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hotshot05
06-04-2011, 08:26 PM
I finally made the USBAsp circuit.
But am facing some problems in the USBAsp circuit.

When I connect it to USB port, it says USB device not recognised. I checked the whole circuit. found no problems.

Then I connected it to USB port and then measured the voltages at different points. the only place where there is an anomaly is between points 3 and 4 in USB input i.e the place where the zener diode is connected across pt. 3 and 4. It shows 0V.
when I check between pts. 2 and 4, it shows 3.2V
I checked the zener diode between 3 and 4 and it was connected properly.
It was properly shorted. so how should I check for the problem?

dheeraj91
06-05-2011, 10:02 AM
Can you see the green led on the usbasp turn on as you connect the usbasp to the usb port.

hotshot05
06-05-2011, 02:55 PM
No, none of the LED s are glowing.
The voltage drop across the LED s are too low.

hotshot05
06-05-2011, 05:17 PM
Tried burning another atmega8. This time both the LED s are glowing. But still it says USB device not recognised.

But I burnt this A8 with hfuse=C9 and lfuse=EF (as mentioned in make file of USBAsp)
[you had suggested hfuse=E9 and lfuse=EF]

Now when I try to change the fuses, this happens
http://img855.imageshack.us/img855/8849/fusebits1.th.jpg (http://imageshack.us/photo/my-images/855/fusebits1.jpg/)

whenever i choose yes, nothing happens, avrdude stops in command line.
but if I choose n, avrdude completes and shows success.

Why am I not able to change the fuses?

hotshot05
06-06-2011, 01:13 AM
I was checking the oscillator pins.
A strange thing is happening. If I check the voltage at each oscillator pin with respect to ground, I get 0V. But if I check each pin of oscillator with respect to Vcc, I get 2.3V.
the voltage across ground and Vcc is 5.2V.

What is happening?

asimov_18
06-06-2011, 02:06 AM
hotshot r u at IITB?

Asimov

dheeraj91
06-06-2011, 06:43 AM
Try plugging the usbasp onto a different usb port.And also on another system.

Just one led will be on when the usbasp is connected to the usb port.

hotshot05
06-06-2011, 03:03 PM
Try plugging the usbasp onto a different usb port.And also on another system.

Just one led will be on when the usbasp is connected to the usb port.
I plugged it into both my laptop and PC. same result everywhere.
Which LED should glow? The red one?
When is the green LED supposed to glow?


hotshot r u at IITB?

Asimov
Nope. I dont study there.

dheeraj91
06-06-2011, 08:09 PM
The red one should be glowing.I interchanged those two on my usbasp, so told you to check for the green one.

Avinash Nagaraj
06-06-2011, 11:10 PM
Before you connect the device into the port you need to install drivers for that device,otherwise the PC will not recognize the device...

hotshot05
06-08-2011, 03:22 AM
The red one should be glowing.I interchanged those two on my usbasp, so told you to check for the green one.
Can you mention the atmega pin to which the LED which is supposed to be glowing is attached?


Before you connect the device into the port you need to install drivers for that device,otherwise the PC will not recognize the device...
But in all the sites, I have seen that the device is first recognized, and then Windows prompts for the drivers.
And the driver is in the form of an inf file, how can I install it from beforehand?

dheeraj91
06-08-2011, 05:56 AM
The led connected to PC0 must be glowing when you connect it to the usb port.

And also , you can install the drivers only once the usbasp is getting detected by the system and windows prompts for the drivers.Try plugging your usbasp into another usb port of your system.