diff --git a/CMakeLists.txt b/CMakeLists.txt
index c0c2aacd0..4ca1d95be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,7 @@ set(TEST_SOURCES
 	Tests/Example_test.cpp
 	Tests/Timer_test.cpp
 	Tests/AutoDeplete_test.cpp
+	Tests/PrusaStatistics_test.cpp
 	Firmware/Timer.cpp
 	Firmware/AutoDeplete.cpp
 )
diff --git a/Firmware/Marlin.h b/Firmware/Marlin.h
index a44346619..625e079ea 100755
--- a/Firmware/Marlin.h
+++ b/Firmware/Marlin.h
@@ -79,9 +79,9 @@ extern FILE _uartout;
 #define SERIAL_PROTOCOL_F(x,y) (MYSERIAL.print(x,y))
 #define SERIAL_PROTOCOLPGM(x) (serialprintPGM(PSTR(x)))
 #define SERIAL_PROTOCOLRPGM(x) (serialprintPGM((x)))
-#define SERIAL_PROTOCOLLN(x) (MYSERIAL.print(x),MYSERIAL.write('\n'))
-#define SERIAL_PROTOCOLLNPGM(x) (serialprintPGM(PSTR(x)),MYSERIAL.write('\n'))
-#define SERIAL_PROTOCOLLNRPGM(x) (serialprintPGM((x)),MYSERIAL.write('\n'))
+#define SERIAL_PROTOCOLLN(x) (MYSERIAL.println(x)/*,MYSERIAL.write('\n')*/)
+#define SERIAL_PROTOCOLLNPGM(x) (serialprintPGM(PSTR(x)),MYSERIAL.println()/*write('\n')*/)
+#define SERIAL_PROTOCOLLNRPGM(x) (serialprintPGM((x)),MYSERIAL.println()/*write('\n')*/)
 
 
 extern const char errormagic[] PROGMEM;
@@ -111,15 +111,9 @@ void serial_echopair_P(const char *s_P, unsigned long v);
 
 
 //Things to write to serial from Program memory. Saves 400 to 2k of RAM.
-FORCE_INLINE void serialprintPGM(const char *str)
-{
-  char ch=pgm_read_byte(str);
-  while(ch)
-  {
-    MYSERIAL.write(ch);
-    ch=pgm_read_byte(++str);
-  }
-}
+// Making this FORCE_INLINE is not a good idea when running out of FLASH
+// I'd rather skip a few CPU ticks than 5.5KB (!!) of FLASH
+void serialprintPGM(const char *str);
 
 bool is_buffer_empty();
 void get_command();
@@ -403,6 +397,7 @@ extern LongTimer safetyTimer;
 
 #define PRINT_PERCENT_DONE_INIT   0xff
 #define PRINTER_ACTIVE (IS_SD_PRINTING || is_usb_printing || isPrintPaused || (custom_message_type == CustomMsg::TempCal) || saved_printing || (lcd_commands_type == LcdCommands::Layer1Cal) || card.paused || mmu_print_saved)
+
 //! Beware - mcode_in_progress is set as soon as the command gets really processed,
 //! which is not the same as posting the M600 command into the command queue
 //! There can be a considerable lag between posting M600 and its real processing which might result
diff --git a/Firmware/MarlinSerial.h b/Firmware/MarlinSerial.h
index d596708e4..27e722bc0 100644
--- a/Firmware/MarlinSerial.h
+++ b/Firmware/MarlinSerial.h
@@ -96,7 +96,7 @@ class MarlinSerial //: public Stream
     static int read(void);
     static void flush(void);
     
-    static FORCE_INLINE int available(void)
+    static /*FORCE_INLINE*/ int available(void)
     {
       return (unsigned int)(RX_BUFFER_SIZE + rx_buffer.head - rx_buffer.tail) % RX_BUFFER_SIZE;
     }
@@ -184,14 +184,14 @@ class MarlinSerial //: public Stream
     
   public:
     
-    static FORCE_INLINE void write(const char *str)
+    static /*FORCE_INLINE*/ void write(const char *str)
     {
       while (*str)
         write(*str++);
     }
 
 
-    static FORCE_INLINE void write(const uint8_t *buffer, size_t size)
+    static /*FORCE_INLINE*/ void write(const uint8_t *buffer, size_t size)
     {
       while (size--)
         write(*buffer++);
diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index 0e5850b96..35722679b 100755
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -411,6 +411,24 @@ void serial_echopair_P(const char *s_P, double v)
 void serial_echopair_P(const char *s_P, unsigned long v)
     { serialprintPGM(s_P); SERIAL_ECHO(v); }
 
