usbasp / mac os x

[statops]

Hi,

I'm having trouble getting os x to recognize my usbasp.

When I plug the board in, system.log shows:

Apr 14 14:34:10 mbpro kernel[0]: USBF: 2072.978 [0x3de9200] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 1 of hub @ location: 0x1d000000)
Apr 14 14:34:16 mbpro kernel[0]: USBF: 2079.251 [0x3de9200] The IOUSBFamily was not able to enumerate a device.

I am using zeners on D+ and D-. (1N5227)

Any suggestions?

[christian]

Please measure the voltage level on D- when the device is idle. It should be well above 2.5 V and below 3.6 V. Some Zener diodes are not suitable.

[hoho]

what voltage should there be on D+ then?

[christian]

Less than 1 V when there is no traffic on the USB.

[hoho]

The voltages are within these ranges, but still no joy. My ds1820 adapters don't want to work. (the same error as ts)
On some schemes there's a pull-down(?) resistors on d+ line, on the others there is no resistor. Does it make any difference? What are the usual fuse settings for v-usb (external crystal means cksel=1111, sut=11? what else should I check?

[christian]

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.:

Code: Select all

    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...