I just came across to another way of bootloading ATmega8: probably the best.
There is a Github (https://github.com/MCUdude/MiniCore) that is supporting bootloaders for ATmega8, ATmega48, ATmega88, ATmega168 and ATmega328.
There is also support for other AVRs , check https://github.com/MCUdude
All you have to do is install the library and bootload using another Arduino (Arduino as ISP). I’m still having trouble with my USBtinyISP programmer; it seems that there is a compatibility issue between avrdude 6.3 and USBtiny.
Upload your Arduino UNO with the “Arduino as ISP” sketch using an Arduino IDE 1.6.5 or later.
Use following setup to bootload an ATmega8:
Go to Tools, click Burn Bootloader and you are done!
Test using FTDI chip:
Once the target chip (ATmega8) has the bootloader, just load your code through a normal serial connection. It requires the following:
Use a 0.1uF cap between DTR and the reset pin. From there, all you need are 4 pins to connect to the target circuit – Ground, reset, Tx, Rx. This way you don’t need another Arduino to load code, and the serial monitor will work through the same hardware. Use any Arduino IDE!!
Connect FTDI connector as serial
- DTR to pin 1 via 0.1 uF cap
- Reset pin1
- ATmega8 pin2 Rx connect to FTDI Tx
- ATmega8 pin3 Tx connect to FTDI Rx
- Tools menu:
- Serial: Choose your COM port
- Board: Atmega8 within MiniCore menu.
- Choose BOD =2.7V; Clock: 8 MHz external
- Programmer: Arduino as ISP
- Upload blink sketch!!
- Upload using programmer, i.e., shift + upload arrow
You are done!