UASBASP is very nice programmer for Atmel AVR microcontrollers that works under multiple operating systems including Linux, Mac OS X, and windows. How to assemble this simple programmer read previous article in this site or go to original site of Thomas Fischl.
As it was mentioned mentioned USBasp has two available programming frequencies – high when jumper disconnected and low when connected. These frequencies are 375kHz and 8kHz. In order to use 375kHz speed, target MCUâ€™s clock frequency has to be at least 1.5MHz – four times higher than SCK. If target is clocked with low speed oscillator like 32kHz then jumper has to be connected as it gives 8kHz SCK which is also 4*8kHz=32kHz.
Building and preparing this programmer should not be a problem as it uses very few components. If you use 6 PIN ISP header, then you need 10 to 6 adapter. Flash Atmega8 with newest firmware found in authors site. Right now newest firmware is 2007-10-23. For other details read in readme file.
If device was soldered correctly then its time to put it on action. First of all connect USBASP adapter directly to PC USB port â€“ avoid hubs! Install necessary driver like it was described here. Then connect ISP header to target board and power it up. Now we are all set.
Programmer supports open source AVRDUDE programmer since version 5.2. so your latest WinAVR tolls set has it. Now lets try to run programmer in terminal mode. For this go to command line by pressing Start->Run and type cmd. In command line type command line:
avrdude -c usbasp -p atmega16 -P usb -t
and press enter and see what’s happening:
Programmer reads targets signature and waits for further commands. To exit terminal mode type quit.
Now when we are sure that programmer works OK, lest set up WinAVR project to compile and flash code just in one click. For this you need to edit makefile. Just use Mfile editor which comes with WinAVR installation and edit following lines:
AVRDUDE_PROGRAMMER = usbasp
AVRDUDE_PORT = usb
That’s it for setting programmer. Now select [WinAVR] Program from Programmers Notepad Tools menu and enjoy the rest â€“ make.exe takes care of the rest: compiling, flashing and verifying.
Last notice. Don’t expect high programming speed as it uses firmware only USB driver. Maximum of this programmer is up to 5kBytes/s. And seemed that it is a little bit faster comparing to my LPT ISP programmer. I think not a speed is main key here, but ability to use USB port which is the only choice in some computers especially laptops.