diff --git a/extruder/arduino.h b/extruder/arduino.h
index 476ba1b..b8d1a06 100644
--- a/extruder/arduino.h
+++ b/extruder/arduino.h
@@ -57,6 +57,10 @@
 	#include	"arduino_1280.h"
 #endif	/* __AVR_ATmega1280__ */
 
+#if defined (__AVR_ATmega2560__)
+	#include    "arduino_1280.h" //2560 has the same pins and ports so we can reuse the 1280 file.
+#endif
+
 #ifndef	DIO0_PIN
 #error pins for this chip not defined in arduino.h! If you write an appropriate pin definition and have this firmware work on your chip, please tell us via the forum thread
 #endif
diff --git a/extruder/debug.h b/extruder/debug.h
index 08f0321..e96e268 100644
--- a/extruder/debug.h
+++ b/extruder/debug.h
@@ -3,12 +3,18 @@
 
 #include	<stdint.h>
 
-// by setting these to zero, the compiler should optimise the relevant code out
-#define		DEBUG_PID				0
-#define		DEBUG_DDA				0
-#define		DEBUG_POSITION	0
+#ifdef	DEBUG
+	#define		DEBUG_PID				1
+	#define		DEBUG_DDA				2
+	#define		DEBUG_POSITION	4
+#else
+	// by setting these to zero, the compiler should optimise the relevant code out
+	#define		DEBUG_PID				0
+	#define		DEBUG_DDA				0
+	#define		DEBUG_POSITION	0
+#endif
 
-#define		DEBUG_ECHO			0
+#define		DEBUG_ECHO			128
 
 extern volatile uint8_t	debug_flags;
 
diff --git a/extruder/heater.c b/extruder/heater.c
index 8779dc1..ea79dc5 100644
--- a/extruder/heater.c
+++ b/extruder/heater.c
@@ -6,10 +6,12 @@
 
 #include	"arduino.h"
 #include	"debug.h"
-#ifndef	EXTRUDER
-#include	"sersendf.h"
-#endif
 #include	"temp.h"
+#include	"crc.h"
+
+#ifndef	EXTRUDER
+	#include	"sersendf.h"
+#endif
 
 typedef struct {
 	volatile uint8_t *heater_port;
@@ -59,6 +61,7 @@ typedef struct {
 	int32_t		EE_i_factor;
 	int32_t		EE_d_factor;
 	int16_t		EE_i_limit;
+	uint16_t	crc;
 } EE_factor;
 
 EE_factor EEMEM EE_factors[NUM_HEATERS];
@@ -101,7 +104,8 @@ void heater_init() {
 			heaters_pid[i].d_factor = eeprom_read_dword((uint32_t *) &EE_factors[i].EE_d_factor);
 			heaters_pid[i].i_limit = eeprom_read_word((uint16_t *) &EE_factors[i].EE_i_limit);
 
-			if ((heaters_pid[i].p_factor == 0) && (heaters_pid[i].i_factor == 0) && (heaters_pid[i].d_factor == 0) && (heaters_pid[i].i_limit == 0)) {
+// 			if ((heaters_pid[i].p_factor == 0) && (heaters_pid[i].i_factor == 0) && (heaters_pid[i].d_factor == 0) && (heaters_pid[i].i_limit == 0)) {
+			if (crc_block(&heaters_pid[i].p_factor, 14) != eeprom_read_word((uint16_t *) &EE_factors[i].crc)) {
 				heaters_pid[i].p_factor = DEFAULT_P;
 				heaters_pid[i].i_factor = DEFAULT_I;
 				heaters_pid[i].d_factor = DEFAULT_D;
@@ -119,6 +123,7 @@ void heater_save_settings() {
 			eeprom_write_dword((uint32_t *) &EE_factors[i].EE_i_factor, heaters_pid[i].i_factor);
 			eeprom_write_dword((uint32_t *) &EE_factors[i].EE_d_factor, heaters_pid[i].d_factor);
 			eeprom_write_word((uint16_t *) &EE_factors[i].EE_i_limit, heaters_pid[i].i_limit);
+			eeprom_write_word((uint16_t *) &EE_factors[i].crc, crc_block(&heaters_pid[i].p_factor, 14));
 		}
 	#endif /* BANG_BANG */
 }
@@ -178,9 +183,9 @@ void heater_tick(heater_t h, temp_sensor_t t, uint16_t current_temp, uint16_t ta
 		#endif
 	#else
 		if (current_temp >= target_temp)
-			pid_output = BANG_BANG_ON;
-		else
 			pid_output = BANG_BANG_OFF;
+		else
+			pid_output = BANG_BANG_ON;
 	#endif
 	
