More descriptive environment error message

Marlin/src/pins/pins_AZSMZ_MINI.h

@@ -25,7 +25,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_AZTEEG_X5_GT.h

@@ -22,11 +22,11 @@
  */
 
 /**
- * MKS SBASE pin assignments
+ * Azteeg X5 GT pin assignments
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_BIQU_BQ111_A4.h

@@ -31,7 +31,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have Re-Arm selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_COHESION3D_MINI.h

@@ -26,7 +26,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_COHESION3D_REMIX.h

@@ -26,7 +26,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_MKS_SBASE.h

@@ -26,7 +26,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_RAMPS.h

@@ -45,7 +45,9 @@
  */
 
 #if ENABLED(TARGET_LPC1768)
-  #error "Oops!  Use 'BOARD_RAMPS_RE_ARM' to build for Re-ARM."
+  #error "Oops!  Set MOTHERBOARD to an LPC1768-based board when building for LPC1768."
+#elif defined(__STM32F1__)
+  #error "Oops!  Set MOTHERBOARD to an STM32F1-based board when building for STM32F1."
 #endif
 
 #if DISABLED(IS_RAMPS_SMART) && DISABLED(IS_RAMPS_DUO) && DISABLED(IS_RAMPS4DUE) && DISABLED(TARGET_LPC1768)

Marlin/src/pins/pins_RAMPS_RE_ARM.h

@@ -37,7 +37,7 @@
 // numbers in parenthesis () are the mega2560 equivalent pin numbers
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME

Marlin/src/pins/pins_SELENA_COMPACT.h

@@ -26,7 +26,7 @@
  */
 
 #ifndef TARGET_LPC1768
-  #error "Oops!  Make sure you have LPC1768 selected."
+  #error "Oops!  Make sure you have the LPC1768 environment selected in your IDE."
 #endif
 
 #ifndef BOARD_NAME