usb_cdc_getc() returns 0 on PIC18F2450

[capnmatt]

HELP!!!

I am trying to get the USB port working on my PIC 18F2450. My code (posted Below) enumerates and the PC side seems happy.

I've written a VB2008 exe that sends one character to the virtual comm port then waits for one character to be returned.

My Pic code receives the one character and sends it right back out.

For some reason, the usb_cdc_getc() funciton seems to only return 0. The transmission from the PIC seems to work. I can hard code it to send integers from 0 to 255 and my VB code reads it okay.

Any thoughts from the community?

Code:
#include <18F2450.h>
#device adc=8

#fuses ECPLL,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL1,CPUDIV4,VREGEN
#use delay(clock=16000000)

#include <usb_cdc.h>

#define led1 pin_c6
#define led2 pin_c7
#define LED_ON output_high
#define LED_OFF output_low

int8 DATA_RX;


void main(){

LED_OFF(led1);
LED_OFF(led2);

usb_init();

while (true) {

if (usb_enumerated()){
led_on(led1);
if(usb_cdc_kbhit()){

DATA_RX = usb_cdc_getc();
usb_cdc_putc(DATA_RX);

}
}
}
enable_interrupts(GLOBAL);
}

[FvM]

usb_task() is missing - at least in the shown code. You can use a software USB monitor and check, if the intended data bytes are actually transmitted to the device.

[Gendrick]

Hi capnmatt, where can I find a VB code for USB port with PIC, thanks , my email is gendrick@cantv.net