+/*FORCE_INLINE*/ void serialprintPGM(const char *str)
+{
+#if 0
+  char ch=pgm_read_byte(str);
+  while(ch)
+  {
+    MYSERIAL.write(ch);
+    ch=pgm_read_byte(++str);
+  }
+#else
+	// hmm, same size as the above version, the compiler did a good job optimizing the above
+	while( uint8_t ch = pgm_read_byte(str) ){
+	  MYSERIAL.write((char)ch);
+	  ++str;
+	}
+#endif
+}
+
 #ifdef SDSUPPORT
   #include "SdFatUtil.h"
   int freeMemory() { return SdFatUtil::FreeRam(); }
diff --git a/Firmware/ultralcd.cpp b/Firmware/ultralcd.cpp
index 59489b062..ac7539d63 100755
--- a/Firmware/ultralcd.cpp
+++ b/Firmware/ultralcd.cpp
@@ -1065,7 +1065,7 @@ static void lcd_status_screen()
 }
 
 void lcd_commands()
-{	
+{
 	if (lcd_commands_type == LcdCommands::LongPause)
 	{
 		if (!blocks_queued() && !homing_flag)
@@ -1449,9 +1449,9 @@ void lcd_commands()
                     lcd_wizard(WizState::RepeatLay1Cal);
                 }
                 break;
-            }
-        }
-	}
+		}
+			}
+		}
 
 #endif // not SNMM
 
@@ -1966,7 +1966,6 @@ static void lcd_menu_debug()
 static void lcd_menu_temperatures()
 {
 	lcd_timeoutToStatus.stop(); //infinite timeout
-	
 	lcd_home();
 	lcd_printf_P(PSTR(" %S:   %d%c \n" " %S:      %d%c \n"), _i("Nozzle"), (int)current_temperature[0], '\x01', _i("Bed"), (int)current_temperature_bed, '\x01');
 #ifdef AMBIENT_THERMISTOR
@@ -2581,7 +2580,7 @@ void lcd_change_success() {
 }
 
 static void lcd_loading_progress_bar(uint16_t loading_time_ms) { 
-	
+
 	for (uint_least8_t i = 0; i < 20; i++) {
 		lcd_set_cursor(i, 3);
 		lcd_print(".");
@@ -2830,7 +2829,6 @@ void lcd_menu_statistics()
 			"%S:\n"
 			"%2dh %02dm %02ds"
 		),_i("Filament used"), _met, _i("Print time"), _h, _m, _s);
-		
 		menu_back_if_clicked_fb();
 	}
 	else
@@ -2853,7 +2851,6 @@ void lcd_menu_statistics()
 			"%S:\n"
 			"%7ldd :%2hhdh :%02hhdm"
 		), _i("Total filament"), _filament_m, _i("Total print time"), _days, _hours, _minutes);
-		
 		KEEPALIVE_STATE(PAUSED_FOR_USER);
 		while (!lcd_clicked())
 		{
@@ -3956,6 +3953,20 @@ void lcd_menu_show_sensors_state()                // NOT static due to using ins
 	}
 }
 
+void prusa_statistics_err(char c){
+	SERIAL_ECHO("{[ERR:");
+	SERIAL_ECHO(c);
+	SERIAL_ECHO(']');
+	prusa_stat_farm_number();
+}
+
+static void prusa_statistics_case0(uint8_t statnr){
+	SERIAL_ECHO("{");
+	prusa_stat_printerstatus(statnr);
+	prusa_stat_farm_number();
+	prusa_stat_printinfo();
+}
+
 void prusa_statistics(int _message, uint8_t _fil_nr) {
 #ifdef DEBUG_DISABLE_PRUSA_STATISTICS
 	return;
@@ -3965,31 +3976,16 @@ void prusa_statistics(int _message, uint8_t _fil_nr) {
 
 	case 0: // default message
 		if (busy_state == PAUSED_FOR_USER) 
-		{
-			SERIAL_ECHO("{");
-			prusa_stat_printerstatus(15);
-			prusa_stat_farm_number();
-			prusa_stat_printinfo();
-			SERIAL_ECHOLN("}");
-			status_number = 15;
+		{   
+			prusa_statistics_case0(15);
 		}
 		else if (isPrintPaused || card.paused) 
 		{
-			SERIAL_ECHO("{");
-			prusa_stat_printerstatus(14);
-			prusa_stat_farm_number();
-			prusa_stat_printinfo();
-			SERIAL_ECHOLN("}");
-			status_number = 14;
+			prusa_statistics_case0(14);
 		}
 		else if (IS_SD_PRINTING || loading_flag)
 		{
-			SERIAL_ECHO("{");
-			prusa_stat_printerstatus(4);
-			prusa_stat_farm_number();
-			prusa_stat_printinfo();
-			SERIAL_ECHOLN("}");
-			status_number = 4;
+			prusa_statistics_case0(4);
 		}
 		else
 		{
@@ -3997,82 +3993,76 @@ void prusa_statistics(int _message, uint8_t _fil_nr) {
 			prusa_stat_printerstatus(1);
 			prusa_stat_farm_number();
 			prusa_stat_diameter();
-			SERIAL_ECHOLN("}");
 			status_number = 1;
 		}
 		break;
 
 	case 1:		// 1 heating
 		farm_status = 2;
-		SERIAL_ECHO("{");
+		SERIAL_ECHO('{');
 		prusa_stat_printerstatus(2);
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		status_number = 2;
 		farm_timer = 1;
 		break;
 
 	case 2:		// heating done
 		farm_status = 3;
-		SERIAL_ECHO("{");
+		SERIAL_ECHO('{');
 		prusa_stat_printerstatus(3);
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
+		SERIAL_ECHOLN('}');
 		status_number = 3;
 		farm_timer = 1;
 
