diff --git a/Marlin/enum.h b/Marlin/enum.h
index bad4b4dcf798d221d8cdec1582bf0b34f7cafe5d..1e993e9188a8de8595c9e4f8aa2aa373f99ff211 100755
--- a/Marlin/enum.h
+++ b/Marlin/enum.h
@@ -91,28 +91,6 @@ enum EndstopEnum {
Z2_MAX
};
-/**
- * Temperature
- * Stages in the ISR loop
- */
-enum TempState {
- PrepareTemp_0,
- MeasureTemp_0,
- PrepareTemp_BED,
- MeasureTemp_BED,
- PrepareTemp_1,
- MeasureTemp_1,
- PrepareTemp_2,
- MeasureTemp_2,
- PrepareTemp_3,
- MeasureTemp_3,
- PrepareTemp_4,
- MeasureTemp_4,
- Prepare_FILWIDTH,
- Measure_FILWIDTH,
- StartupDelay // Startup, delay initial temp reading a tiny bit so the hardware can settle
-};
-
#if ENABLED(EMERGENCY_PARSER)
enum e_parser_state {
state_RESET,
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 18ce9e26f1c03cd136f17b8aadbfbb15a2fbda40..ce95eaadf7454b2ceb1902db578eae540b941084 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -24,8 +24,6 @@
* temperature.cpp - temperature control
*/
-
-
#include "Marlin.h"
#include "ultralcd.h"
#include "temperature.h"
@@ -1538,8 +1536,8 @@ void Temperature::isr() {
CBI(TIMSK0, OCIE0B); //Disable Temperature ISR
sei();
- static uint8_t temp_count = 0;
- static TempState temp_state = StartupDelay;
+ static int8_t temp_count = -1;
+ static ADCSensorState adc_sensor_state = StartupDelay;
static uint8_t pwm_count = _BV(SOFT_PWM_SCALE);
// avoid multiple loads of pwm_count
uint8_t pwm_count_tmp = pwm_count;
@@ -1812,6 +1810,22 @@ void Temperature::isr() {
#endif // SLOW_PWM_HEATERS
+ //
+ // Update lcd buttons 488 times per second
+ //
+ static bool do_buttons;
+ if ((do_buttons ^= true)) lcd_buttons_update();
+
+ /**
+ * One sensor is sampled on every other call of the ISR.
+ * Each sensor is read 16 (OVERSAMPLENR) times, taking the average.
+ *
+ * On each Prepare pass, ADC is started for a sensor pin.
+ * On the next pass, the ADC value is read and accumulated.
+ *
+ * This gives each ADC 0.9765ms to charge up.
+ */
+
#define SET_ADMUX_ADCSRA(pin) ADMUX = _BV(REFS0) | (pin & 0x07); SBI(ADCSRA, ADSC)
#ifdef MUX5
#define START_ADC(pin) if (pin > 7) ADCSRB = _BV(MUX5); else ADCSRB = 0; SET_ADMUX_ADCSRA(pin)
@@ -1819,122 +1833,94 @@ void Temperature::isr() {
#define START_ADC(pin) ADCSRB = 0; SET_ADMUX_ADCSRA(pin)
#endif
- // Prepare or measure a sensor, each one every 14th frame
- switch (temp_state) {
- case PrepareTemp_0:
- #if HAS_TEMP_0
+ switch (adc_sensor_state) {
+
+ case SensorsReady: {
+ // All sensors have been read. Stay in this state for a few
+ // ISRs to save on calls to temp update/checking code below.
+ constexpr int extra_loops = MIN_ADC_ISR_LOOPS - (int)SensorsReady;
+ static uint8_t delay_count = 0;
+ if (extra_loops > 0) {
+ if (delay_count == 0) delay_count = extra_loops; // Init this delay
+ if (--delay_count) // While delaying...
