Change ARCH and MCU settings to match chip signature

Makefile

@@ -9,10 +9,10 @@
 # ==============================================================================
 
 VERBOSE   := false
-ARCH      := m1284p
+ARCH      := m1284
 #FREQ     := 18432000UL
 FREQ      := 8000000UL
-MCU       := atmega1284p
+MCU       := atmega1284
 ASP       := usbasp
 CC        := avr-gcc
 LD        := $(CC)

src/bus/pwm.c

@@ -59,7 +59,6 @@ int PWM_Init(void)
 	// Register, these bits control the counting sequence of
 	// the counter, the source for maximum (TOP) counter
 	// value, and what type of waveform generation to be used.
-	// See page 115 of the ATMega32A data sheet for all modes.
 
 	// Mode  WGM13 WGM12 WGM11 WGM10  Timer Mode   TOP
 	// 14    1     1     1     0      Fast PWM     ICR1

src/main.c

@@ -12,7 +12,6 @@
 // TODO: Config header for chip specifics like EEPROM size.
 // TODO: Check thermistor conversion results /w thermometer.
 // TODO: Implement primary state machine for update loop.
-// TODO: Migrate to ATMega 1284P-PU for 2nd 16-bit timer.
 // TODO: Use 18.432MHz quarz crystal, burn required fuses.
 // TODO: Implement optional CRC8 sensor measurement check.
 // TODO: Proper error handling and recovery (after testing).
@@ -108,19 +107,9 @@ static int Init(void)
 	// MOS_Enable(MOS01);   // Peltier
 	// MOS_Disable(MOS02);  // Heating
 
-	// Only FAN01 and FAN02 are receiving the correct
-	// frequency (25 KHz) right now. The 16-bit timer on
-	// the ATMega32A has two outputs so it would require
-	// software PWM to have a variable frequency on PD7.
-
-	// A simple implementation will take up around 30-50
-	// percent of CPU time. Faster approaches are quite
-	// complicated so it might be worth it to switch to
-	// something like an ATmega328PB.
-
 	PWM_SetValue(FAN01, 50);  // Fan Peltier Hot side
 	PWM_SetValue(FAN02, 50);  // Fan Peltier Cold Side
-	// PWM_SetValue(FAN03, 20);  // Fan Heating
+	PWM_SetValue(FAN03, 50);  // Fan Heating
 
 	// The I2C_SetChannel command changes the channel
 	// setting of the PCA9546 I2C multiplexer. Any