Now able to use ADC_CHANNEL_RSSI as ADC input (#3524)

Example of use <configure name="ADC_AIRSPEED" value="ADC_CHANNEL_RSSI"/> , however a flightcontroller board file must have a RSSI pin assigned else it is not assignable.

sw/airborne/boards/px4fmu/chibios/v4.0/board.cfg

@@ -99,7 +99,7 @@ PB14    FRAM_MISO           SPI     AF:SPI2_MISO
 PB15    FRAM_MOSI           SPI     AF:SPI2_MOSI
 
 PC00    VBUS_VALID          PASSIVE
-PC01    RSSI_IN             PASSIVE
+PC01    RSSI_IN             ADC     ADC1_IN11
 PC02    MPU9250_CS          OUTPUT  PUSHPULL  SPEED_HIGH FLOATING LEVEL_HIGH
 PC03    LED_SAFETY          LED                    
 PC04    SAFETY_SW_IN        INPUT   FLOATING

sw/airborne/boards/px4fmu/chibios/v4.0/board.h

@@ -555,7 +555,7 @@
 					 PIN_AFIO_AF(FRAM_MOSI, 5))
 
 #define VAL_GPIOC_MODER                 (PIN_MODE_INPUT(VBUS_VALID) | \
-					 PIN_MODE_INPUT(RSSI_IN) | \
+					 PIN_MODE_ANALOG(RSSI_IN) | \
 					 PIN_MODE_OUTPUT(MPU9250_CS) | \
 					 PIN_MODE_OUTPUT(LED_SAFETY) | \
 					 PIN_MODE_INPUT(SAFETY_SW_IN) | \
@@ -572,7 +572,7 @@
 					 PIN_MODE_OUTPUT(_20608_CS))
 
 #define VAL_GPIOC_OTYPER                (PIN_OTYPE_OPENDRAIN(VBUS_VALID) | \
-					 PIN_OTYPE_OPENDRAIN(RSSI_IN) | \
+					 PIN_OTYPE_PUSHPULL(RSSI_IN) | \
 					 PIN_OTYPE_PUSHPULL(MPU9250_CS) | \
 					 PIN_OTYPE_PUSHPULL(LED_SAFETY) | \
 					 PIN_OTYPE_OPENDRAIN(SAFETY_SW_IN) | \
@@ -606,7 +606,7 @@
 					 PIN_OSPEED_SPEED_HIGH(_20608_CS))
 
 #define VAL_GPIOC_PUPDR                 (PIN_PUPDR_PULLDOWN(VBUS_VALID) | \
-					 PIN_PUPDR_PULLDOWN(RSSI_IN) | \
+					 PIN_PUPDR_FLOATING(RSSI_IN) | \
 					 PIN_PUPDR_FLOATING(MPU9250_CS) | \
 					 PIN_PUPDR_FLOATING(LED_SAFETY) | \
 					 PIN_PUPDR_FLOATING(SAFETY_SW_IN) | \
@@ -623,7 +623,7 @@
 					 PIN_PUPDR_FLOATING(_20608_CS))
 
 #define VAL_GPIOC_ODR                   (PIN_ODR_LEVEL_HIGH(VBUS_VALID) | \
-					 PIN_ODR_LEVEL_HIGH(RSSI_IN) | \
+					 PIN_ODR_LEVEL_LOW(RSSI_IN) | \
 					 PIN_ODR_LEVEL_HIGH(MPU9250_CS) | \
 					 PIN_ODR_LEVEL_LOW(LED_SAFETY) | \
 					 PIN_ODR_LEVEL_LOW(SAFETY_SW_IN) | \
@@ -1593,6 +1593,9 @@
 #define SERVO1_TIM_FN	 CH
 #define SERVO1_TIM_CH	 4
 #define SERVO1_TIM_AF	 1
+#define RSSI_IN_ADC	 1
+#define RSSI_IN_ADC_FN	 IN
+#define RSSI_IN_ADC_IN	 11
 
 #define BOARD_GROUP_DECLFOREACH(line, group) \
   static const ioline_t group ## _ARRAY[] = {group}; \

sw/airborne/boards/px4fmu/chibios/v4.0/px4fmu.h

@@ -67,7 +67,7 @@
 
 // CUR_SENS
 #ifndef USE_ADC_2
-#define USE_ADC_2 2
+#define USE_ADC_2 1
 #endif
 #if USE_ADC_2
 #define AD1_2_CHANNEL ADC_CHANNEL_IN3
@@ -84,6 +84,17 @@
 #define ADC_3_GPIO_PIN GPIO4
 #endif
 
+//ADC_pin_RSSI_IN
+#ifndef USE_ADC_4
+#define USE_ADC_4 1
+#endif
+#if USE_ADC_4
+#define AD1_4_CHANNEL ADC_CHANNEL_IN11
+#define ADC_4 AD1_4
+#define ADC_4_GPIO_PORT GPIOC
+#define ADC_4_GPIO_PIN GPIO1
+#endif
+
 /* allow to define ADC_CHANNEL_VSUPPLY in the airframe file*/
 #ifndef ADC_CHANNEL_VSUPPLY
 #define ADC_CHANNEL_VSUPPLY ADC_1
@@ -94,6 +105,11 @@
 #define ADC_CHANNEL_CURRENT ADC_2
 #endif
 
+#ifndef ADC_CHANNEL_RSSI
+#define ADC_CHANNEL_RSSI ADC_4
+#endif
+
+
 /* Default powerbrick values */
 #define DefaultVoltageOfAdc(adc) ((3.3f/4096.0f) * 10.27708149f * adc)
 #define DefaultMilliAmpereOfAdc(adc) ((3.3f/4096.0f) * 36367.51556f * adc)