AP_BattMonitor: UAVCAN: allow battery reset if not using CAN SoC

libraries/AP_BattMonitor/AP_BattMonitor_UAVCAN.cpp

@@ -295,15 +295,22 @@ void AP_BattMonitor_UAVCAN::read()
     }
 }
 
+// Return true if the DroneCAN state of charge should be used.
+// Return false if state of charge should be calculated locally by counting mah.
+bool AP_BattMonitor_UAVCAN::use_CAN_SoC() const
+{
+    // a UAVCAN battery monitor may not be able to supply a state of charge. If it can't then
+    // the user can set the option to use current integration in the backend instead.
+    // SOC of 127 is used as an invalid SOC flag ie system configuration errors or SOC estimation unavailable
+    return !(option_is_set(AP_BattMonitor_Params::Options::Ignore_UAVCAN_SoC) ||
+            _mppt.is_detected ||
+            (_soc == 127));
+}
+
 /// capacity_remaining_pct - returns true if the percentage is valid and writes to percentage argument
 bool AP_BattMonitor_UAVCAN::capacity_remaining_pct(uint8_t &percentage) const
 {
-    if ((uint32_t(_params._options.get()) & uint32_t(AP_BattMonitor_Params::Options::Ignore_UAVCAN_SoC)) ||
-        _mppt.is_detected ||
-        _soc == 127) {
-        // a UAVCAN battery monitor may not be able to supply a state of charge. If it can't then
-        // the user can set the option to use current integration in the backend instead.
-        // SOC of 127 is used as an invalid SOC flag ie system configuration errors or SOC estimation unavailable
+    if (!use_CAN_SoC()) {
         return AP_BattMonitor_Backend::capacity_remaining_pct(percentage);
     }
 
@@ -316,6 +323,27 @@ bool AP_BattMonitor_UAVCAN::capacity_remaining_pct(uint8_t &percentage) const
     return true;
 }
 
+// reset remaining percentage to given value
+bool AP_BattMonitor_UAVCAN::reset_remaining(float percentage)
+{
+    if (use_CAN_SoC()) {
+        // Cannot reset external state of charge
+        return false;
+    }
+
+    WITH_SEMAPHORE(_sem_battmon);
+
+    if (!AP_BattMonitor_Backend::reset_remaining(percentage)) {
+        // Base class reset failed
+        return false;
+    }
+
+    // Reset interim state that is used internally, this is then copied back to the main state in the read() call
+    _interim_state.consumed_mah = _state.consumed_mah;
+    _interim_state.consumed_wh = _state.consumed_wh;
+    return true;
+}
+
 /// get_cycle_count - return true if cycle count can be provided and fills in cycles argument
 bool AP_BattMonitor_UAVCAN::get_cycle_count(uint16_t &cycles) const
 {

libraries/AP_BattMonitor/AP_BattMonitor_UAVCAN.h

@@ -60,6 +60,9 @@ public:
 
     void mppt_set_powered_state(bool power_on) override;
 
+    // reset remaining percentage to given value
+    bool reset_remaining(float percentage) override;
+
 private:
     void handle_battery_info(const BattInfoCb &cb);
     void handle_battery_info_aux(const BattInfoAuxCb &cb);
@@ -85,6 +88,10 @@ private:
     static const char* mppt_fault_string(const MPPT_FaultFlags fault);
 #endif
 
+    // Return true if the DroneCAN state of charge should be used.
+    // Return false if state of charge should be calculated locally by counting mah.
+    bool use_CAN_SoC() const;
+
     AP_BattMonitor::BattMonitor_State _interim_state;
     BattMonitor_UAVCAN_Type _type;