+ adc_sensor_state = (ADCSensorState)(int(SensorsReady) - 1); // retain this state (else, next state will be 0)
+ break;
+ }
+ else
+ adc_sensor_state = (ADCSensorState)0; // Fall-through to start first sensor now
+ }
+
+ #if HAS_TEMP_0
+ case PrepareTemp_0:
START_ADC(TEMP_0_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_0;
- break;
- case MeasureTemp_0:
- #if HAS_TEMP_0
+ break;
+ case MeasureTemp_0:
raw_temp_value[0] += ADC;
- #endif
- temp_state = PrepareTemp_BED;
- break;
+ break;
+ #endif
- case PrepareTemp_BED:
- #if HAS_TEMP_BED
+ #if HAS_TEMP_BED
+ case PrepareTemp_BED:
START_ADC(TEMP_BED_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_BED;
- break;
- case MeasureTemp_BED:
- #if HAS_TEMP_BED
+ break;
+ case MeasureTemp_BED:
raw_temp_bed_value += ADC;
- #endif
- temp_state = PrepareTemp_1;
- break;
+ break;
+ #endif
- case PrepareTemp_1:
- #if HAS_TEMP_1
+ #if HAS_TEMP_1
+ case PrepareTemp_1:
START_ADC(TEMP_1_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_1;
- break;
- case MeasureTemp_1:
- #if HAS_TEMP_1
+ break;
+ case MeasureTemp_1:
raw_temp_value[1] += ADC;
- #endif
- temp_state = PrepareTemp_2;
- break;
+ break;
+ #endif
- case PrepareTemp_2:
- #if HAS_TEMP_2
+ #if HAS_TEMP_2
+ case PrepareTemp_2:
START_ADC(TEMP_2_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_2;
- break;
- case MeasureTemp_2:
- #if HAS_TEMP_2
+ break;
+ case MeasureTemp_2:
raw_temp_value[2] += ADC;
- #endif
- temp_state = PrepareTemp_3;
- break;
+ break;
+ #endif
- case PrepareTemp_3:
- #if HAS_TEMP_3
+ #if HAS_TEMP_3
+ case PrepareTemp_3:
START_ADC(TEMP_3_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_3;
- break;
- case MeasureTemp_3:
- #if HAS_TEMP_3
+ break;
+ case MeasureTemp_3:
raw_temp_value[3] += ADC;
- #endif
- temp_state = PrepareTemp_4;
- break;
+ break;
+ #endif
- case PrepareTemp_4:
- #if HAS_TEMP_4
+ #if HAS_TEMP_4
+ case PrepareTemp_4:
START_ADC(TEMP_4_PIN);
- #endif
- lcd_buttons_update();
- temp_state = MeasureTemp_4;
- break;
- case MeasureTemp_4:
- #if HAS_TEMP_4
+ break;
+ case MeasureTemp_4:
raw_temp_value[4] += ADC;
- #endif
- temp_state = Prepare_FILWIDTH;
- break;
+ break;
+ #endif
- case Prepare_FILWIDTH:
- #if ENABLED(FILAMENT_WIDTH_SENSOR)
+ #if ENABLED(FILAMENT_WIDTH_SENSOR)
+ case Prepare_FILWIDTH:
START_ADC(FILWIDTH_PIN);
- #endif
- lcd_buttons_update();
- temp_state = Measure_FILWIDTH;
break;
- case Measure_FILWIDTH:
- #if ENABLED(FILAMENT_WIDTH_SENSOR)
- // raw_filwidth_value += ADC; //remove to use an IIR filter approach
- if (ADC > 102) { //check that ADC is reading a voltage > 0.5 volts, otherwise don't take in the data.
- raw_filwidth_value -= (raw_filwidth_value >> 7); //multiply raw_filwidth_value by 127/128
- raw_filwidth_value += ((unsigned long)ADC << 7); //add new ADC reading
+ case Measure_FILWIDTH:
+ if (ADC > 102) { // Make sure ADC is reading > 0.5 volts, otherwise don't read.
