MarlinFirmware · thinkyhead · Nov 17, 2018 · Dec 6, 2017
diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h
@@ -275,12 +275,12 @@
 #elif TEMP_SENSOR_0 == -3
   #define HEATER_0_USES_MAX6675
   #define MAX6675_IS_MAX31855
-  #define MAX6675_TMIN -270
-  #define MAX6675_TMAX 1800
+  #define HEATER_0_MAX6675_TMIN -270
+  #define HEATER_0_MAX6675_TMAX 1800
 #elif TEMP_SENSOR_0 == -2
   #define HEATER_0_USES_MAX6675
-  #define MAX6675_TMIN 0
-  #define MAX6675_TMAX 1024
+  #define HEATER_0_MAX6675_TMIN 0
+  #define HEATER_0_MAX6675_TMAX 1024
 #elif TEMP_SENSOR_0 == -1
   #define HEATER_0_USES_AD595
 #elif TEMP_SENSOR_0 == 0
@@ -294,9 +294,19 @@
 #if TEMP_SENSOR_1 == -4
   #define HEATER_1_USES_AD8495
 #elif TEMP_SENSOR_1 == -3
-  #error "MAX31855 Thermocouples (-3) not supported for TEMP_SENSOR_1."
+  #if TEMP_SENSOR_0 == -2
+    #error "If MAX31855 Thermocouple (-3) is used for TEMP_SENSOR_1 then TEMP_SENSOR_0 must match."
+  #endif
+  #define HEATER_1_USES_MAX6675
+  #define HEATER_1_MAX6675_TMIN -270
+  #define HEATER_1_MAX6675_TMAX 1800
 #elif TEMP_SENSOR_1 == -2
-  #error "MAX6675 Thermocouples (-2) not supported for TEMP_SENSOR_1."
+  #if TEMP_SENSOR_0 == -3
+    #error "If MAX31855 Thermocouple (-3) is used for TEMP_SENSOR_0 then TEMP_SENSOR_1 must match."
+  #endif
+  #define HEATER_1_USES_MAX6675
+  #define HEATER_1_MAX6675_TMIN 0
+  #define HEATER_1_MAX6675_TMAX 1024
 #elif TEMP_SENSOR_1 == -1
   #define HEATER_1_USES_AD595
 #elif TEMP_SENSOR_1 == 0

diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
@@ -335,6 +335,10 @@
   #error "MBL_Z_STEP is now MESH_EDIT_Z_STEP. Please update your configuration."
 #elif defined(CHDK)
   #error "CHDK is now CHDK_PIN. Please update your Configuration_adv.h."
+#elif defined(MAX6675_SS)
+  #error "MAX6675_SS is now MAX6675_SS_PIN. Please update your configuration and/or pins."
+#elif defined(MAX6675_SS2)
+  #error "MAX6675_SS2 is now MAX6675_SS2_PIN. Please update your configuration and/or pins."
 #endif
 
 #define BOARD_MKS_13     -47
@@ -1280,7 +1284,7 @@ static_assert(X_MAX_LENGTH >= X_BED_SIZE && Y_MAX_LENGTH >= Y_BED_SIZE,
  */
 #if !HAS_HEATER_0
   #error "HEATER_0_PIN not defined for this board."
-#elif !PIN_EXISTS(TEMP_0) && !(defined(MAX6675_SS) && MAX6675_SS >= 0)
+#elif !PIN_EXISTS(TEMP_0) && !PIN_EXISTS(MAX6675_SS)
   #error "TEMP_0_PIN not defined for this board."
 #elif ((defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)) && (!PIN_EXISTS(E0_STEP) || !PIN_EXISTS(E0_DIR)))
   #error "E0_STEP_PIN or E0_DIR_PIN not defined for this board."
@@ -1291,16 +1295,18 @@ static_assert(X_MAX_LENGTH >= X_BED_SIZE && Y_MAX_LENGTH >= Y_BED_SIZE,
 #endif
 