 		if (IS_SD_PRINTING || loading_flag)
 		{
 			farm_status = 4;
-			SERIAL_ECHO("{");
+			SERIAL_ECHO('{');
 			prusa_stat_printerstatus(4);
 			prusa_stat_farm_number();
-			SERIAL_ECHOLN("}");
 			status_number = 4;
 		}
 		else
 		{
-			SERIAL_ECHO("{");
+			SERIAL_ECHO('{');
 			prusa_stat_printerstatus(3);
 			prusa_stat_farm_number();
-			SERIAL_ECHOLN("}");
 			status_number = 3;
 		}
 		farm_timer = 1;
 		break;
 
 	case 3:		// filament change
-
+		// must do a return here to prevent doing SERIAL_ECHOLN("}") at the very end of this function
+		// saved a considerable amount of FLASH
+		return;
 		break;
 	case 4:		// print succesfull
 		SERIAL_ECHO("{[RES:1][FIL:");
 		MYSERIAL.print(int(_fil_nr));
-		SERIAL_ECHO("]");
+		SERIAL_ECHO(']');
 		prusa_stat_printerstatus(status_number);
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		farm_timer = 2;
 		break;
 	case 5:		// print not succesfull
 		SERIAL_ECHO("{[RES:0][FIL:");
 		MYSERIAL.print(int(_fil_nr));
-		SERIAL_ECHO("]");
+		SERIAL_ECHO(']');
 		prusa_stat_printerstatus(status_number);
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		farm_timer = 2;
 		break;
 	case 6:		// print done
 		SERIAL_ECHO("{[PRN:8]");
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		status_number = 8;
 		farm_timer = 2;
 		break;
 	case 7:		// print done - stopped
 		SERIAL_ECHO("{[PRN:9]");
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		status_number = 9;
 		farm_timer = 2;
 		break;
@@ -4080,49 +4070,38 @@ void prusa_statistics(int _message, uint8_t _fil_nr) {
 		SERIAL_ECHO("{[PRN:0][PFN:");
 		status_number = 0;
 		SERIAL_ECHO(farm_no);
-		SERIAL_ECHOLN("]}");
+		SERIAL_ECHO(']');
 		farm_timer = 2;
 		break;
 	case 20:		// echo farm no
-		SERIAL_ECHO("{");
+		SERIAL_ECHO('{');
 		prusa_stat_printerstatus(status_number);
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		farm_timer = 4;
 		break;
 	case 21: // temperatures
-		SERIAL_ECHO("{");
+		SERIAL_ECHO('{');
 		prusa_stat_temperatures();
 		prusa_stat_farm_number();
 		prusa_stat_printerstatus(status_number);
-		SERIAL_ECHOLN("}");
 		break;
     case 22: // waiting for filament change
         SERIAL_ECHO("{[PRN:5]");
 		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
 		status_number = 5;
         break;
 	
 	case 90: // Error - Thermal Runaway
-		SERIAL_ECHO("{[ERR:1]");
-		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
+		prusa_statistics_err('1');
 		break;
 	case 91: // Error - Thermal Runaway Preheat
-		SERIAL_ECHO("{[ERR:2]");
-		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
+		prusa_statistics_err('2');
 		break;
 	case 92: // Error - Min temp
-		SERIAL_ECHO("{[ERR:3]");
-		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
+		prusa_statistics_err('3');
 		break;
 	case 93: // Error - Max temp
-		SERIAL_ECHO("{[ERR:4]");
-		prusa_stat_farm_number();
-		SERIAL_ECHOLN("}");
+		prusa_statistics_err('4');
 		break;
 
     case 99:		// heartbeat
@@ -4130,11 +4109,11 @@ void prusa_statistics(int _message, uint8_t _fil_nr) {
         prusa_stat_temperatures();
 		SERIAL_ECHO("[PFN:");
 		SERIAL_ECHO(farm_no);
-		SERIAL_ECHO("]");
-        SERIAL_ECHOLN("}");
+		SERIAL_ECHO(']');
             
         break;
 	}
+	SERIAL_ECHOLN('}');	
 
 }
 
@@ -4142,19 +4121,19 @@ static void prusa_stat_printerstatus(int _status)
 {
 	SERIAL_ECHO("[PRN:");
 	SERIAL_ECHO(_status);
-	SERIAL_ECHO("]");
+	SERIAL_ECHO(']');
 }
 
 static void prusa_stat_farm_number() {
 	SERIAL_ECHO("[PFN:");
 	SERIAL_ECHO(farm_no);
-	SERIAL_ECHO("]");
+	SERIAL_ECHO(']');
 }
 
 static void prusa_stat_diameter() {
 	SERIAL_ECHO("[DIA:");
 	SERIAL_ECHO(eeprom_read_word((uint16_t*)EEPROM_NOZZLE_DIAMETER_uM));
-	SERIAL_ECHO("]");
+	SERIAL_ECHO(']');
 }
 
 static void prusa_stat_temperatures()
@@ -4167,7 +4146,7 @@ static void prusa_stat_temperatures()
 	SERIAL_ECHO(current_temperature[0]);
 	SERIAL_ECHO("][ATB:");
 	SERIAL_ECHO(current_temperature_bed);
-	SERIAL_ECHO("]");
+	SERIAL_ECHO(']');
 }
 
 static void prusa_stat_printinfo()
@@ -4191,7 +4170,7 @@ static void prusa_stat_printinfo()
 	}
 	SERIAL_ECHO("][FWR:");
 	SERIAL_ECHO(FW_VERSION);
-	SERIAL_ECHO("]");
+	SERIAL_ECHO(']');
      prusa_stat_diameter();
 }
 
