I was trying to burn my atmega328p board which is designed for some wireless application. The ICs atmega328p, esp8266 12f, and ADM7171 are using the same Vcc. Here the Power supply is connected to LT3682 and the output of the same is shared by the above said ICs.
I have used ProgISP tool and USBasp programmer. The board that I have used was already programmed by another person. So the fuses are already set.
After connecting and verifying the connections. I clicked RD button on progisp and output was ok. so the atmega328p is detected and thereafter I verified the fuses and it was ok. Then burn the flash with my hex code, but at this time it gives me a verify 0 error.
After getting that error, Atmega328p is not detecting on USBasp programmer. I have also changed the tool to avrdudess but it have the same problem.
The one problem that I was observed is that, while writing the flash USBasp programmer was at 5V. Is that any problem? After noticing this, I have changed that to 3.3v and again tried to burn the flash but the same happened atmega328p is not detecting.
Is that any fuse locks? But I haven't done anything to fuse bits, I have just read that. I have also double-checked the connections and the programmer is good since I can burn the flash of the other board.
For programmer at 3.3v, I observed following voltages.
Vcc - fluctuating 2.23-2.31 RST - 2.22
These voltages are not constant, sometimes it varies.