 // Pins are required for heaters
-#if ENABLED(HEATER_0_USES_MAX6675) && !(defined(MAX6675_SS) && MAX6675_SS >= 0)
-  #error "MAX6675_SS (required for TEMP_SENSOR_0) not defined for this board."
+#if ENABLED(HEATER_0_USES_MAX6675) && !PIN_EXISTS(MAX6675_SS)
+  #error "MAX6675_SS_PIN (required for TEMP_SENSOR_0) not defined for this board."
 #elif (HOTENDS > 1 || ENABLED(HEATERS_PARALLEL)) && !HAS_HEATER_1
   #error "HEATER_1_PIN not defined for this board."
 #endif
 
 #if HOTENDS > 1
-  #if TEMP_SENSOR_1 == 0
+  #if ENABLED(HEATER_1_USES_MAX6675) && !PIN_EXISTS(MAX6675_SS2)
+    #error "MAX6675_SS2_PIN (required for TEMP_SENSOR_1) not defined for this board."
+  #elif TEMP_SENSOR_1 == 0
     #error "TEMP_SENSOR_1 is required with 2 or more HOTENDS."
-  #elif !PIN_EXISTS(TEMP_1)
+  #elif !PIN_EXISTS(TEMP_1) && !PIN_EXISTS(MAX6675_SS2)
     #error "TEMP_1_PIN not defined for this board."
   #endif
   #if HOTENDS > 2

diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
@@ -775,8 +775,13 @@ void Temperature::manage_heater() {
   updateTemperaturesFromRawValues(); // also resets the watchdog
 
   #if ENABLED(HEATER_0_USES_MAX6675)
-    if (current_temperature[0] > MIN(HEATER_0_MAXTEMP, MAX6675_TMAX - 1.0)) max_temp_error(0);
-    if (current_temperature[0] < MAX(HEATER_0_MINTEMP, MAX6675_TMIN + .01)) min_temp_error(0);
+    if (current_temperature[0] > MIN(HEATER_0_MAXTEMP, HEATER_0_MAX6675_TMAX - 1.0)) max_temp_error(0);
+    if (current_temperature[0] < MAX(HEATER_0_MINTEMP, HEATER_0_MAX6675_TMIN + .01)) min_temp_error(0);
+  #endif
+
+  #if ENABLED(HEATER_1_USES_MAX6675)
+    if (current_temperature[1] > MIN(HEATER_1_MAXTEMP, HEATER_1_MAX6675_TMAX - 1.0)) max_temp_error(1);
+    if (current_temperature[1] < MAX(HEATER_1_MINTEMP, HEATER_1_MAX6675_TMIN + .01)) min_temp_error(1);
   #endif
 
   #if WATCH_HOTENDS || WATCH_THE_BED || DISABLED(PIDTEMPBED) || HAS_AUTO_FAN || HEATER_IDLE_HANDLER
@@ -953,7 +958,9 @@ float Temperature::analog_to_celsius_hotend(const int raw, const uint8_t e) {
         break;
       #endif
     case 1:
-      #if ENABLED(HEATER_1_USES_AD595)
+      #if ENABLED(HEATER_1_USES_MAX6675)
+        return raw * 0.25;
+      #elif ENABLED(HEATER_1_USES_AD595)
         return TEMP_AD595(raw);
       #elif ENABLED(HEATER_1_USES_AD8495)
         return TEMP_AD8495(raw);
@@ -1036,7 +1043,10 @@ float Temperature::analog_to_celsius_hotend(const int raw, const uint8_t e) {
  */
 void Temperature::updateTemperaturesFromRawValues() {
   #if ENABLED(HEATER_0_USES_MAX6675)
-    current_temperature_raw[0] = read_max6675();
+    current_temperature_raw[0] = READ_MAX6675(0);
+  #endif
+  #if ENABLED(HEATER_1_USES_MAX6675)
+    current_temperature_raw[1] = READ_MAX6675(1);
   #endif
   HOTEND_LOOP() current_temperature[e] = analog_to_celsius_hotend(current_temperature_raw[e], e);
   #if HAS_HEATED_BED
@@ -1170,10 +1180,14 @@ void Temperature::init() {
     max6675_spi.init();
 
