abacusdheda
Junior Member level 1
Problems with USBASP
i had used usbasp earlier, belonging to one of my friend, now when i tried building it myself i am getting usb hardware not recognized error. i checked with circuit connections zillions of time, no connection error, swapped D+ D-, but no relief. checked with zeners which looked ok on the face of it(simple DMM test). crystal was correct 12Mhz(ran simple test program). put all possible noise blocking capacitors. found red LED glowing which means the Atmega8 working properly.Then i came across a post by sidy50 & other people who said that they successfully made it. i checked with their this diagram**broken link removed**
the differences i found was that i used 22pF caps with crystal as given fischl.de site
instead of 27pF and i put 2.2k pullup instead of 1.5k, else all same.
i want to ask how much will it make difference if i put pullup resistor which has value lesser by 0.7k and caps with 5pF more capacity(even datasheet recommends caps in the range 12-22pF)
losing all hopes on usbasp
P.S. my design has lots of wires and all crammed into a small PCB, but trying it on breadboard also does not seem to work
i had used usbasp earlier, belonging to one of my friend, now when i tried building it myself i am getting usb hardware not recognized error. i checked with circuit connections zillions of time, no connection error, swapped D+ D-, but no relief. checked with zeners which looked ok on the face of it(simple DMM test). crystal was correct 12Mhz(ran simple test program). put all possible noise blocking capacitors. found red LED glowing which means the Atmega8 working properly.Then i came across a post by sidy50 & other people who said that they successfully made it. i checked with their this diagram**broken link removed**
the differences i found was that i used 22pF caps with crystal as given fischl.de site
instead of 27pF and i put 2.2k pullup instead of 1.5k, else all same.
i want to ask how much will it make difference if i put pullup resistor which has value lesser by 0.7k and caps with 5pF more capacity(even datasheet recommends caps in the range 12-22pF)
losing all hopes on usbasp
P.S. my design has lots of wires and all crammed into a small PCB, but trying it on breadboard also does not seem to work
