Hi all, This will be my first post, but I've been reading the forum's for quite some time. I'd like to thank everyone in advance for all the things I've learned on these forums. This one has me stumped.
I purchased a few atmega328p-pu chips on ebay, supposedly with the bootloader preloaded on them.
I hooked them all up to the breadboard (one at a time of course) per the instructions on this site as I have with other chips in the past.
These chips however appeared to not be working.
After playing around with them for a bit, I realized that if I plugged the 16mhz crystal into the xtal ports, the blink script was working... however if the 2pcs- 18-22pf caps are connected to the crystal, and ground as they should be, the chips stop blinking and I can not program it or bootload it.
If i pull the crystal, the chip stops blinking. If I put the crystal back in, with no caps, the chip will blink again. Basicly it works without the caps, but not with them.
If I hook it all up with just the crystal .... I can load a bootloader and program the chips using my uno as an isp.
I have tried programming and bootloading them with the correct setup (having the capacitors installed along with the crystal) and I get the dreaded YIKES Invalid device error from avrdude every time. Pop the crystal in without the capacitors and I can communicate with them again.
Is it possible that these chips were bootloaded with just a crystal and somehow the fuses are set wrong?
If so, can I clear them out and program them correctly?
Is my oscillator even capable of generating 16mhz freq without being grounded? (seriously).
This has been driving me bonkers. Any insight would be appreciated. Thanks in advance.