Otherwise, we're waiting 1s on pretty much any call to the display. If
the display gets disconnected at the start of the `update_display()`
function, that can mean quite the delay.
It's possible that this delay triggers a watchdog timer that blinks the
LEDs, but there doesn't appear to be any watchdog timer configured.
The fault handlers blink different LEDs depending on the kind of fault:
HardFault -> All
MemManage -> Left of display
BusFault -> Right of display
UsageFault -> Left and right of display
Additionally, they dump information about the fault to the flash and
Serial (if connected). The information dumped to the flash can later be
retrieved via Serial by sending a 'd'.
jvblanck
jazzpi