feat(zigbee): Add battery voltage attribute support

libraries/Zigbee/examples/Zigbee_Temp_Hum_Sensor_Sleepy/Zigbee_Temp_Hum_Sensor_Sleepy.ino

@@ -85,9 +85,9 @@ void setup() {
   // Set tolerance for temperature measurement in °C (lowest possible value is 0.01°C)
   zbTempSensor.setTolerance(1);
 
-  // Set power source to battery and set battery percentage to measured value (now 100% for demonstration)
-  // The value can be also updated by calling zbTempSensor.setBatteryPercentage(percentage) anytime
-  zbTempSensor.setPowerSource(ZB_POWER_SOURCE_BATTERY, 100);
+  // Set power source to battery, battery percentage and battery voltage (now 100% and 3.5V for demonstration)
+  // The value can be also updated by calling zbTempSensor.setBatteryPercentage(percentage) or zbTempSensor.setBatteryVoltage(voltage) anytime after Zigbee.begin()
+  zbTempSensor.setPowerSource(ZB_POWER_SOURCE_BATTERY, 100, 35);
 
   // Add humidity cluster to the temperature sensor device with min, max and tolerance values
   zbTempSensor.addHumiditySensor(0, 100, 1);

libraries/Zigbee/src/ZigbeeEP.cpp

@@ -68,7 +68,7 @@ bool ZigbeeEP::setManufacturerAndModel(const char *name, const char *model) {
   return ret_name == ESP_OK && ret_model == ESP_OK;
 }
 
-bool ZigbeeEP::setPowerSource(zb_power_source_t power_source, uint8_t battery_percentage) {
+bool ZigbeeEP::setPowerSource(zb_power_source_t power_source, uint8_t battery_percentage, uint8_t battery_voltage) {
   esp_zb_attribute_list_t *basic_cluster = esp_zb_cluster_list_get_cluster(_cluster_list, ESP_ZB_ZCL_CLUSTER_ID_BASIC, ESP_ZB_ZCL_CLUSTER_SERVER_ROLE);
   esp_err_t ret = esp_zb_cluster_update_attr(basic_cluster, ESP_ZB_ZCL_ATTR_BASIC_POWER_SOURCE_ID, (void *)&power_source);
   if (ret != ESP_OK) {
@@ -88,6 +88,11 @@ bool ZigbeeEP::setPowerSource(zb_power_source_t power_source, uint8_t battery_pe
       log_e("Failed to add battery percentage attribute: 0x%x: %s", ret, esp_err_to_name(ret));
       return false;
     }
+    ret = esp_zb_power_config_cluster_add_attr(power_config_cluster, ESP_ZB_ZCL_ATTR_POWER_CONFIG_BATTERY_VOLTAGE_ID, (void *)&battery_voltage);
+    if (ret != ESP_OK) {
+      log_e("Failed to add battery voltage attribute: 0x%x: %s", ret, esp_err_to_name(ret));
+      return false;
+    }
     ret = esp_zb_cluster_list_add_power_config_cluster(_cluster_list, power_config_cluster, ESP_ZB_ZCL_CLUSTER_SERVER_ROLE);
     if (ret != ESP_OK) {
       log_e("Failed to add power config cluster: 0x%x: %s", ret, esp_err_to_name(ret));
@@ -120,6 +125,21 @@ bool ZigbeeEP::setBatteryPercentage(uint8_t percentage) {
   return true;
 }
 
+bool ZigbeeEP::setBatteryVoltage(uint8_t voltage) {
+  esp_zb_zcl_status_t ret = ESP_ZB_ZCL_STATUS_SUCCESS;
+  esp_zb_lock_acquire(portMAX_DELAY);
+  ret = esp_zb_zcl_set_attribute_val(
+    _endpoint, ESP_ZB_ZCL_CLUSTER_ID_POWER_CONFIG, ESP_ZB_ZCL_CLUSTER_SERVER_ROLE, ESP_ZB_ZCL_ATTR_POWER_CONFIG_BATTERY_VOLTAGE_ID, &voltage, false
+  );
+  esp_zb_lock_release();
+  if (ret != ESP_ZB_ZCL_STATUS_SUCCESS) {
+    log_e("Failed to set battery voltage: 0x%x: %s", ret, esp_zb_zcl_status_to_name(ret));
+    return false;
+  }
+  log_v("Battery voltage updated");
+  return true;
+}
+
 bool ZigbeeEP::reportBatteryPercentage() {
   /* Send report attributes command */
   esp_zb_zcl_report_attr_cmd_t report_attr_cmd;

libraries/Zigbee/src/ZigbeeEP.h

@@ -77,9 +77,10 @@ class ZigbeeEP {
   char *readModel(uint8_t endpoint, uint16_t short_addr, esp_zb_ieee_addr_t ieee_addr);
 
   // Set Power source and battery percentage for battery powered devices
-  bool setPowerSource(zb_power_source_t power_source, uint8_t percentage = 255);
-  bool setBatteryPercentage(uint8_t percentage);
-  bool reportBatteryPercentage();
+  bool setPowerSource(zb_power_source_t power_source, uint8_t percentage = 0xff, uint8_t voltage = 0xff);  // voltage in 100mV
+  bool setBatteryPercentage(uint8_t percentage);                                                           // 0-100 %
+  bool setBatteryVoltage(uint8_t voltage);                                                                 // voltage in 100mV (example value 35 for 3.5V)
+  bool reportBatteryPercentage();                                                                          // battery voltage is not reportable attribute
 
   // Set time
   bool addTimeCluster(tm time = {}, int32_t gmt_offset = 0);  // gmt offset in seconds