Graylord:
what was supposed to happen. Instead of rapidly blinking when receiving power, it steadily bliinks on, then off every second or so, and any attempts to upload any sketches result in a 0x1b timeout.What does the blinking mean?
After doing a burn bootloader using that "breadboard" hardware package, when I power the board there are some rapid blink sequences, then the LED continues blinking with an off time of about 1 second and an on time about 0.1 second. Is that what you're seeing?
Graylord:
any attempts to upload any sketches result in a 0x1b timeout.
I also couldn't upload to my board after burning that bootloader, which is strange because I remember using it years ago. I tried it with MiniCore's ATmega328P @ 8 MHz internal:
and can upload with no problem.
They both use the same fuse settings for the clock configuration so I can only suspect the bootloader used by the "breadboard" hardware package. Try MiniCore (remember to select Tools > Clock > 8 MHz Internal) to see if that resolves the issue.
Graylord:
I'm using the breadboard1.6 hardware config, as that seems to be the latest one, at least according to the documention. Despite using the 1.8.5 IDE. Is there a later one hidden somewhere?
No, but there has not been any breaking changes to the hardware package specification since 1.6.x (as there was between 1.0.x and 1.6.x) so theoretically that package should be fine for 1.8.5.
Graylord:
This documentation: https://www.arduino.cc/en/Tutorial/ArduinoISP
also claims you may have to fix a bit in the code depending on your arduino version. But there's no delay function in the heartbeat code?
I think that is now this line:
if ((now - last_time) < 40)
which you would change to:
if ((now - last_time) < 20)
but that is "Note for Arduino 1.0" and you're using Arduino IDE 1.8.5 so you don't need to worry about it.