I have an Arduino Uno R3 and about 10 Atmega chips, several each of Atmega328-PU and Atmega328p-PU. When attempting to upload a sketch I am getting the error programmer is not responding, like this:
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xb1
I assumed that these chips did not have a bootloader so I went through the process found here https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard to burn a bootloader which was successful. Now when I put the chip in the arduino board the led light starts blinking so I think that means there is a bootloader. But I still cant upload a sketch.
I might have assumed that the board was bad but I have one chip, an Atmega328-PU, that works. All of the other ones result in the above error when attempting to upload a sketch. This is the only chip that works and the one that I used to burn the bootloaders on the other chips.
There is only one serial port in device manager and it disappears when the arduino board is unplugged. This port is selected in the arduino IDE.
I have Arduino\Genuino Uno selected as the board in the IDE.
I have confirmed that the loopback test described here Loop-Back Test Instructions - Installation & Troubleshooting - Arduino Forum is working.
Is there anything else I should check? I got these chips from two different places and have not even been used before, I would find it hard to believe that they are all bad.