@@ -6754,7 +6733,7 @@ void stepper_timer_overflow() {
 static void lcd_colorprint_change() {
 	
 	enquecommand_P(PSTR("M600"));
-	
+
 	custom_message_type = CustomMsg::FilamentLoading; //just print status message
 	lcd_setstatuspgm(_T(MSG_FINISHING_MOVEMENTS));
 	lcd_return_to_status();
@@ -8278,7 +8257,7 @@ static void menu_action_sdfile(const char* filename)
 
   //we are storing just first 8 characters of 8.3 filename assuming that extension is always ".gco"
   for (uint_least8_t i = 0; i < 8; i++) {
-	  if (strcmp((cmd + i + 4), end) == 0) { 
+	  if (strcmp((cmd + i + 4), end) == 0) {
 		  //filename is shorter then 8.3, store '\0' character on position where ".gco" string was found to terminate stored string properly
  		  eeprom_write_byte((uint8_t*)EEPROM_FILENAME + i, '\0');
 		  break;
diff --git a/README.md b/README.md
index 765204a50..c44983ba7 100644
--- a/README.md
+++ b/README.md
@@ -14,11 +14,24 @@
 
 # Build
 ## Linux
-Run shell script build.sh to build for MK3 and flash with Slic3er.  
-If you have a different printer model, follow step [2.b](#2b) from Windows build first.  
-If you wish to flash from Arduino, follow step [2.c](#2c) from Windows build first.  
 
