I have before me the task to write down on a clean 5V 16MHz Atmega 328Pchip the bootloader optiboot to be able to use the watchdog function. Then block access to the reading of the chip bootloader and my Arduino-based program sketch.
I have a clone USVasp by Thomas Fischl. I found only one program that works with windows and USVasp - AVRDUDESS (http://blog.zakkemble.co.uk/avrdudess-a-gui-for-avrdude/). If I understand correctly, the procedure is as follows:
connect the programmer, the programmer adjusts the settings, the type of microcontroller.
write bootloader optiboot_atmega328.hex from https://github.com/Optiboot/optiboot/tree/master/optiboot/bootloaders/optiboot and check after the recording.
3.write the Fuses and verify: EXTENDED - 05 HIGH - DE LOW - FF
- change LB from 3F to 0F and write and verify
5 write sketch in HEX with the “Disable flash erase (-D)” option set and verify
6.set new LB.
!!! What should be the LB that could not be any way to read my sketch and bootloader?