     OUT_WRITE(SS_PIN, HIGH);
-    OUT_WRITE(MAX6675_SS, HIGH);
+    OUT_WRITE(MAX6675_SS_PIN, HIGH);
 
   #endif // HEATER_0_USES_MAX6675
 
+  #if ENABLED(HEATER_1_USES_MAX6675)
+    OUT_WRITE(MAX6675_SS2_PIN, HIGH);
+  #endif
+
   HAL_adc_init();
 
   #if HAS_TEMP_ADC_0
@@ -1595,47 +1609,71 @@ void Temperature::disable_all_heaters() {
 
 #endif // PROBING_HEATERS_OFF
 
-#if ENABLED(HEATER_0_USES_MAX6675)
-
-  #define MAX6675_HEAT_INTERVAL 250u
+#if HAS_MAX6675
 
-  #if ENABLED(MAX6675_IS_MAX31855)
-    uint32_t max6675_temp = 2000;
-    #define MAX6675_ERROR_MASK 7
-    #define MAX6675_DISCARD_BITS 18
-    #define MAX6675_SPEED_BITS 3  // (_BV(SPR1)) // clock ÷ 64
-  #else
-    uint16_t max6675_temp = 2000;
-    #define MAX6675_ERROR_MASK 4
-    #define MAX6675_DISCARD_BITS 3
-    #define MAX6675_SPEED_BITS 2 // (_BV(SPR0)) // clock ÷ 16
-  #endif
+  int Temperature::read_max6675(
+    #if COUNT_6675 > 1
+      const uint8_t hindex
+    #endif
+  ) {
+    #if COUNT_6675 == 1
+      constexpr uint8_t hindex = 0;
+    #endif
 
-  int Temperature::read_max6675() {
+    #define MAX6675_HEAT_INTERVAL 250UL
 
-    static millis_t next_max6675_ms = 0;
+    #if ENABLED(MAX6675_IS_MAX31855)
+      static uint32_t max6675_temp = 2000;
+      #define MAX6675_ERROR_MASK    7
+      #define MAX6675_DISCARD_BITS 18
+      #define MAX6675_SPEED_BITS    3  // (_BV(SPR1)) // clock ÷ 64
+    #else
+      static uint16_t max6675_temp = 2000;
+      #define MAX6675_ERROR_MASK    4
+      #define MAX6675_DISCARD_BITS  3
+      #define MAX6675_SPEED_BITS    2  // (_BV(SPR0)) // clock ÷ 16
+    #endif
 
+    // Return last-read value between readings
+    static millis_t next_max6675_ms[COUNT_6675] = { 0 };
     millis_t ms = millis();
+    if (PENDING(ms, next_max6675_ms[hindex])) return int(max6675_temp);
+    next_max6675_ms[hindex] = ms + MAX6675_HEAT_INTERVAL;
 
-    if (PENDING(ms, next_max6675_ms)) return (int)max6675_temp;
-
-    next_max6675_ms = ms + MAX6675_HEAT_INTERVAL;
+    //
+    // TODO: spiBegin, spiRec and spiInit doesn't work when soft spi is used.
+    //
+    #if MB(MIGHTYBOARD_REVE)
+      spiBegin();
+      spiInit(MAX6675_SPEED_BITS);
+    #endif
 
-    spiBegin();
-    spiInit(MAX6675_SPEED_BITS);
+    #if COUNT_6675 > 1
+      #define WRITE_MAX6675(V) do{ switch (hindex) { case 1: WRITE(MAX6675_SS2_PIN, V); break; default: WRITE(MAX6675_SS_PIN, V); } }while(0)
+    #elif ENABLED(HEATER_1_USES_MAX6675)
+      #define WRITE_MAX6675(V) WRITE(MAX6675_SS2_PIN, V)
+    #else
+      #define WRITE_MAX6675(V) WRITE(MAX6675_SS_PIN, V)
+    #endif
 
-    WRITE(MAX6675_SS, 0); // enable TT_MAX6675
+    WRITE_MAX6675(LOW);  // enable TT_MAX6675
 
