[Generic F4xx] Allow some re-definitions

USER_BTN and LED_BUILTIN can be redefined

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

variants/Generic_F401Cx/variant.h

@@ -77,7 +77,9 @@ extern "C" {
 #define LED_GREEN               LED_BUILTIN
 
 // On-board user button
+#ifndef USER_BTN
 #define USER_BTN                PC13
+#endif
 
 // SPI definitions
 #define PIN_SPI_SS              PA4

variants/Generic_F401Rx/variant.h

@@ -87,11 +87,15 @@ extern "C" {
 #define NUM_ANALOG_INPUTS       16
 
 // On-board LED pin number
+#ifndef LED_BUILTIN
 #define LED_BUILTIN             PA5
+#endif
 #define LED_GREEN               LED_BUILTIN
 
 // On-board user button
+#ifndef USER_BTN
 #define USER_BTN                PC13
+#endif
 
 // SPI definitions
 #define PIN_SPI_SS              PA4

variants/Generic_F410Rx/variant.h

@@ -95,7 +95,9 @@ extern "C" {
 #define LED_GREEN               LED_BUILTIN
 
 // On-board user button
+#ifndef USER_BTN
 #define USER_BTN                PC13
+#endif
 
 // Timer Definitions
 // Use TIM6/TIM7 when possible as servo and tone don't need GPIO output pin

variants/Generic_F411Cx/variant.h

@@ -78,7 +78,9 @@ extern "C" {
 #define LED_GREEN               LED_BUILTIN
 
 // On-board user button
+#ifndef USER_BTN
 #define USER_BTN                PC13
+#endif
 
 // SPI definitions
 #define PIN_SPI_SS              PA4

variants/Generic_F411Rx/variant.h

@@ -93,7 +93,9 @@ extern "C" {
 #define LED_GREEN               LED_BUILTIN
 
 // On-board user button
+#ifndef USER_BTN
 #define USER_BTN                PC13
+#endif
 
 // SPI definitions
 #define PIN_SPI_SS              PA4