AP_BattMonitor: add cycle count for smbus batteries

libraries/AP_BattMonitor/AP_BattMonitor.cpp

@@ -446,6 +446,15 @@ bool AP_BattMonitor::get_temperature(float &temperature, const uint8_t instance)
     }
 }
 
+// return true if cycle count can be provided and fills in cycles argument
+bool AP_BattMonitor::get_cycle_count(uint8_t instance, uint16_t &cycles) const
+{
+    if (instance >= AP_BATT_MONITOR_MAX_INSTANCES || (drivers[instance] == nullptr)) {
+        return false;
+    }
+    return drivers[instance]->get_cycle_count(cycles);
+}
+
 bool AP_BattMonitor::arming_checks(size_t buflen, char *buffer) const
 {
     char temp_buffer[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN+1] {};

libraries/AP_BattMonitor/AP_BattMonitor.h

@@ -152,9 +152,12 @@ public:
     const cells & get_cell_voltages(const uint8_t instance) const;
 
     // temperature
-    bool get_temperature(float &temperature) const { return get_temperature(temperature, AP_BATT_PRIMARY_INSTANCE); };
+    bool get_temperature(float &temperature) const { return get_temperature(temperature, AP_BATT_PRIMARY_INSTANCE); }
     bool get_temperature(float &temperature, const uint8_t instance) const;
 
+    // cycle count
+    bool get_cycle_count(uint8_t instance, uint16_t &cycles) const;
+
     // get battery resistance estimate in ohms
     float get_resistance() const { return get_resistance(AP_BATT_PRIMARY_INSTANCE); }
     float get_resistance(uint8_t instance) const { return state[instance].resistance; }

libraries/AP_BattMonitor/AP_BattMonitor_Backend.h

@@ -46,6 +46,9 @@ public:
     /// capacity_remaining_pct - returns the % battery capacity remaining (0 ~ 100)
     uint8_t capacity_remaining_pct() const;
 
+    // return true if cycle count can be provided and fills in cycles argument
+    virtual bool get_cycle_count(uint16_t &cycles) const { return false; }
+
     /// get voltage with sag removed (based on battery current draw and resistance)
     /// this will always be greater than or equal to the raw voltage
     float voltage_resting_estimate() const;

libraries/AP_BattMonitor/AP_BattMonitor_SMBus.cpp

@@ -13,12 +13,23 @@ AP_BattMonitor_SMBus::AP_BattMonitor_SMBus(AP_BattMonitor &mon,
     _params._pack_capacity = 0;
 }
 
-void AP_BattMonitor_SMBus::init(void) {
+void AP_BattMonitor_SMBus::init(void)
+{
     if (_dev) {
         _dev->register_periodic_callback(100000, FUNCTOR_BIND_MEMBER(&AP_BattMonitor_SMBus::timer, void));
     }
 }
 
+// return true if cycle count can be provided and fills in cycles argument
+bool AP_BattMonitor_SMBus::get_cycle_count(uint16_t &cycles) const
+{
+    if (!_has_cycle_count) {
+        return false;
+    }
+    cycles = _cycle_count;
+    return true;
+}
+
 /// read the battery_voltage and current, should be called at 10hz
 void AP_BattMonitor_SMBus::read(void)
 {
@@ -83,7 +94,8 @@ bool AP_BattMonitor_SMBus::read_temp(void)
 
 // reads the serial number if it's not already known
 // returns true if the read was successful or the number was already known
-bool AP_BattMonitor_SMBus::read_serial_number(void) {
+bool AP_BattMonitor_SMBus::read_serial_number(void)
+{
     uint16_t data;
 
     // don't recheck the serial number if we already have it
@@ -97,6 +109,16 @@ bool AP_BattMonitor_SMBus::read_serial_number(void) {
     return false;
 }
 
+// reads the battery's cycle count
+void AP_BattMonitor_SMBus::read_cycle_count()
+{
+    // only read cycle count once
+    if (_has_cycle_count) {
+        return;
+    }
+    _has_cycle_count = read_word(BATTMONITOR_SMBUS_CYCLE_COUNT, _cycle_count);
+}
+
 // read word from register
 // returns true if read was successful, false if failed
 bool AP_BattMonitor_SMBus::read_word(uint8_t reg, uint16_t& data) const

libraries/AP_BattMonitor/AP_BattMonitor_SMBus.h

@@ -22,6 +22,7 @@ public:
         BATTMONITOR_SMBUS_CURRENT = 0x0A,              // Current
         BATTMONITOR_SMBUS_REMAINING_CAPACITY = 0x0F,   // Remaining Capacity
         BATTMONITOR_SMBUS_FULL_CHARGE_CAPACITY = 0x10, // Full Charge Capacity
+        BATTMONITOR_SMBUS_CYCLE_COUNT = 0x17,          // Cycle Count
         BATTMONITOR_SMBUS_SPECIFICATION_INFO = 0x1A,   // Specification Info
         BATTMONITOR_SMBUS_SERIAL = 0x1C,               // Serial Number
         BATTMONITOR_SMBUS_MANUFACTURE_NAME = 0x20,     // Manufacture Name
@@ -45,6 +46,9 @@ public:
     // don't allow reset of remaining capacity for SMBus
     bool reset_remaining(float percentage) override { return false; }
 
+    // return true if cycle count can be provided and fills in cycles argument
+    bool get_cycle_count(uint16_t &cycles) const override;
+
     void init(void) override;
 
 protected:
@@ -68,6 +72,9 @@ protected:
     // returns true if the read was successful, or the number was already known
     bool read_serial_number(void);
 
+    // reads the battery's cycle count
+    void read_cycle_count();
+
      // read word from register
      // returns true if read was successful, false if failed
     bool read_word(uint8_t reg, uint16_t& data) const;
@@ -81,8 +88,9 @@ protected:
 
     int32_t _serial_number = -1;    // battery serial number
     uint16_t _full_charge_capacity; // full charge capacity, used to stash the value before setting the parameter
-
+    bool _has_cell_voltages;        // smbus backends flag this as true once they have received a valid cell voltage report
-    bool _has_cell_voltages;        // smbus backends flag this as true once they have recieved a valid cell voltage report
+    uint16_t _cycle_count = 0;      // number of cycles the battery has experienced. An amount of discharge approximately equal to the value of DesignCapacity.
+    bool _has_cycle_count;          // true if cycle count has been retrieved from the battery
 
     virtual void timer(void) = 0;   // timer function to read from the battery
 

libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Maxell.cpp

@@ -85,6 +85,8 @@ void AP_BattMonitor_SMBus_Maxell::timer()
     read_temp();
 
     read_serial_number();
+
+    read_cycle_count();
 }
 
 // read_block - returns number of characters read if successful, zero if unsuccessful

libraries/AP_BattMonitor/AP_BattMonitor_SMBus_Solo.cpp

@@ -93,6 +93,8 @@ void AP_BattMonitor_SMBus_Solo::timer()
     read_temp();
 
     read_serial_number();
+
+    read_cycle_count();
 }
 
 // read_block - returns number of characters read if successful, zero if unsuccessful