-The script downloads Arduino with our modifications and Rambo board support installed, unpacks it into folder PF-build-env-\<version\> on the same level, as your Prusa-Firmware folder is located, builds firmware for MK3 using that Arduino in Prusa-Firmware-build folder on the same level as Prusa-Firmware, runs secondary language support scripts. Firmware with secondary language support is generated in lang subfolder. Use firmware.hex for MK3 variant. Use firmware_\<lang\>.hex for other printers. Don't forget to follow step [2.b](#2b) first for non-MK3 printers.
+1. Clone this repository and checkout the correct branch for your desired release version.
+
+2. Set your printer model. 
+   - For MK3 --> skip to step 3. 
+   - If you have a different printer model, follow step [2.b](#2b) from Windows build
+   
+3. Run `sudo ./build.sh`
+   - Output hex file is at `"PrusaFirmware/lang/firmware.hex"` . In the same folder you can hex files for other languages as well.
+
+4. Connect your printer and flash with PrusaSlicer ( Configuration --> Flash printer firmware ) or Slic3r PE.
+   - If you wish to flash from Arduino, follow step [2.c](#2c) from Windows build first.
+
+
+_Notes:_
+
+The script downloads Arduino with our modifications and Rambo board support installed, unpacks it into folder `PF-build-env-\<version\>` on the same level, as your Prusa-Firmware folder is located, builds firmware for MK3 using that Arduino in Prusa-Firmware-build folder on the same level as Prusa-Firmware, runs secondary language support scripts. Firmware with secondary language support is generated in lang subfolder. Use firmware.hex for MK3 variant. Use `firmware_\<lang\>.hex` for other printers. Don't forget to follow step [2.b](#2b) first for non-MK3 printers.
+
 ## Windows
 ### Using Arduino
 note: Multi language build is not supported.
diff --git a/Tests/PrusaStatistics_test.cpp b/Tests/PrusaStatistics_test.cpp
new file mode 100644
index 000000000..587a3fb0f
--- /dev/null
+++ b/Tests/PrusaStatistics_test.cpp
@@ -0,0 +1,793 @@
+/**
+ * @file
+ * @author Marek Kuhn
+ */
+
+// For now the functions are just COPIED (lots of depencendies in ultralcd.h)
+
+#include "catch.hpp"
+#include <iostream>
+
+
+std::string itostr3(int i){
+	return std::to_string(i);
+}
+
+std::string eeprom_read_word(uint16_t* /*i*/){
+	return "eeprom_read";
+}
+
+int _millis(){return 10000;}
+
+static int farm_no;
+static int busy_state;
+static int PAUSED_FOR_USER;
+static int status_number;
+static int total_filament_used;
+static int feedmultiply;
+static int longFilenameOLD;
+static int starttime;
+static int isPrintPaused;
+static int IS_SD_PRINTING;
+static int farm_status;
+static int farm_timer;
+static int loading_flag;
+
+static int target_temperature[1];
+static int current_temperature[1];
+static int target_temperature_bed;
+static int current_temperature_bed;
+
+static uint16_t nozzle_diameter;
+static uint16_t* EEPROM_NOZZLE_DIAMETER_uM;
+
+static std::string FW_VERSION;
+
+struct Card {
+	int paused = 0;
+	int percentDone(){ return 50; }
+};
+
+static Card card;
+
+void setup_mockups(){
+	farm_no = 0;
+
+	busy_state = 0;
+	status_number = 0;
+	PAUSED_FOR_USER = 0;
+
+	total_filament_used = 0;
+	feedmultiply = 0;
+	longFilenameOLD = 0;
+	starttime = 0;
+
+	FW_VERSION = "3.8.0";
+
+	isPrintPaused = 0;
+	IS_SD_PRINTING = 0;
+	farm_status = 0;
+	farm_timer = 1;
+	loading_flag = 0;
+
+	target_temperature[0] = {215};
+	current_temperature[0] = {204};
+	target_temperature_bed = 60;
+	current_temperature_bed = 55;
+
+	nozzle_diameter = 400;
+	EEPROM_NOZZLE_DIAMETER_uM = &nozzle_diameter;
+
+}
+
+
+// Copy of pre 3.8 version set of functions
+namespace old_code
+{
+
+// Mocking Serial line
+static std::string SERIAL_BUFFER = "";
+
+void SERIAL_ECHO(std::string s){
+	SERIAL_BUFFER += s; 
+}
+
+void SERIAL_ECHO(int i){
+	SERIAL_BUFFER += std::to_string(i);
+}
+
+void SERIAL_ECHO(char c){
+	SERIAL_BUFFER += char(c);
+}
+
+void SERIAL_ECHOLN(std::string s){
+	SERIAL_BUFFER += s + "\n";
+}
+
+void SERIAL_ECHOLN(char c){
+	SERIAL_BUFFER += char(c);
+}
+
+void SERIAL_RESET(){
+	SERIAL_BUFFER.clear();
+}
+
+struct MySerial {
+	void print(int i){
+		SERIAL_ECHO(i);
+	}
+	void println(){
+		SERIAL_ECHO("\n");
+	}
+};
+
+static MySerial MYSERIAL;
+
+static void prusa_stat_printerstatus(int _status)
+{
+	SERIAL_ECHO("[PRN:");
+	SERIAL_ECHO(_status);
+	SERIAL_ECHO("]");
+}
+
+static void prusa_stat_farm_number() {
+	SERIAL_ECHO("[PFN:");
+	SERIAL_ECHO(farm_no);
+	SERIAL_ECHO("]");
+}
+
+static void prusa_stat_diameter() {
+	SERIAL_ECHO("[DIA:");
+	SERIAL_ECHO(eeprom_read_word((uint16_t*)EEPROM_NOZZLE_DIAMETER_uM));
+	SERIAL_ECHO("]");
+}
+
