4

pause (1000)
    low led4
pause (1000)
    low led3
pause (1000)
    low led2
pause (1000)
    low led1
pause (1000)
    low led0
pause (1000)  ; end of the pretty countdown


    portb=9
    pause 1000
   ; usbinit
    portb=8 
    pause 1000   ; never gets to here if i un-rem usbinit
    portb=16

; Wait for USB input
idleloop:
;   USBService	' Must service USB regularly
;	cnt = 16	' Specify input buffer size
    
    if flash=0 then
	portb=1
	flash=1
	else
	portb=0
	flash=0
	endif
;	
;   USBIn 3, buffer, cnt, idleloop

pause 1250
    goto idleloop

with the usb bits rem'd out, the led's flash as expected, as soon as i un=rem usbinit, it hangs at usbinit

[f_lez]

actually, after displaying '9' on portb, it goes immeditaly to showing '1', and i mean immediate, no one second pause displaying '8'

to get to '1' it must pass '8', but then if it got to '1', it should flash between '1' and '0'.........and it does not - ant that last pause is 125 not 1250........

now i am confused