+ raw_filwidth_value -= (raw_filwidth_value >> 7); // Subtract 1/128th of the raw_filwidth_value
+ raw_filwidth_value += ((unsigned long)ADC << 7); // Add new ADC reading, scaled by 128
}
- #endif
- temp_state = PrepareTemp_0;
- temp_count++;
- break;
+ break;
+ #endif
- case StartupDelay:
- temp_state = PrepareTemp_0;
- break;
+ case StartupDelay: break;
- // default:
- // SERIAL_ERROR_START;
- // SERIAL_ERRORLNPGM("Temp measurement error!");
- // break;
- } // switch(temp_state)
+ } // switch(adc_sensor_state)
- if (temp_count >= OVERSAMPLENR) { // 10 * 16 * 1/(16000000/64/256) = 164ms.
+ if (!adc_sensor_state && ++temp_count >= OVERSAMPLENR) { // 10 * 16 * 1/(16000000/64/256) = 164ms.
temp_count = 0;
@@ -1998,6 +1984,9 @@ void Temperature::isr() {
} // temp_count >= OVERSAMPLENR
+ // Go to the next state, up to SensorsReady
+ adc_sensor_state = (ADCSensorState)((int(adc_sensor_state) + 1) % int(StartupDelay));
+
#if ENABLED(BABYSTEPPING)
LOOP_XYZ(axis) {
int curTodo = babystepsTodo[axis]; //get rid of volatile for performance
diff --git a/Marlin/temperature.h b/Marlin/temperature.h
index 4e7e2a83ea9448dbae4dd64542f169b2bf7c4957..aaba9720039ddc8527aa470179f2c35e4c484c52 100644
--- a/Marlin/temperature.h
+++ b/Marlin/temperature.h
@@ -50,6 +50,49 @@
#define EXTRUDER_IDX active_extruder
#endif
+/**
+ * States for ADC reading in the ISR
+ */
+enum ADCSensorState {
+ #if HAS_TEMP_0
+ PrepareTemp_0,
+ MeasureTemp_0,
+ #endif
+ #if HAS_TEMP_1
+ PrepareTemp_1,
+ MeasureTemp_1,
+ #endif
+ #if HAS_TEMP_2
+ PrepareTemp_2,
+ MeasureTemp_2,
+ #endif
+ #if HAS_TEMP_3
+ PrepareTemp_3,
+ MeasureTemp_3,
+ #endif
+ #if HAS_TEMP_4
+ PrepareTemp_4,
+ MeasureTemp_4,
+ #endif
+ #if HAS_TEMP_BED
+ PrepareTemp_BED,
+ MeasureTemp_BED,
+ #endif
+ #if ENABLED(FILAMENT_WIDTH_SENSOR)
+ Prepare_FILWIDTH,
+ Measure_FILWIDTH,
+ #endif
+ SensorsReady, // Temperatures ready. Delay the next round of readings to let ADC pins settle.
+ StartupDelay // Startup, delay initial temp reading a tiny bit so the hardware can settle
+};
+
+// Minimum number of Temperature::ISR loops between sensor readings.
+// Multiplied by 16 (OVERSAMPLENR) to obtain the total time to
+// get all oversampled sensor readings
+#define MIN_ADC_ISR_LOOPS 10
+
+#define ACTUAL_ADC_SAMPLES max(int(MIN_ADC_ISR_LOOPS), int(SensorsReady))
+
class Temperature {
public:
@@ -74,7 +117,7 @@ class Temperature {
#endif
#if ENABLED(PIDTEMP) || ENABLED(PIDTEMPBED)
- #define PID_dT ((OVERSAMPLENR * 12.0)/(F_CPU / 64.0 / 256.0))
+ #define PID_dT ((OVERSAMPLENR * float(ACTUAL_ADC_SAMPLES)) / (F_CPU / 64.0 / 256.0))
#endif
#if ENABLED(PIDTEMP)