Got my new RPi 3s. So exciting! Connect to my serial cable, fire up Serial on the Mac, ready to install my normal way, and….garbled garbage.

Turns out some winner in Piland re-used GPIO pins necessary to make serial work for Bluetooth. I guess they figured that no one used serial console?

To fix, you’ll need a monitor & keyboard. First follow the instructions here up through “Update firmware” (rpi-update). Then edit /boot/config.txt and add the line:

    dtoverlay=pi3-disable-bt

Reboot, and your serial console will work again.