After success full implementation of serial programmer, I turned to make a USBasp programmer .The firmware is downloaded from USBasp official site.In this tutorial we will see how to use AVRdude for burning hex files into AVR microcontroller using USBasp. USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega8 and a couple of passive components. The programmer uses a firmware-only USB driver, no special USB controller is needed. In my circuit only use the six pins(MOSI,MISO,SCK,RESET,GND,+5V) from the usbasp to target microcontroller, It is little different from actual circuit in official site. No need of external +5V power supply to target microcontroller. The circuit is given below |
| USBasp programmer |
NOTE:The fuse bits for 12Mhz crystal HFUSE=0xc9 and LFUSE=0xef burn explicitly to atmega8 using serial programmer(any programmer).It is very important, the USBasp programmer cannot work with default fuse bits. The command for setting the fuse bit:
avrdude -c ponyser -p m8 -P /dev/ttyS0 -U lfuse:w:0xc9:m -U hfuse:w:0xef:m
For reading the current fuse bit in atmega8:
avrdude -c ponyser -p m8 -P /dev/ttyS0 -U hfuse:r:high.bin:b -U lfuse:r:low.bin:b
