PIC18F4550 USB Problem

[MUHAMMAD_T]

I have made my own USB library, because i needed to use it with PIC and ATMEL chips. I'm testing it on the 18F4550 chip and it works just fine on ISIS Proteus, but when I plug the hardware into the PC, it gives unknown device notification. The USB does not even reset . The hardware is very simple so that I just need to enumerate the USB, all required capacitors are in position. Anyone can tell what to do?!
_________________
"EGYPT is not a country in which we live , EGYPT is a place that lives in us"

[Ttelmah]

The odds are frequency.
Proteus has no idea what frequency your oscillator or dividers gives, relying on _you_ telling it. The real PIC instead needs these to be right.

Also the Proteus USB library _is_ faulty. This is part of the reason for the post at the top of this forum saying 'no Proteus questions', because it will allow you to configure systems as 'OK', that can never work, and conversely will tell you something is OK, which isn't....

Other oter thing, Proteus does not handle correctly the capacitor on Vusb. You say 'all required capacitors r in position', but Proteus will accept capacitors on Vusb, that won't work on the real chip. You want something like a 0.22uF, or 0.47uF polyester _not_ an electrolytic.

As a comment, are you using sensing on Vusb?. Technically, this is actually _required_ by the USB spec, with this requiring the peripheral to not wake up on the bus, until this line is seen, but a lot of the 'demo' programs allow you to not use this, which can cause problems in the real world.

Post your fuses, and what crystal you are using.

Best Wishes

[MUHAMMAD_T]

Well, the compiler is CCS, and I'm not using the built in library. I made my own. I use interrupt, not polling, which is safer I guess. The fuses are:

[temtronic]

Honestly if the hardware is all ok...use the CCS supplied USB test programs in the examples folder. I _know_ that they do work.

Once you confirm that your hardware works with the CCS USB programs,then install your code and see what happens.

hth
jay

[MUHAMMAD_T]

I did that with the ex_usb_hid, and the problem was the same. Well, if you can supply a schematic just for enumeration, and a TESTED code that you made and it worked, I would be thankful. Thx in advance.
THX temtronic for replying.
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"EGYPT is not a country in which we live , EGYPT is a place that lives in us"

[drolleman]

You need to do the work.

If the ccs example didn't work, your hardware is not correct.

Start there...

[Avinash P]

I have developed a program to interface PIC18F4550 with PC using USB.
The code shows 18 errors, Please help me to resolve the issue.

My code:

[Ttelmah]

Comment in the code:

[Avinash P]

I have tried the changes mentioned by you.
Now all my errors are cleared.
Going to fuse the program!
Once again my sincere thanks.

[Avinash P]

hi,
i am testing my hardware now, my hardware is got powered by USB by its not detected by PC,
whether i need to implement On the Go protocol in my pc or the problem may be with my code or hardware ?
MY EDITED CODE

#include <main.h>
#include <stdio.h>
#include <stdlib.h>
#include <usb_cdc.h>
//#include <USB.h>
//#include <pic18_usb.h>
//#include <usb.c>

#include <lcd.c>

#byte PORTA=0xF80
#byte PORTB=0xF81
#byte PORTC=0xF82
#byte PORTD=0xF83
#byte PORTE=0xF84

#byte TRISA=0xF92
#byte TRISB=0xF93
#byte TRISC=0xF94
#byte TRISD=0xF95
#byte TRISE=0xF96

#define USB_CON_SENSE_PIN PIN_B2


char dat;

void main()
{
setup_timer_3(T3_DISABLED | T3_DIV_BY_1);
TRISB=0x00F;
dat=100;

lcd_init();
usb_init();

while(TRUE)
{

if(usb_attached())
{
lcd_putc("\f USB DETECTED");
delay_ms(100);
usb_task();

if(usb_enumerated())
{
lcd_putc("\f USB ENUMERATED");
usb_puts(0,dat,8,100);
}
delay_ms(100);
} //TODO: User Code
}

}

pls help me
Thanks in advance

[temtronic]

Honestly, you _must_ install the CCS USB example programs and confirm they work with your hardware.
1) you do not need OTG(OnTheGo) USB to make a 4550 work with a PC.

2) hardware...do you have the correct 'sense' resistors/hardware for the 4550?

3) PS side...correct 'driver' installed and running , have you tried USBVIEW.exe?

Anyone trying to help you will have first installed and tested the CCS supplied examples as we KNOW they WORK.USB is NOT easy or simple.

Your code might be ok...but have a bad hardware setup...
Your code could be bad...and have a hardware problem..
Your code can either be right or wrong but your PC software is bad...

There are too many choices for anyone here to say 'this' is the 'problem'.

Please , install the CCS USB examples and reply with the reults, then we can narrow down what's going on.

hth
jay