Move PWM and MOSFET implementations into separate module files

src/bus/pwm.h

@@ -0,0 +1,19 @@
+#ifndef MAD_BUS_PWM_H
+#define MAD_BUS_PWM_H
+
+#include <avr/io.h>
+
+// PWM Devices
+#define FAN01 PD4  // NF-12 Fan Peltier Hot Side Speed
+#define FAN02 PD5  // NF-A8 Fan Peltier Cold Side Speed
+#define FAN03 PD7  // NF-R8 Fan Heating Element Speed
+
+#define PWM_CYCLE_TOP  (F_CPU / 25000) // 25 KHz
+#define FAN01_MIN_DUTY (PWM_CYCLE_TOP * 0.2f)
+#define FAN02_MIN_DUTY (PWM_CYCLE_TOP * 0.2f)
+#define FAN03_MIN_DUTY (PWM_CYCLE_TOP * 0.2f)
+
+int PWM_Init(void);
+void PWM_SetValue(int port, int value);
+
+#endif // MAD_BUS_PWM_H