+static void prusa_stat_temperatures()
+{
+	SERIAL_ECHO("[ST0:");
+	SERIAL_ECHO(target_temperature[0]);
+	SERIAL_ECHO("][STB:");
+	SERIAL_ECHO(target_temperature_bed);
+	SERIAL_ECHO("][AT0:");
+	SERIAL_ECHO(current_temperature[0]);
+	SERIAL_ECHO("][ATB:");
+	SERIAL_ECHO(current_temperature_bed);
+	SERIAL_ECHO("]");
+}
+
+static void prusa_stat_printinfo()
+{
+	SERIAL_ECHO("[TFU:");
+	SERIAL_ECHO(total_filament_used);
+	SERIAL_ECHO("][PCD:");
+	SERIAL_ECHO(itostr3(card.percentDone()));
+	SERIAL_ECHO("][FEM:");
+	SERIAL_ECHO(itostr3(feedmultiply));
+	SERIAL_ECHO("][FNM:");
+	SERIAL_ECHO(longFilenameOLD);
+	SERIAL_ECHO("][TIM:");
+	if (starttime != 0)
+	{
+		SERIAL_ECHO(_millis() / 1000 - starttime / 1000);
+	}
+	else
+	{
+		SERIAL_ECHO(0);
+	}
+	SERIAL_ECHO("][FWR:");
+	SERIAL_ECHO(FW_VERSION);
+	SERIAL_ECHO("]");
+     prusa_stat_diameter();
+}
+
+void prusa_statistics(int _message, uint8_t _fil_nr) {
+#ifdef DEBUG_DISABLE_PRUSA_STATISTICS
+	return;
+#endif //DEBUG_DISABLE_PRUSA_STATISTICS
+	switch (_message)
+	{
+
+	case 0: // default message
+		if (busy_state == PAUSED_FOR_USER) 
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(15);
+			prusa_stat_farm_number();
+			prusa_stat_printinfo();
+			SERIAL_ECHOLN("}");
+			status_number = 15;
+		}
+		else if (isPrintPaused || card.paused) 
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(14);
+			prusa_stat_farm_number();
+			prusa_stat_printinfo();
+			SERIAL_ECHOLN("}");
+			status_number = 14;
+		}
+		else if (IS_SD_PRINTING || loading_flag)
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(4);
+			prusa_stat_farm_number();
+			prusa_stat_printinfo();
+			SERIAL_ECHOLN("}");
+			status_number = 4;
+		}
+		else
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(1);
+			prusa_stat_farm_number();
+			prusa_stat_diameter();
+			SERIAL_ECHOLN("}");
+			status_number = 1;
+		}
+		break;
+
+	case 1:		// 1 heating
+		farm_status = 2;
+		SERIAL_ECHO("{");
+		prusa_stat_printerstatus(2);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		status_number = 2;
+		farm_timer = 1;
+		break;
+
+	case 2:		// heating done
+		farm_status = 3;
+		SERIAL_ECHO("{");
+		prusa_stat_printerstatus(3);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		status_number = 3;
+		farm_timer = 1;
+
+		if (IS_SD_PRINTING || loading_flag)
+		{
+			farm_status = 4;
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(4);
+			prusa_stat_farm_number();
+			SERIAL_ECHOLN("}");
+			status_number = 4;
+		}
+		else
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(3);
+			prusa_stat_farm_number();
+			SERIAL_ECHOLN("}");
+			status_number = 3;
+		}
+		farm_timer = 1;
+		break;
+
+	case 3:		// filament change
+
+		break;
+	case 4:		// print succesfull
+		SERIAL_ECHO("{[RES:1][FIL:");
+		MYSERIAL.print(int(_fil_nr));
+		SERIAL_ECHO("]");
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		farm_timer = 2;
+		break;
+	case 5:		// print not succesfull
+		SERIAL_ECHO("{[RES:0][FIL:");
+		MYSERIAL.print(int(_fil_nr));
+		SERIAL_ECHO("]");
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		farm_timer = 2;
+		break;
+	case 6:		// print done
+		SERIAL_ECHO("{[PRN:8]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		status_number = 8;
+		farm_timer = 2;
+		break;
+	case 7:		// print done - stopped
+		SERIAL_ECHO("{[PRN:9]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		status_number = 9;
+		farm_timer = 2;
+		break;
+	case 8:		// printer started
+		SERIAL_ECHO("{[PRN:0][PFN:");
+		status_number = 0;
+		SERIAL_ECHO(farm_no);
+		SERIAL_ECHOLN("]}");
+		farm_timer = 2;
+		break;
+	case 20:		// echo farm no
+		SERIAL_ECHO("{");
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		farm_timer = 4;
+		break;
+	case 21: // temperatures
+		SERIAL_ECHO("{");
+		prusa_stat_temperatures();
+		prusa_stat_farm_number();
+		prusa_stat_printerstatus(status_number);
+		SERIAL_ECHOLN("}");
+		break;
+    case 22: // waiting for filament change
+        SERIAL_ECHO("{[PRN:5]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		status_number = 5;
+        break;
+	
+	case 90: // Error - Thermal Runaway
+		SERIAL_ECHO("{[ERR:1]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		break;
+	case 91: // Error - Thermal Runaway Preheat
+		SERIAL_ECHO("{[ERR:2]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		break;
+	case 92: // Error - Min temp
+		SERIAL_ECHO("{[ERR:3]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		break;
+	case 93: // Error - Max temp
+		SERIAL_ECHO("{[ERR:4]");
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN("}");
+		break;
+
+    case 99:		// heartbeat
+        SERIAL_ECHO("{[PRN:99]");
+        prusa_stat_temperatures();
+		SERIAL_ECHO("[PFN:");
