- Changed all float constants to use f suffix to prevent double conversions
- Removed compile warnings due to HAL_GPIO_* related calls
- Added comms.h with prototypes for functions which were used in main()
- Casts and externs to fix compile warnings in various files.
- Made a bunch of file-local variables static.
- Fixed buzzerFreq/buzzerPattern extern declarations with correct type (uint8_t)
- Since this is C, void func() { } needs to be void func(void) { }, so fixed that in all instances.
These updates follows from @trollcop