     DELAY_NS(100);       // Ensure 100ns delay
 
     // Read a big-endian temperature value
     max6675_temp = 0;
     for (uint8_t i = sizeof(max6675_temp); i--;) {
-      max6675_temp |= spiRec();
+      max6675_temp |= (
+        #if MB(MIGHTYBOARD_REVE)
+          max6675_spi.receive()
+        #else
+          spiRec()
+        #endif
+      );
       if (i > 0) max6675_temp <<= 8; // shift left if not the last byte
     }
 
-    WRITE(MAX6675_SS, 1); // disable TT_MAX6675
+    WRITE_MAX6675(HIGH); // disable TT_MAX6675
 
     if (max6675_temp & MAX6675_ERROR_MASK) {
       SERIAL_ERROR_START();
@@ -1651,7 +1689,17 @@ void Temperature::disable_all_heaters() {
       #else
         SERIAL_ERRORLNPGM("MAX6675");
       #endif
-      max6675_temp = MAX6675_TMAX * 4; // thermocouple open
+
+      // Thermocouple open
+      max6675_temp = 4 * (
+        #if COUNT_6675 > 1
+          hindex ? HEATER_1_MAX6675_TMAX : HEATER_0_MAX6675_TMAX
+        #elif ENABLED(HEATER_1_USES_MAX6675)
+          HEATER_1_MAX6675_TMAX
+        #else
+          HEATER_0_MAX6675_TMAX
+        #endif
+      );
     }
     else
       max6675_temp >>= MAX6675_DISCARD_BITS;
@@ -1660,24 +1708,28 @@ void Temperature::disable_all_heaters() {
         if (max6675_temp & 0x00002000) max6675_temp |= 0xFFFFC000;
       #endif
 
-    return (int)max6675_temp;
+    return int(max6675_temp);
   }
 
-#endif // HEATER_0_USES_MAX6675
+#endif // HAS_MAX6675
 
 /**
  * Get raw temperatures
  */
 void Temperature::set_current_temp_raw() {
+
   #if HAS_TEMP_ADC_0 && DISABLED(HEATER_0_USES_MAX6675)
     current_temperature_raw[0] = raw_temp_value[0];
   #endif
+
   #if HAS_TEMP_ADC_1
+
     #if ENABLED(TEMP_SENSOR_1_AS_REDUNDANT)
       redundant_temperature_raw = raw_temp_value[1];
-    #else
+    #elif DISABLED(HEATER_1_USES_MAX6675)
       current_temperature_raw[1] = raw_temp_value[1];
     #endif
+
     #if HAS_TEMP_ADC_2
       current_temperature_raw[2] = raw_temp_value[2];
       #if HAS_TEMP_ADC_3
@@ -1690,6 +1742,7 @@ void Temperature::set_current_temp_raw() {
         #endif // HAS_TEMP_ADC_4
       #endif // HAS_TEMP_ADC_3
     #endif // HAS_TEMP_ADC_2
+
   #endif // HAS_TEMP_ADC_1
 
   #if HAS_HEATED_BED
@@ -1771,17 +1824,17 @@ void Temperature::readings_ready() {
 
   #if HAS_HEATED_BED
     #if HEATER_BED_RAW_LO_TEMP > HEATER_BED_RAW_HI_TEMP
-      #define GEBED <=
+      #define BEDCMP(A,B) ((A)<=(B))
     #else
-      #define GEBED >=
+      #define BEDCMP(A,B) ((A)>=(B))
     #endif
     const bool bed_on = (target_temperature_bed > 0)
       #if ENABLED(PIDTEMPBED)
         || (soft_pwm_amount_bed > 0)
       #endif
     ;
-    if (current_temperature_bed_raw GEBED bed_maxttemp_raw) max_temp_error(-1);
-    if (bed_minttemp_raw GEBED current_temperature_bed_raw && bed_on) min_temp_error(-1);
+    if (BEDCMP(current_temperature_bed_raw, bed_maxttemp_raw)) max_temp_error(-1);
+    if (BEDCMP(bed_minttemp_raw, current_temperature_bed_raw) && bed_on) min_temp_error(-1);
   #endif
 }
 

diff --git a/Marlin/src/module/temperature.h b/Marlin/src/module/temperature.h
@@ -632,8 +632,23 @@ class Temperature {
 
     static void updateTemperaturesFromRawValues();
 
