Added RSSI feedback and analog input for A1 / A2 to FrSky D SPI RX.

src/main/fc/fc_init.c

@@ -81,6 +81,7 @@
 #include "msp/msp_serial.h"
 
 #include "rx/rx.h"
+#include "rx/rx_spi.h"
 #include "rx/spektrum.h"
 
 #include "io/beeper.h"
@@ -495,7 +496,8 @@ void init(void)
     adcConfigMutable()->vbat.enabled = (batteryConfig()->voltageMeterSource == VOLTAGE_METER_ADC);
     adcConfigMutable()->current.enabled = (batteryConfig()->currentMeterSource == CURRENT_METER_ADC);
 
-    adcConfigMutable()->rssi.enabled = feature(FEATURE_RSSI_ADC);
+    // The FrSky D SPI RX sends RSSI_ADC_PIN (if configured) as A2
+    adcConfigMutable()->rssi.enabled = feature(FEATURE_RSSI_ADC) || (feature(FEATURE_RX_SPI) && rxConfig()->rx_spi_protocol == RX_SPI_FRSKY_D);
     adcInit(adcConfig());
 #endif
 

src/main/rx/frsky_d.c

@@ -27,6 +27,7 @@
 #include "build/build_config.h"
 
 #include "common/utils.h"
+#include "common/maths.h"
 
 #include "drivers/cc2500.h"
 #include "drivers/io.h"
@@ -128,8 +129,6 @@ static uint8_t frame[20];
 static int16_t RSSI_dBm;
 static uint8_t telemetry_id;
 static uint8_t telemetryRX;
-static uint8_t v1; // A1
-static uint8_t v2; // A2
 static uint32_t telemetryTime;
 
 #if defined(HUB)
@@ -178,6 +177,8 @@ static void compute_RSSIdbm(uint8_t *packet)
     } else {
         RSSI_dBm = ((((uint16_t)packet[ccLen - 2]) * 18) >> 5) + 65;
     }
+
+    processRssi(constrain((RSSI_dBm << 3) / 10, 0, 100));
 }
 
 #if defined(HUB)
@@ -217,14 +218,15 @@ static void frSkyTelemetryWriteSpi(uint8_t ch)
 
 static void telemetry_build_frame(uint8_t *packet)
 {
-    v1 = 0;
+    const uint16_t adcExternal1Sample = adcGetChannel(ADC_EXTERNAL1);
+    const uint16_t adcRssiSample = adcGetChannel(ADC_RSSI);
     uint8_t bytes_used = 0;
     telemetry_id = packet[4];
     frame[0] = 0x11; // length
     frame[1] = frSkyDConfig()->bindTxId[0];
     frame[2] = frSkyDConfig()->bindTxId[1];
-    frame[3] = v1; // A1 voltages
+    frame[3] = (uint8_t)((adcExternal1Sample & 0xff0) >> 4); // A1
-    frame[4] = v2; // A2
+    frame[4] = (uint8_t)((adcRssiSample & 0xff0) >> 4);      // A2
     frame[5] = (uint8_t)RSSI_dBm;
 #if defined(HUB)
     bytes_used = frsky_append_hub_data(&frame[8]);

src/main/rx/rx.c

@@ -616,15 +616,11 @@ static void updateRSSIPWM(void)
     rssi = (uint16_t)((constrain(pwmRssi - 1000, 0, 1000) / 1000.0f) * 1023.0f);
 }
 
-#define RSSI_ADC_SAMPLE_COUNT 16
-
 static void updateRSSIADC(timeUs_t currentTimeUs)
 {
 #ifndef USE_ADC
     UNUSED(currentTimeUs);
 #else
-    static uint8_t adcRssiSamples[RSSI_ADC_SAMPLE_COUNT];
-    static uint8_t adcRssiSampleIndex = 0;
     static uint32_t rssiUpdateAt = 0;
 
     if ((int32_t)(currentTimeUs - rssiUpdateAt) < 0) {
@@ -635,26 +631,36 @@ static void updateRSSIADC(timeUs_t currentTimeUs)
     const uint16_t adcRssiSample = adcGetChannel(ADC_RSSI);
     const uint8_t rssiPercentage = adcRssiSample / rxConfig()->rssi_scale;
 
-    adcRssiSampleIndex = (adcRssiSampleIndex + 1) % RSSI_ADC_SAMPLE_COUNT;
+    processRssi(rssiPercentage);
+#endif
+}
 
-    adcRssiSamples[adcRssiSampleIndex] = rssiPercentage;
+#define RSSI_SAMPLE_COUNT 16
 
-    int16_t adcRssiMean = 0;
+void processRssi(uint8_t rssiPercentage)
-    for (int sampleIndex = 0; sampleIndex < RSSI_ADC_SAMPLE_COUNT; sampleIndex++) {
+{
-        adcRssiMean += adcRssiSamples[sampleIndex];
+    static uint8_t rssiSamples[RSSI_SAMPLE_COUNT];
+    static uint8_t rssiSampleIndex = 0;
+
+    rssiSampleIndex = (rssiSampleIndex + 1) % RSSI_SAMPLE_COUNT;
+
+    rssiSamples[rssiSampleIndex] = rssiPercentage;
+
+    int16_t rssiMean = 0;
+    for (int sampleIndex = 0; sampleIndex < RSSI_SAMPLE_COUNT; sampleIndex++) {
+        rssiMean += rssiSamples[sampleIndex];
     }
 
-    adcRssiMean = adcRssiMean / RSSI_ADC_SAMPLE_COUNT;
+    rssiMean = rssiMean / RSSI_SAMPLE_COUNT;
 
-    adcRssiMean=constrain(adcRssiMean, 0, 100);
+    rssiMean=constrain(rssiMean, 0, 100);
 
     // RSSI_Invert option
     if (rxConfig()->rssi_invert) {
-        adcRssiMean = 100 - adcRssiMean;
+        rssiMean = 100 - rssiMean;
     }
 
-    rssi = (uint16_t)((adcRssiMean / 100.0f) * 1023.0f);
+    rssi = (uint16_t)((rssiMean / 100.0f) * 1023.0f);
-#endif
 }
 
 void updateRSSI(timeUs_t currentTimeUs)

src/main/rx/rx.h

@@ -168,6 +168,8 @@ void calculateRxChannelsAndUpdateFailsafe(timeUs_t currentTimeUs);
 void parseRcChannels(const char *input, rxConfig_t *rxConfig);
 
 void updateRSSI(timeUs_t currentTimeUs);
+void processRssi(uint8_t rssiPercentage);
+
 void resetAllRxChannelRangeConfigurations(rxChannelRangeConfig_t *rxChannelRangeConfig);
 
 void suspendRxSignal(void);

src/main/target/MIDELICF3/target.h

@@ -87,6 +87,11 @@
 #define ADC_INSTANCE            ADC1
 #define VBAT_ADC_PIN            PA0
 #define CURRENT_METER_ADC_PIN   PA1
+
+// Can be used on motor 1 / 2 pads (A02 / A03):
+#define EXTERNAL1_ADC_PIN       NONE
+#define RSSI_ADC_PIN            NONE
+
 #define DEFAULT_VOLTAGE_METER_SOURCE VOLTAGE_METER_ADC
 #define DEFAULT_CURRENT_METER_SOURCE CURRENT_METER_ADC