diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 558f8ac1db5..68396fdb367 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -9468,7 +9468,7 @@ inline void gcode_M226() {
/**
* M303: PID relay autotune
*
- * S<temperature> sets the target temperature. (default 150C)
+ * S<temperature> sets the target temperature. (default 150C / 70C)
* E<extruder> (-1 for the bed) (default 0)
* C<cycles>
* U<bool> with a non-zero value will apply the result to current settings
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 6add38795bf..a141749313d 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -217,8 +217,8 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
* Alternately heat and cool the nozzle, observing its behavior to
* determine the best PID values to achieve a stable temperature.
*/
- void Temperature::PID_autotune(const float temp, const int8_t hotend, const int8_t ncycles, const bool set_result/*=false*/) {
- float input = 0.0;
+ void Temperature::PID_autotune(const float &target, const int8_t hotend, const int8_t ncycles, const bool set_result/*=false*/) {
+ float current = 0.0;
int cycles = 0;
bool heating = true;
@@ -230,34 +230,19 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
workKp = 0, workKi = 0, workKd = 0,
max = 0, min = 10000;
+ #define HAS_TP_BED (ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED))
+ #if HAS_TP_BED && ENABLED(THERMAL_PROTECTION_HOTENDS) && ENABLED(PIDTEMP)
+ #define TV(B,H) (hotend < 0 ? (B) : (H))
+ #elif HAS_TP_BED
+ #define TV(B,H) (B)
+ #else
+ #define TV(B,H) (H)
+ #endif
+
#if WATCH_THE_BED || WATCH_HOTENDS
- const float watch_temp_target = temp -
- #if ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED) && ENABLED(THERMAL_PROTECTION_HOTENDS) && ENABLED(PIDTEMP)
- (hotend < 0 ? (WATCH_BED_TEMP_INCREASE + TEMP_BED_HYSTERESIS + 1) : (WATCH_TEMP_INCREASE + TEMP_HYSTERESIS + 1))
- #elif ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED)
- (WATCH_BED_TEMP_INCREASE + TEMP_BED_HYSTERESIS + 1)
- #else
- (WATCH_TEMP_INCREASE + TEMP_HYSTERESIS + 1)
- #endif
- ;
- const int8_t watch_temp_period =
- #if ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED) && ENABLED(THERMAL_PROTECTION_HOTENDS) && ENABLED(PIDTEMP)
- hotend < 0 ? WATCH_BED_TEMP_PERIOD : WATCH_TEMP_PERIOD
- #elif ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED)
- WATCH_BED_TEMP_PERIOD
- #else
- WATCH_TEMP_PERIOD
- #endif
- ;
- const int8_t watch_temp_increase =
- #if ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED) && ENABLED(THERMAL_PROTECTION_HOTENDS) && ENABLED(PIDTEMP)
- hotend < 0 ? WATCH_BED_TEMP_INCREASE : WATCH_TEMP_INCREASE
- #elif ENABLED(THERMAL_PROTECTION_BED) && ENABLED(PIDTEMPBED)
- WATCH_BED_TEMP_INCREASE
- #else
- WATCH_TEMP_INCREASE
- #endif
- ;
+ const int8_t watch_temp_period = TV(WATCH_BED_TEMP_PERIOD, WATCH_TEMP_PERIOD),
+ watch_temp_increase = TV(WATCH_BED_TEMP_INCREASE, WATCH_TEMP_INCREASE);
+ const float watch_temp_target = target - float(watch_temp_increase + TV(TEMP_BED_HYSTERESIS, TEMP_HYSTERESIS) + 1);
millis_t temp_change_ms = next_temp_ms + watch_temp_period * 1000UL;
float next_watch_temp = 0.0;
bool heated = false;
@@ -298,7 +283,7 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
soft_pwm_amount_bed = bias = d = (MAX_BED_POWER) >> 1;
#endif
- wait_for_heatup = true;
+ wait_for_heatup = true; // Can be interrupted with M108
// PID Tuning loop
while (wait_for_heatup) {
@@ -308,7 +293,8 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
if (temp_meas_ready) { // temp sample ready
updateTemperaturesFromRawValues();
- input =
+ // Get the current temperature and constrain it
+ current =
#if HAS_PID_FOR_BOTH
hotend < 0 ? current_temperature_bed : current_temperature[hotend]
#elif ENABLED(PIDTEMP)
@@ -317,9 +303,8 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
current_temperature_bed
#endif
;
-
- NOLESS(max, input);
- NOMORE(min, input);
+ NOLESS(max, current);
+ NOMORE(min, current);
#if HAS_AUTO_FAN
if (ELAPSED(ms, next_auto_fan_check_ms)) {
@@ -328,7 +313,7 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
}
#endif
- if (heating && input > temp) {
+ if (heating && current > target) {
if (ELAPSED(ms, t2 + 5000UL)) {
heating = false;
#if HAS_PID_FOR_BOTH
@@ -343,11 +328,11 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
#endif
t1 = ms;
t_high = t1 - t2;
- max = temp;
+ max = target;
}
}
- if (!heating && input < temp) {
+ if (!heating && current < target) {
if (ELAPSED(ms, t1 + 5000UL)) {
heating = true;
t2 = ms;
@@ -411,41 +396,48 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS],
soft_pwm_amount_bed = (bias + d) >> 1;
#endif
cycles++;
- min = temp;
+ min = target;
}
}
}
+
+ // Did the temperature overshoot very far?
