- Implement advanced LED flash support
- Tweak HAL_SPI_TransmitReceive to tolerate a longer SysTick interrupt
- Tune KEYBOARD_BOTDETECT parameters
- L-shift and R-shift are now high-speed alphanumeric keys
It turns out that suspend support on the STM32 USB core is buggy as
heck. Host mode cannot resume after suspend, and device mode cannot
receive resume or send wakeup signalling.
I managed to fake resume support by keeping Downstream and our connected
device running at full power, and simulating a wakeup event to the host
by disconnecting/reconnecting Upstream from the host.