 	#ifdef	HEATER_SANITY_CHECK
@@ -308,3 +313,9 @@ void pid_set_i_limit(heater_t index, int32_t i_limit) {
 		heaters_pid[index].i_limit = i_limit;
 	#endif /* BANG_BANG */
 }
+
+#ifndef	EXTRUDER
+void heater_print(uint16_t i) {
+	sersendf_P(PSTR("P:%ld I:%ld D:%ld Ilim:%u crc:%u "), heaters_pid[i].p_factor, heaters_pid[i].i_factor, heaters_pid[i].d_factor, heaters_pid[i].i_limit, crc_block(&heaters_pid[i].p_factor, 14));
+}
+#endif
diff --git a/extruder/heater.h b/extruder/heater.h
index edd3d23..58c4129 100644
--- a/extruder/heater.h
+++ b/extruder/heater.h
@@ -31,4 +31,6 @@ void pid_set_i(heater_t index, int32_t i);
 void pid_set_d(heater_t index, int32_t d);
 void pid_set_i_limit(heater_t index, int32_t i_limit);
 
+void heater_print(uint16_t i);
+
 #endif	/* _HEATER_H */
diff --git a/extruder/temp.c b/extruder/temp.c
index e1d13a5..b0159f5 100644
--- a/extruder/temp.c
+++ b/extruder/temp.c
@@ -15,24 +15,15 @@
 	#include	"intercom.h"
 #endif
 
-typedef enum {
-	TT_THERMISTOR,
-	TT_MAX6675,
-	TT_AD595,
-	TT_PT100,
-	TT_INTERCOM,
-	TT_DUMMY,
-} temp_types;
-
 typedef enum {
 	PRESENT,
 	TCOPEN
 } temp_flags_enum;
 
 typedef struct {
-	uint8_t temp_type;
-	uint8_t temp_pin;
-	uint8_t heater_index;
+	temp_type_t temp_type;
+	uint8_t     temp_pin;
+	heater_t    heater;
 } temp_sensor_definition_t;
 
 #undef DEFINE_TEMP_SENSOR
@@ -95,6 +86,9 @@ void temp_init() {
 				send_temperature(0, 0);
 				break;
 		#endif
+
+			default: /* prevent compiler warning */
+				break;
 		}
 	}
 }
@@ -241,8 +235,6 @@ void temp_sensor_tick() {
 				case TT_INTERCOM:
 					temp = read_temperature(temp_sensors[i].temp_pin);
 
-					start_send();
-
 					temp_sensors_runtime[i].next_read_time = 0;
 
 					break;
@@ -261,6 +253,9 @@ void temp_sensor_tick() {
 
 					break;
 				#endif	/* TEMP_DUMMY */
+
+				default: /* prevent compiler warning */
+					break;
 			}
 			temp_sensors_runtime[i].last_read_temp = temp;
 			
@@ -272,8 +267,8 @@ void temp_sensor_tick() {
 				temp_sensors_runtime[i].temp_residency = 0;
 			}
 			
-			if (temp_sensors[i].heater_index < NUM_HEATERS) {
-				heater_tick(temp_sensors[i].heater_index, i, temp_sensors_runtime[i].last_read_temp, temp_sensors_runtime[i].target_temp);
+			if (temp_sensors[i].heater < NUM_HEATERS) {
+				heater_tick(temp_sensors[i].heater, i, temp_sensors_runtime[i].last_read_temp, temp_sensors_runtime[i].target_temp);
 			}
 		}
 	}
diff --git a/heater.c b/heater.c
index 427c599..ea79dc5 100644
--- a/heater.c
+++ b/heater.c
@@ -314,6 +314,8 @@ void pid_set_i_limit(heater_t index, int32_t i_limit) {
 	#endif /* BANG_BANG */
 }
 
+#ifndef	EXTRUDER
 void heater_print(uint16_t i) {
 	sersendf_P(PSTR("P:%ld I:%ld D:%ld Ilim:%u crc:%u "), heaters_pid[i].p_factor, heaters_pid[i].i_factor, heaters_pid[i].d_factor, heaters_pid[i].i_limit, crc_block(&heaters_pid[i].p_factor, 14));
 }
+#endif