#define MAX_OVERSHOOT_PID_AUTOTUNE 20
- if (input > temp + MAX_OVERSHOOT_PID_AUTOTUNE) {
+ if (current > target + MAX_OVERSHOOT_PID_AUTOTUNE) {
SERIAL_PROTOCOLLNPGM(MSG_PID_TEMP_TOO_HIGH);
break;
}
- // Every 2 seconds...
+
+ // Report heater states every 2 seconds
if (ELAPSED(ms, next_temp_ms)) {
#if HAS_TEMP_HOTEND || HAS_TEMP_BED
print_heaterstates();
SERIAL_EOL();
#endif
-
next_temp_ms = ms + 2000UL;
+ // Make sure heating is actually working
#if WATCH_THE_BED || WATCH_HOTENDS
- if (!heated && input > next_watch_temp) {
- if (input > watch_temp_target) heated = true;
- next_watch_temp = input + watch_temp_increase;
- temp_change_ms = ms + watch_temp_period * 1000UL;
+ if (!heated) { // If not yet reached target...
+ if (current > next_watch_temp) { // Over the watch temp?
+ next_watch_temp = current + watch_temp_increase; // - set the next temp to watch for
+ temp_change_ms = ms + watch_temp_period * 1000UL; // - move the expiration timer up
+ if (current > watch_temp_target) heated = true; // - Flag if target temperature reached
+ }
+ else if (ELAPSED(ms, temp_change_ms)) // Watch timer expired
+ _temp_error(hotend, PSTR(MSG_T_HEATING_FAILED), PSTR(MSG_HEATING_FAILED_LCD));
}
- else if (!heated && ELAPSED(ms, temp_change_ms))
- _temp_error(hotend, PSTR(MSG_T_HEATING_FAILED), PSTR(MSG_HEATING_FAILED_LCD));
- else if (heated && input < temp - MAX_OVERSHOOT_PID_AUTOTUNE)
+ else if (current < target - (MAX_OVERSHOOT_PID_AUTOTUNE)) // Heated, then temperature fell too far?
_temp_error(hotend, PSTR(MSG_T_THERMAL_RUNAWAY), PSTR(MSG_THERMAL_RUNAWAY));
#endif
} // every 2 seconds
+
// Timeout after 20 minutes since the last undershoot/overshoot cycle
if (((ms - t1) + (ms - t2)) > (20L * 60L * 1000L)) {
SERIAL_PROTOCOLLNPGM(MSG_PID_TIMEOUT);
break;
}
+
if (cycles > ncycles) {
SERIAL_PROTOCOLLNPGM(MSG_PID_AUTOTUNE_FINISHED);
diff --git a/Marlin/temperature.h b/Marlin/temperature.h
index 037fa2d0fa2..d8aca8a53f2 100644
--- a/Marlin/temperature.h
+++ b/Marlin/temperature.h
@@ -453,7 +453,7 @@ class Temperature {
* Perform auto-tuning for hotend or bed in response to M303
*/
#if HAS_PID_HEATING
- static void PID_autotune(const float temp, const int8_t hotend, const int8_t ncycles, const bool set_result=false);
+ static void PID_autotune(const float &target, const int8_t hotend, const int8_t ncycles, const bool set_result=false);
/**
* Update the temp manager when PID values change