I have bought an atmega328p-pu which has a bootloader on it(amazon says so). But when I upload sketch on it, it says yikes, invalid device signature. How can it say that for p-pu? I thought it was for 328pu.I do this my making a standalone arduino on breadboard.
I also have the atmega328-pu. I modified the conf file also by replacing 0F with 14, but that too didn't work.
My arduino is working fine since I have uploaded sketches on it without any problems, but I am unable to use it as ISP.
I am using arduino 1.0.6. Here's complete information about the chip:-
atmel atmega328p-pu 1417
On the backside 4U1286 35473D 1-P1417 e3
The most likely culprit is wiring.
The second most likely culprit is the clock. Did you correctly connect a resonator or crystal + capacitors to the processor?