-    #if ENABLED(HEATER_0_USES_MAX6675)
-      static int read_max6675();
+    #define HAS_MAX6675 (ENABLED(HEATER_0_USES_MAX6675) || ENABLED(HEATER_1_USES_MAX6675))
+    #if HAS_MAX6675
+      #if ENABLED(HEATER_0_USES_MAX6675) && ENABLED(HEATER_1_USES_MAX6675)
+        #define COUNT_6675 2
+      #else
+        #define COUNT_6675 1
+      #endif
+      #if COUNT_6675 > 1
+        #define READ_MAX6675(N) read_max6675(N)
+      #else
+        #define READ_MAX6675(N) read_max6675()
+      #endif
+      static int read_max6675(
+        #if COUNT_6675 > 1
+          const uint8_t hindex=0
+        #endif
+      );
     #endif
 
     static void checkExtruderAutoFans();

diff --git a/Marlin/src/pins/pinsDebug_list.h b/Marlin/src/pins/pinsDebug_list.h
@@ -572,8 +572,11 @@
 #if PIN_EXISTS(MAX6675_SCK)
   REPORT_NAME_DIGITAL(__LINE__, MAX6675_SCK_PIN)
 #endif
-#if defined(MAX6675_SS) && MAX6675_SS >= 0
-  REPORT_NAME_DIGITAL(__LINE__, MAX6675_SS)
+#if PIN_EXISTS(MAX6675_SS)
+  REPORT_NAME_DIGITAL(__LINE__, MAX6675_SS_PIN)
+#endif
+#if PIN_EXISTS(MAX6675_SS2)
+  REPORT_NAME_DIGITAL(__LINE__, MAX6675_SS2_PIN)
 #endif
 // #if defined(MISO) && MISO >= 0
 //   REPORT_NAME_DIGITAL(__LINE__, MISO)
@@ -803,11 +806,11 @@
 #if PIN_EXISTS(SUICIDE)
   REPORT_NAME_DIGITAL(__LINE__, SUICIDE_PIN)
 #endif
-#if defined(THERMO_CS1) && THERMO_CS1 >= 0
-  REPORT_NAME_DIGITAL(__LINE__, THERMO_CS1)
+#if PIN_EXISTS(THERMO_CS1)
+  REPORT_NAME_DIGITAL(__LINE__, THERMO_CS1_PIN)
 #endif
-#if defined(THERMO_CS2) && THERMO_CS2 >= 0
-  REPORT_NAME_DIGITAL(__LINE__, THERMO_CS2)
+#if PIN_EXISTS(THERMO_CS2)
+  REPORT_NAME_DIGITAL(__LINE__, THERMO_CS2_PIN)
 #endif
 #if PIN_EXISTS(THERMO_DO)
   REPORT_NAME_DIGITAL(__LINE__, THERMO_DO_PIN)

diff --git a/Marlin/src/pins/pins_DUE3DOM.h b/Marlin/src/pins/pins_DUE3DOM.h
@@ -85,9 +85,9 @@
 
 // SPI for Max6675 or Max31855 Thermocouple
 #if DISABLED(SDSUPPORT)
-  #define MAX6675_SS        -1
+  #define MAX6675_SS_PIN   -1
 #else
-  #define MAX6675_SS        -1
+  #define MAX6675_SS_PIN   -1
 #endif
 
 //

diff --git a/Marlin/src/pins/pins_DUE3DOM_MINI.h b/Marlin/src/pins/pins_DUE3DOM_MINI.h
@@ -77,9 +77,9 @@
 
 // SPI for Max6675 or Max31855 Thermocouple
 #if DISABLED(SDSUPPORT)
-  #define MAX6675_SS       53
+  #define MAX6675_SS_PIN   53
 #else
-  #define MAX6675_SS       53
+  #define MAX6675_SS_PIN   53
 #endif
 
 //