Use external 18.432 MHz crystal oscillator with full swing fuse settings

Makefile

@@ -11,7 +11,7 @@
 VERBOSE   := false
 ARCH      := m1284
 MCU       := atmega1284p
-FREQ      := 8000000UL
+FREQ      := 18432000UL
 ISP       := usbasp
 CC        := avr-gcc
 LD        := $(CC)
@@ -22,7 +22,7 @@ MKDIR     := mkdir -p
 RMR       := rm -rf
 GIT       := git
 
-LFUSE     := 0xC2
+LFUSE     := 0xF7
 HFUSE     := 0x97
 EFUSE     := 0xFF
 LOCK      := 0xFF

docs/TODO.md

@@ -1,6 +1,5 @@
 ## Current Tasks
 
-- Test stability with 18.432 MHz external oscillator.
 - Implement state machine for actual drying operation.
 - Rewrite code documentation with proper structure.
 - Check sensor measurements, conversion results and timer output frequencies.