I am new to AVR so hope u dont mind my stupid question in the circuit of usbasp can any1 explain me wht is the use of 68 ohm resistor(other thn current limiting) which is connected between USB and PORTB of atmega 8 can i use any other resistor???
Friend, refer to this topic . It contains all the information u need...I have built 1 USbasp & have uploaded the modified & Perfectly Working schematics & layout using Target PCBpool...Even i have changed some resistor values...Download the file...Itll help u...Regards
sidy thx a lot for help but i am unable to open the files cause i dont have target pcb can u just send me the circuit diagram like given in 8051projects site.....if its possible for u....thx once again
Vishal m very sorry...I dont have access to PC right now, m browsing through my smartphone...But u can open those files...Google for "Download Target PCBpool dicovere"...and download it...u can open them using this software also it is good PCB designing software...Hope it helps...
Sidy i did test he circuit today it showed "windows cant recognize the device" i did install the usbasp driver from net but still it showd tht.....need help ......i have made the circuit according this site https://www.fischl.de/usbasp/
Sidy i did test he circuit today it showed "windows cant recognize the device" i did install the usbasp driver from net but still it showd tht.....need help ......i have made the circuit according this site https://www.fischl.de/usbasp/
You didnt mention that wether you have constructed the circuit o a PCB or on a vero board. There are quite a lot chances of swapping the USB communication Pins when the circuit is assembled on a veroboard. Cross check the same which is a common mistake. Also confirm that you have programmed the correct fuses on the firmware chip as per the article.
Cheers
I guess the thing is tht i think so atmerga 8 wasnt programmed properly...i m makin serial programmer again in order to program atmega 8 first....any comments???
Vishal refer to this topic, before programming the Atmega8 u have to set its fuse bytes, load the hex file & then program the IC.This post has a pic displaying the fuse bytes then after that pranam made a post, telling the exact Fuse Bytes to be programmed..
sidy am programming atmega8 using avrispmk2 as i dont have a serial port...tht means i need to vary the circuit given by fischl according to avrisp rite???
Buddy ur programming circuit has nothing to do with the Fischl's circuits...Whther u program the Atmega8 by USB programmer or any other programmer just take care, u program properly with appropriate fuse bytes...u cannot program the atmega8 when it is in the Fischls circuit...program it separetely on a breadboard or the way u find convienient...then put the programmed Atmega8 in the main circuit (Fischls circuit) & now when u connect the USBasp to Pc ...it would ask for driver...