+		SERIAL_ECHO(farm_no);
+		SERIAL_ECHO("]");
+        SERIAL_ECHOLN("}");
+            
+        break;
+	}
+
+}
+}
+
+// Copy of 3.8 version of functions
+namespace new_code
+{
+
+// Mocking Serial line
+static std::string SERIAL_BUFFER = "";
+
+void SERIAL_ECHO(std::string s){
+	SERIAL_BUFFER += s; 
+}
+
+void SERIAL_ECHO(int i){
+	SERIAL_BUFFER += std::to_string(i);
+}
+
+void SERIAL_ECHO(char c){
+	SERIAL_BUFFER += char(c);
+}
+
+void SERIAL_ECHOLN(std::string s){
+	SERIAL_BUFFER += s + "\n";
+}
+
+void SERIAL_ECHOLN(char c){
+	SERIAL_BUFFER += char(c);
+	SERIAL_BUFFER += "\n";
+}
+
+void SERIAL_RESET(){
+	SERIAL_BUFFER.clear();
+}
+
+struct MySerial {
+	void print(int i){
+		SERIAL_ECHO(i);
+	}
+	void println(){
+		SERIAL_ECHO("\n");
+	}
+};
+
+static MySerial MYSERIAL;
+
+static void prusa_stat_printerstatus(int _status)
+{
+	SERIAL_ECHO("[PRN:");
+	SERIAL_ECHO(_status);
+	SERIAL_ECHO(']');
+}
+
+static void prusa_stat_farm_number() {
+	SERIAL_ECHO("[PFN:");
+	SERIAL_ECHO(farm_no);
+	SERIAL_ECHO(']');
+}
+
+static void prusa_stat_diameter() {
+	SERIAL_ECHO("[DIA:");
+	SERIAL_ECHO(eeprom_read_word((uint16_t*)EEPROM_NOZZLE_DIAMETER_uM));
+	SERIAL_ECHO(']');
+}
+
+static void prusa_stat_temperatures()
+{
+	SERIAL_ECHO("[ST0:");
+	SERIAL_ECHO(target_temperature[0]);
+	SERIAL_ECHO("][STB:");
+	SERIAL_ECHO(target_temperature_bed);
+	SERIAL_ECHO("][AT0:");
+	SERIAL_ECHO(current_temperature[0]);
+	SERIAL_ECHO("][ATB:");
+	SERIAL_ECHO(current_temperature_bed);
+	SERIAL_ECHO(']');
+}
+
+static void prusa_stat_printinfo()
+{
+	SERIAL_ECHO("[TFU:");
+	SERIAL_ECHO(total_filament_used);
+	SERIAL_ECHO("][PCD:");
+	SERIAL_ECHO(itostr3(card.percentDone()));
+	SERIAL_ECHO("][FEM:");
+	SERIAL_ECHO(itostr3(feedmultiply));
+	SERIAL_ECHO("][FNM:");
+	SERIAL_ECHO(longFilenameOLD);
+	SERIAL_ECHO("][TIM:");
+	if (starttime != 0)
+	{
+		SERIAL_ECHO(_millis() / 1000 - starttime / 1000);
+	}
+	else
+	{
+		SERIAL_ECHO(0);
+	}
+	SERIAL_ECHO("][FWR:");
+	SERIAL_ECHO(FW_VERSION);
+	SERIAL_ECHO(']');
+    prusa_stat_diameter();
+}
+
+void prusa_statistics_err(char c){
+	SERIAL_ECHO("{[ERR:");
+	SERIAL_ECHO(c);
+	SERIAL_ECHO(']');
+	prusa_stat_farm_number();
+}
+
+void prusa_statistics_case0(uint8_t statnr){
+	SERIAL_ECHO("{");
+	prusa_stat_printerstatus(statnr);
+	prusa_stat_farm_number();
+	prusa_stat_printinfo();
+}
+
+void prusa_statistics(int _message, uint8_t _fil_nr) {
+#ifdef DEBUG_DISABLE_PRUSA_STATISTICS
+	return;
+#endif //DEBUG_DISABLE_PRUSA_STATISTICS
+	switch (_message)
+	{
+
+	case 0: // default message
+		if (busy_state == PAUSED_FOR_USER) 
+		{   
+			prusa_statistics_case0(15);
+		}
+		else if (isPrintPaused || card.paused) 
+		{
+			prusa_statistics_case0(14);
+		}
+		else if (IS_SD_PRINTING || loading_flag)
+		{
+			prusa_statistics_case0(4);
+		}
+		else
+		{
+			SERIAL_ECHO("{");
+			prusa_stat_printerstatus(1);
+			prusa_stat_farm_number();
+			prusa_stat_diameter();
+			status_number = 1;
+		}
+		break;
+
+	case 1:		// 1 heating
+		farm_status = 2;
+		SERIAL_ECHO('{');
+		prusa_stat_printerstatus(2);
+		prusa_stat_farm_number();
+		status_number = 2;
+		farm_timer = 1;
+		break;
+
+	case 2:		// heating done
+		farm_status = 3;
+		SERIAL_ECHO('{');
+		prusa_stat_printerstatus(3);
+		prusa_stat_farm_number();
+		SERIAL_ECHOLN('}');
+		status_number = 3;
+		farm_timer = 1;
+
+		if (IS_SD_PRINTING || loading_flag)
+		{
+			farm_status = 4;
+			SERIAL_ECHO('{');
+			prusa_stat_printerstatus(4);
+			prusa_stat_farm_number();
+			status_number = 4;
+		}
+		else
+		{
+			SERIAL_ECHO('{');
+			prusa_stat_printerstatus(3);
+			prusa_stat_farm_number();
+			status_number = 3;
+		}
+		farm_timer = 1;
+		break;
+
+	case 3:		// filament change
+		// must do a return here to prevent doing SERIAL_ECHOLN("}") at the very end of this function
+		// saved a considerable amount of FLASH
+		return;
+	case 4:		// print succesfull
+		SERIAL_ECHO("{[RES:1][FIL:");
+		MYSERIAL.print(int(_fil_nr));
+		SERIAL_ECHO(']');
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		farm_timer = 2;
+		break;
+	case 5:		// print not succesfull
+		SERIAL_ECHO("{[RES:0][FIL:");
+		MYSERIAL.print(int(_fil_nr));
+		SERIAL_ECHO(']');
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		farm_timer = 2;
+		break;
+	case 6:		// print done
+		SERIAL_ECHO("{[PRN:8]");
+		prusa_stat_farm_number();
+		status_number = 8;
+		farm_timer = 2;
+		break;
+	case 7:		// print done - stopped
+		SERIAL_ECHO("{[PRN:9]");
+		prusa_stat_farm_number();
+		status_number = 9;
+		farm_timer = 2;
+		break;
+	case 8:		// printer started
+		SERIAL_ECHO("{[PRN:0][PFN:");
+		status_number = 0;
+		SERIAL_ECHO(farm_no);
+		SERIAL_ECHO(']');
+		farm_timer = 2;
