Add CreatorPro / Makerbot / QIDI / etc and Mightboard RevE support (#12855)

- Fix a bug in MAXxxxx thermocouple temp reporting.
- Add support for 3-wire HD44780.
- Add support for PCA9533 RGB driver.
- Add configuration examples for FlashForge CreatorPro.

Marlin/src/module/temperature.cpp

@@ -1739,6 +1739,9 @@ void Temperature::disable_all_heaters() {
   ) {
     #if COUNT_6675 == 1
       constexpr uint8_t hindex = 0;
+    #else
+      // Needed to return the correct temp when this is called too soon
+      static uint16_t max6675_temp_previous[COUNT_6675] = { 0 };
     #endif
 
     #define MAX6675_HEAT_INTERVAL 250UL
@@ -1758,7 +1761,15 @@ void Temperature::disable_all_heaters() {
     // 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);
+    if (PENDING(ms, next_max6675_ms[hindex]))
+      return int(
+        #if COUNT_6675 == 1
+          max6675_temp
+        #else
+          max6675_temp_previous[hindex] // Need to return the correct previous value
+        #endif
+      );
+
     next_max6675_ms[hindex] = ms + MAX6675_HEAT_INTERVAL;
 
     //
@@ -1824,10 +1835,14 @@ void Temperature::disable_all_heaters() {
     }
     else
       max6675_temp >>= MAX6675_DISCARD_BITS;
-      #if ENABLED(MAX6675_IS_MAX31855)
-        // Support negative temperature
-        if (max6675_temp & 0x00002000) max6675_temp |= 0xFFFFC000;
-      #endif
+
+    #if ENABLED(MAX6675_IS_MAX31855)
+      if (max6675_temp & 0x00002000) max6675_temp |= 0xFFFFC000; // Support negative temperature
+    #endif
+
+    #if COUNT_6675 > 1
+      max6675_temp_previous[hindex] = max6675_temp;
+    #endif
 
     return int(max6675_temp);
   }