avrisp mkii clone firmware working on PC but not in Laptop

[shamikrudra]

I am using AvrMini avrisp mkii clone firmware in usbasp hardware
it is working fine on my desktop but not working on my laptop
laptop identifies the device as avrisp mkii but avrstudio not able to communicate with it
but same hardware is working on my laptop when using usbasp farmware.
can anybody pls identify the problem?
what is the defrence in communication in avrisp mkii and usbasp?

 

[wp100]

Hi,

Peope with the Pickit2 programmer using a laptop sometimes have a similar problem.

Its usually caused by the USB voltage on a laptop being too low, the solution is to use an externally powered USB hub so the programmer gets a good 5v

 

[nandhu015]

I am using AvrMini avrisp mkii clone firmware in usbasp hardware
it is working fine on my desktop but not working on my laptop
laptop identifies the device as avrisp mkii but avrstudio not able to communicate with it
but same hardware is working on my laptop when using usbasp farmware.
can anybody pls identify the problem?
what is the defrence in communication in avrisp mkii and usbasp?

Are you sure both laptop and desktop have the same version of AVRSTUDIO installed.

Better try reinstalling the AVR Studio in the laptop

 

[shamikrudra]

Avrstudio version is same on both 4.18 With sp3 also tried with 4.17 result are same
I can not blame the hardware because same is working with usbasp farmware.
after study i found that bulk transfer can fail on laptops.
can I change any thing in code to try in laptop? if yes where bulk transfer code is in V-USB.

 

[shamikrudra]

Can any one tell me from where 68 ohms value comes for usb data lines? it is current limiting resistance? what is the formula for this value?