Fixes to RX/RC mode handling code

src/main/fc/rc_controls.c

@@ -63,7 +63,7 @@
 
 #define AIRMODE_DEADBAND 25
 #define MIN_RC_TICK_INTERVAL_MS 20
-#define DEFAULT_RC_SWITCH_DISARM_DELAY_MS 150 // Wait at least 150ms before disarming via switch
+#define DEFAULT_RC_SWITCH_DISARM_DELAY_MS 250 // Wait at least 250ms before disarming via switch
 
 stickPositions_e rcStickPositions;
 

src/main/fc/rc_modes.c

@@ -129,15 +129,24 @@ void updateActivatedModes(void)
  // For AND logic, the specified condition count and valid condition count must be the same.
  // For OR logic, the valid condition count must be greater than zero.
 
- if (modeActivationOperatorConfig()->modeActivationOperator == MODE_OPERATOR_AND) {
- // AND the conditions
- if (activeConditionCountPerMode[modeIndex] == specifiedConditionCountPerMode[modeIndex]) {
- bitArraySet(newMask.bits, modeIndex);
+ // Prohibit BOX mode change alltogether if RX link is not stable enough
+ if (rxIsSignalStable() || modeIndex == BOXFAILSAFE) {
+ if (modeActivationOperatorConfig()->modeActivationOperator == MODE_OPERATOR_AND) {
+ // AND the conditions
+ if (activeConditionCountPerMode[modeIndex] == specifiedConditionCountPerMode[modeIndex]) {
+ bitArraySet(newMask.bits, modeIndex);
+ }
+ }
+ else {
+ // OR the conditions
+ if (activeConditionCountPerMode[modeIndex] > 0) {
+ bitArraySet(newMask.bits, modeIndex);
+ }
  }
  }
  else {
- // OR the conditions
- if (activeConditionCountPerMode[modeIndex] > 0) {
+ // Retail current mode state
+ if (bitArrayGet(rcModeActivationMask.bits, modeIndex)) {
  bitArraySet(newMask.bits, modeIndex);
  }
  }

src/main/rx/rx.c

@@ -79,6 +79,7 @@ static rssiSource_e rssiSource;
 static bool rxDataProcessingRequired = false;
 static bool auxiliaryProcessingRequired = false;
 
+static uint32_t rxValidFramesCount = 0;
 static bool rxSignalReceived = false;
 static bool rxFlightChannelsValid = false;
 static bool rxIsInFailsafeMode = true;
@@ -92,7 +93,8 @@ int16_t rcRaw[MAX_SUPPORTED_RC_CHANNEL_COUNT]; // interval [1000;2000]
 int16_t rcData[MAX_SUPPORTED_RC_CHANNEL_COUNT]; // interval [1000;2000]
 uint32_t rcInvalidPulsPeriod[MAX_SUPPORTED_RC_CHANNEL_COUNT];
 
-#define MAX_INVALID_PULS_TIME 300
+#define FILTERING_SAMPLE_COUNT 5
+#define MAX_INVALID_PULS_TIME 300
 
 #define SKIP_RC_ON_SUSPEND_PERIOD 1500000 // 1.5 second period in usec (call frequency independent)
 #define SKIP_RC_SAMPLES_ON_RESUME 2 // flush 2 samples to drop wrong measurements (timing independent)
@@ -364,6 +366,12 @@ bool rxIsReceivingSignal(void)
  return rxSignalReceived;
 }
 
+bool rxIsSignalStable(void)
+{
+ // Filtering may delay the channel values up to FILTERING_SAMPLE_COUNT in worst case
+ return rxIsReceivingSignal() && (rxValidFramesCount >= (rxRuntimeConfig.requireFiltering ? FILTERING_SAMPLE_COUNT : 1));
+}
+
 bool rxAreFlightChannelsValid(void)
 {
  return rxFlightChannelsValid;
@@ -432,7 +440,6 @@ bool rxUpdateCheck(timeUs_t currentTimeUs, timeDelta_t currentDeltaTime)
  return rxDataProcessingRequired || auxiliaryProcessingRequired; // data driven or 50Hz
 }
 
-#define FILTERING_SAMPLE_COUNT 5
 static uint16_t applyChannelFiltering(uint8_t chan, uint16_t sample)
 {
  static int16_t rcSamples[MAX_SUPPORTED_RC_CHANNEL_COUNT][FILTERING_SAMPLE_COUNT];
@@ -482,6 +489,15 @@ void calculateRxChannelsAndUpdateFailsafe(timeUs_t currentTimeUs)
  rxDataProcessingRequired = false;
  rxNextUpdateAtUs = currentTimeUs + DELAY_50_HZ;
 
+ // We got here, that means we have received a valid frame (or a frame timeout)
+ // If we are receiving signal increase valid frame count (used as a consistency measurement)
+ if (rxSignalReceived) {
+ rxValidFramesCount++;
+ }
+ else {
+ rxValidFramesCount = 0;
+ }
+
  // only proceed when no more samples to skip and suspend period is over
  if (skipRxSamples) {
  if (currentTimeUs > suspendRxSignalUntil) {
@@ -492,7 +508,7 @@ void calculateRxChannelsAndUpdateFailsafe(timeUs_t currentTimeUs)
  }
 
  rxFlightChannelsValid = true;
- 
+
  // Read and process channel data
  for (int channel = 0; channel < rxRuntimeConfig.channelCount; channel++) {
  const uint8_t rawChannel = calculateChannelRemapping(rxConfig()->rcmap, REMAPPABLE_CHANNEL_COUNT, channel);

src/main/rx/rx.h

@@ -163,6 +163,7 @@ extern rxRuntimeConfig_t rxRuntimeConfig; //!!TODO remove this extern, only need
 void rxInit(void);
 void rxUpdateRSSISource(void);
 bool rxUpdateCheck(timeUs_t currentTimeUs, timeDelta_t currentDeltaTime);
+bool rxIsSignalStable(void);
 bool rxIsReceivingSignal(void);
 bool rxAreFlightChannelsValid(void);
 void calculateRxChannelsAndUpdateFailsafe(timeUs_t currentTimeUs);