+		break;
+	case 20:		// echo farm no
+		SERIAL_ECHO('{');
+		prusa_stat_printerstatus(status_number);
+		prusa_stat_farm_number();
+		farm_timer = 4;
+		break;
+	case 21: // temperatures
+		SERIAL_ECHO('{');
+		prusa_stat_temperatures();
+		prusa_stat_farm_number();
+		prusa_stat_printerstatus(status_number);
+		break;
+    case 22: // waiting for filament change
+        SERIAL_ECHO("{[PRN:5]");
+		prusa_stat_farm_number();
+		status_number = 5;
+        break;
+	
+	case 90: // Error - Thermal Runaway
+		prusa_statistics_err('1');
+		break;
+	case 91: // Error - Thermal Runaway Preheat
+		prusa_statistics_err('2');
+		break;
+	case 92: // Error - Min temp
+		prusa_statistics_err('3');
+		break;
+	case 93: // Error - Max temp
+		prusa_statistics_err('4');
+		break;
+
+    case 99:		// heartbeat
+        SERIAL_ECHO("{[PRN:99]");
+        prusa_stat_temperatures();
+		SERIAL_ECHO("[PFN:");
+		SERIAL_ECHO(farm_no);
+		SERIAL_ECHO(']');
+            
+        break;
+	}
+	SERIAL_ECHOLN('}');	
+
+}
+
+} // end namespace new
+
+void SERIALS_RESET(){
+	old_code::SERIAL_RESET();
+	new_code::SERIAL_RESET();
+}
+
+std::string SERIALS_SERIALIZE(){
+	return old_code::SERIAL_BUFFER + "\n" + new_code::SERIAL_BUFFER;
+}
+void SERIALS_PRINT(){
+	std::cout << "[Printing buffers...] \n";
+	std::cout << old_code::SERIAL_BUFFER << "\n";
+	std::cout << new_code::SERIAL_BUFFER << "\n";
+}
+
+int SERIALS_COMPARE(){
+	// Trim the newline at the end
+
+	if(old_code::SERIAL_BUFFER.back() == '\n'){
+		old_code::SERIAL_BUFFER.pop_back();
+	}
+	if(new_code::SERIAL_BUFFER.back() == '\n'){
+		new_code::SERIAL_BUFFER.pop_back();
+	}
+
+	std::cout << "Comparing: \n";
+	std::cout << old_code::SERIAL_BUFFER << "\n";
+	std::cout << new_code::SERIAL_BUFFER << "\n";
+
+	return old_code::SERIAL_BUFFER.compare(new_code::SERIAL_BUFFER);
+}
+
+
+// ---------------  TEST CASES ---------------- // 
+
+TEST_CASE("Serials compare ignore newline at the end", "[helper]")
+{
+	SERIALS_RESET();
+	old_code::SERIAL_BUFFER = "Hello compare me.";
+	new_code::SERIAL_BUFFER = "Hello compare me.";
+	CHECK(SERIALS_COMPARE() == 0);
+
+	SERIALS_RESET();
+	old_code::SERIAL_BUFFER = "Hello compare me.\n";
+	new_code::SERIAL_BUFFER = "Hello compare me.";
+	CHECK(SERIALS_COMPARE() == 0);
+
+	SERIALS_RESET();
+	old_code::SERIAL_BUFFER = "Hello compare me.";
+	new_code::SERIAL_BUFFER = "Hello compare me.\n";
+	CHECK(SERIALS_COMPARE() == 0);
+}
+
+TEST_CASE("Printer status is shown", "[prusa_stats]")
+{
+	SERIALS_RESET();
+	setup_mockups();
+
+	old_code::prusa_stat_printerstatus(1);
+	new_code::prusa_stat_printerstatus(1);
+
+	INFO(SERIALS_SERIALIZE());
+	CHECK(SERIALS_COMPARE() == 0);
+}
+
+
+TEST_CASE("Printer info is shown", "[prusa_stats]")
+{
+	SERIALS_RESET();
+	setup_mockups();
+
+	old_code::prusa_stat_printinfo();
+	new_code::prusa_stat_printinfo();
+
+	INFO(SERIALS_SERIALIZE());
+	CHECK(SERIALS_COMPARE() == 0);
+}
+
+TEST_CASE("Printer temperatures are shown", "[prusa_stats]")
+{
+	SERIALS_RESET();
+	setup_mockups();
+
+	old_code::prusa_stat_temperatures();
+	new_code::prusa_stat_temperatures();
+	
+	INFO(SERIALS_SERIALIZE());
+	CHECK(SERIALS_COMPARE() == 0);
+}
+
+TEST_CASE("Prusa_statistics test", "[prusa_stats]")
+{
+	SERIALS_RESET();
+	setup_mockups();
+
+	int test_codes[] = {0,1,2,3,4,5,6,7,8,20,21,22,90,91,92,93,99};
+	int size = sizeof(test_codes)/sizeof(test_codes[0]);
+
+	for(int i = 0; i < size; i++){
+		std::cout << "Testing prusa_statistics(" << std::to_string(i) << ")\n";
+		
+		switch(i)
+		{
+			case 0: {
+				busy_state = 0;
+				PAUSED_FOR_USER = 0;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();
+
+				busy_state = 1;
+				PAUSED_FOR_USER = 0;
+				isPrintPaused = 1;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);	
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();
+
+				isPrintPaused = 0;
+				card.paused = 0;
+				IS_SD_PRINTING = 1;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();	
+
+				busy_state = 1;
+				PAUSED_FOR_USER = 0;	
+				isPrintPaused = 0;			
+				IS_SD_PRINTING = 0;
+				loading_flag = 0;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();	
+				break;
+			}
+			case 2: {
+				IS_SD_PRINTING = 1;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);	
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();	
+
+				IS_SD_PRINTING = 0;
+				loading_flag = 0;
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);	
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();					
+
+				break;
+			}
+			default:{
+
+				old_code::prusa_statistics(test_codes[i],0);
+				new_code::prusa_statistics(test_codes[i],0);
+				CHECK(SERIALS_COMPARE() == 0);
+				SERIALS_RESET();
+			}
+		}
+	}
+}