MINTEMP safety for ambient temperature < 18C

Silent mode acceleration limit lowered to 1000mm/s^2

Firmware/Configuration_prusa.h

@@ -75,8 +75,8 @@ const bool Z_MIN_ENDSTOP_INVERTING = false; // set to true to invert the logic o
 #define MANUAL_FEEDRATE {2700, 2700, 1000, 100}   // set the speeds for manual moves (mm/min)
 
 //Silent mode limits
-#define SILENT_MAX_ACCEL_X  1024 // X-axis max acceleration in silent mode in mm/s^2
-#define SILENT_MAX_ACCEL_Y  1024 // Y-axis max axxeleration in silent mode in mm/s^2
+#define SILENT_MAX_ACCEL_X  1000 // X-axis max acceleration in silent mode in mm/s^2
+#define SILENT_MAX_ACCEL_Y  1000 // Y-axis max axxeleration in silent mode in mm/s^2
 #define SILENT_MAX_ACCEL_X_ST (100*SILENT_MAX_ACCEL_X) // X max accel in steps/s^2
 #define SILENT_MAX_ACCEL_Y_ST (100*SILENT_MAX_ACCEL_Y) // Y max accel in steps/s^2
 #define SILENT_MAX_FEEDRATE 172  //max feedrate in mm/s, because mode switched to normal for homming , this value limits also homing, it should be greater (160mm/s=9600mm/min>2700mm/min)

Firmware/temperature.cpp

@@ -1908,9 +1908,8 @@ void check_max_temp()
 
 }
 
-void check_min_temp()
+void check_min_temp_heater0()
 {
-	if (current_temperature_raw_ambient > OVERSAMPLENR*MINTEMP_MINAMBIENT_RAW) return;
 //heater
 #if HEATER_0_RAW_LO_TEMP > HEATER_0_RAW_HI_TEMP
 	if (current_temperature_raw[0] >= minttemp_raw[0]) {
@@ -1919,7 +1918,10 @@ void check_min_temp()
 #endif
 		min_temp_error(0);
 	}
-//bed
+}
+
+void check_min_temp_bed()
+{
 #if HEATER_BED_RAW_LO_TEMP > HEATER_BED_RAW_HI_TEMP
 	if (current_temperature_bed_raw >= bed_minttemp_raw) {
 #else
@@ -1929,6 +1931,28 @@ void check_min_temp()
 	}
 }
 
+void check_min_temp()
+{
+	static uint8_t heat_cycles = 0;
+	if (current_temperature_raw_ambient > OVERSAMPLENR*MINTEMP_MINAMBIENT_RAW)
+	{
+		if (READ(HEATER_0_PIN) == HIGH)
+		{
+//			if ((heat_cycles % 10) == 0)
+//				printf_P(PSTR("X%d\n"), heat_cycles);
+			if (heat_cycles > 50) //reaction time 5-10s
+				check_min_temp_heater0();
+			else
+				heat_cycles++;
+		}
+		else
+			heat_cycles = 0;
+		return;
+	}
+	check_min_temp_heater0();
+	check_min_temp_bed();
+}
+
 void check_fans() {
 	if (READ(TACH_0) != fan_state[0]) {
 		fan_edge_counter[0] ++;