I bought a couple of bootloaded ATMEGA328P-PU chips (Optiboot) and tried them in my Uno board. When I tried to download a sketch to them the TX led blinked faintly, that’s it, and I got the typical stk500 synchronisation message. Put the original chip back in and everything working fine.
I asked the Ebay vendor if the chips should work in an Uno board but they didn’t answer that question, they only said to hook it up to a crystal, etc and a serial connection. Are there different versions of bootloaders, and some won’t work in an Uno (clone) board.
My intention was to just pop the bootloaded AVRs into my Uno board, download the sketch to them then use the AVRs standalone in a circuit.
Is my thinking wrong. I’ve also just seen on Youtube that this could mean the AVRs are not actually bootloaded.
I would have thought the vendor would clearly state if the bootloader was for 8Mhz.
My Google searches led me to some buyers experiences where supposedly bootloaded AVRs actually had no bootloader. I wonder if I had that problem.
I ended up burning the bootloader myself using my Uno clone as an ISP, and putting the ATMEGA328 on a breadboard. Worked great and afterwards I could program sketches onto them using my Uno board.