The pull-up or pull-down resistor on D+ is not so relevant, it should prevent stray interrupts when the computer is not connected.
You can verify clock and crystal settings with a test loop, e.g.:
This should generate a 1 Hz signal on the port pin. You can check it with an LED.
The error message is very generic: It means that USB does not work at all (except the pull-up resistor). So it can be almost anything...
You can verify clock and crystal settings with a test loop, e.g.:
- for (;;) {
toggle_port_pin();
int i;
for (i = 0; i < 1000; i++) {
_delay_ms(0.5);
}
}
This should generate a 1 Hz signal on the port pin. You can check it with an LED.
The error message is very generic: It means that USB does not work at all (except the pull-up resistor). So it can be almost anything...