Voltage detection method (#13350)

change voltage detection method and is voltage stable flag to make it resilient and synced to update battery task Co-authored-by: Eike Ahmels <ea@weslink.de>
betaflight · Feb 6, 2024 · 744ab45 · 744ab45
1 parent 24e7dab
commit 744ab45
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Showing 4 changed files with 29 additions and 13 deletions.
diff --git a/src/main/sensors/battery.c b/src/main/sensors/battery.c
@@ -67,7 +67,7 @@
  *
  */
 
-#define VBAT_STABLE_MAX_DELTA 20
+#define VBAT_STABLE_MAX_DELTA 10 // 100mV
 #define LVC_AFFECT_TIME 10000000 //10 secs for the LVC to slowly kick in
 
 // Battery monitoring stuff
@@ -159,8 +159,21 @@ void batteryUpdateVoltage(timeUs_t currentTimeUs)
             break;
     }
 
+    if (!voltageMeter.isVoltageStable && cmp32(millis(), voltageMeter.prevDisplayFilteredTime) >= PREV_DISPLAY_FILTERED_TIME_DIFF) {
+        if ((voltageState == BATTERY_NOT_PRESENT || voltageState == BATTERY_INIT) && isVoltageFromBattery()) {
+            voltageMeter.isVoltageStable = abs(voltageMeter.prevDisplayFiltered - voltageMeter.displayFiltered) <= VBAT_STABLE_MAX_DELTA;
+        }
+
+        voltageMeter.prevDisplayFiltered = voltageMeter.displayFiltered;
+        voltageMeter.prevDisplayFilteredTime = millis();
+    }
+
     DEBUG_SET(DEBUG_BATTERY, 0, voltageMeter.unfiltered);
     DEBUG_SET(DEBUG_BATTERY, 1, voltageMeter.displayFiltered);
+    DEBUG_SET(DEBUG_BATTERY, 4, voltageMeter.isVoltageStable ? 1 : 0);
+    DEBUG_SET(DEBUG_BATTERY, 5, isVoltageFromBattery() ? 1 : 0);
+    DEBUG_SET(DEBUG_BATTERY, 6, voltageMeter.prevDisplayFiltered);
+    DEBUG_SET(DEBUG_BATTERY, 7, voltageState);
 }
 
 static void updateBatteryBeeperAlert(void)
@@ -181,14 +194,7 @@ static void updateBatteryBeeperAlert(void)
     }
 }
 
-//TODO: make all of these independent of voltage filtering for display
-
-static bool isVoltageStable(void)
-{
-    return abs(voltageMeter.displayFiltered - voltageMeter.unfiltered) <= VBAT_STABLE_MAX_DELTA;
-}
-
-static bool isVoltageFromBat(void)
+bool isVoltageFromBattery(void)
 {
     // We want to disable battery getting detected around USB voltage or 0V
 
@@ -199,7 +205,7 @@ static bool isVoltageFromBat(void)
 
 void batteryUpdatePresence(void)
 {
-    if ((voltageState == BATTERY_NOT_PRESENT || voltageState == BATTERY_INIT) && isVoltageFromBat() && isVoltageStable()) {
+    if ((voltageState == BATTERY_NOT_PRESENT || voltageState == BATTERY_INIT) && isVoltageFromBattery() && voltageMeter.isVoltageStable) {
         // Battery has just been connected - calculate cells, warning voltages and reset state
 
         consumptionState = voltageState = BATTERY_OK;
@@ -226,11 +232,11 @@ void batteryUpdatePresence(void)
         batteryCriticalHysteresisVoltage = (batteryCriticalVoltage > batteryConfig()->vbathysteresis) ? batteryCriticalVoltage - batteryConfig()->vbathysteresis : 0;
         lowVoltageCutoff.percentage = 100;
         lowVoltageCutoff.startTime = 0;
-    } else if (voltageState != BATTERY_NOT_PRESENT && isVoltageStable() && !isVoltageFromBat()) {
+    } else if (voltageState != BATTERY_NOT_PRESENT && voltageMeter.isVoltageStable && !isVoltageFromBattery()) {
         /* battery has been disconnected - can take a while for filter cap to disharge so we use a threshold of batteryConfig()->vbatnotpresentcellvoltage */
-
         consumptionState = voltageState = BATTERY_NOT_PRESENT;
-
+
+        voltageMeter.isVoltageStable = false;
         batteryCellCount = 0;
         batteryWarningVoltage = 0;
         batteryCriticalVoltage = 0;

diff --git a/src/main/sensors/battery.h b/src/main/sensors/battery.h
@@ -97,6 +97,8 @@ void batteryInit(void);
 void batteryUpdateVoltage(timeUs_t currentTimeUs);
 void batteryUpdatePresence(void);
 
+bool isVoltageFromBattery(void);
+
 batteryState_e getBatteryState(void);
 batteryState_e getVoltageState(void);
 batteryState_e getConsumptionState(void);

diff --git a/src/main/sensors/voltage.c b/src/main/sensors/voltage.c
@@ -89,7 +89,10 @@ const uint8_t supportedVoltageMeterCount = ARRAYLEN(voltageMeterIds);
 void voltageMeterReset(voltageMeter_t *meter)
 {
     meter->displayFiltered = 0;
+    meter->prevDisplayFiltered = 0;
+    meter->prevDisplayFilteredTime = 0;
     meter->unfiltered = 0;
+    meter->isVoltageStable = false;
 #if defined(USE_BATTERY_VOLTAGE_SAG_COMPENSATION)
     meter->sagFiltered = 0;
 #endif

diff --git a/src/main/sensors/voltage.h b/src/main/sensors/voltage.h
@@ -25,6 +25,8 @@
 #define SLOW_VOLTAGE_TASK_FREQ_HZ 50
 #define FAST_VOLTAGE_TASK_FREQ_HZ 200
 
+#define PREV_DISPLAY_FILTERED_TIME_DIFF 500 // ms
+
 //
 // meters
 //
@@ -42,6 +44,9 @@ extern const char * const voltageMeterSourceNames[VOLTAGE_METER_COUNT];
 
 typedef struct voltageMeter_s {
     uint16_t displayFiltered;               // voltage in 0.01V steps
+    uint16_t prevDisplayFiltered;               // voltage in 0.01V steps
+    timeMs_t prevDisplayFilteredTime;
+    bool isVoltageStable;
     uint16_t unfiltered;                    // voltage in 0.01V steps
 #if defined(USE_BATTERY_VOLTAGE_SAG_COMPENSATION)
     uint16_t sagFiltered;                   // voltage in 0.01V steps