Merge pull request #6875 from kivaisan/fix_batterylevel_callback_v2

Lora: Fix battery_level callback

Author: Cruz Monrreal

features/lorawan/LoRaWANStack.cpp

@@ -134,6 +134,7 @@ lorawan_status_t LoRaWANStack::set_lora_callbacks(const lorawan_app_callbacks_t
 
     if (callbacks->battery_level) {
         _callbacks.battery_level = callbacks->battery_level;
+        _loramac.set_batterylevel_callback(callbacks->battery_level);
     }
 
     return LORAWAN_STATUS_OK;

features/lorawan/lorastack/mac/LoRaMac.cpp

@@ -661,6 +661,11 @@ void LoRaMac::handle_data_frame(const uint8_t* const payload,
                                  _params.ack_timeout_retry_counter, _params.max_ack_timeout_retries );
 }
 
+void LoRaMac::set_batterylevel_callback(mbed::Callback<uint8_t(void)> battery_level)
+{
+    _mac_commands.set_batterylevel_callback(battery_level);
+}
+
 void LoRaMac::on_radio_rx_done(const uint8_t* const payload, uint16_t size,
                                int16_t rssi, int8_t snr)
 {

features/lorawan/lorastack/mac/LoRaMac.h

@@ -437,6 +437,11 @@ class LoRaMac {
     void post_process_mlme_request(void);
     void post_process_mlme_ind(void);
 
+    /**
+     * Set battery level query callback
+     */
+    void set_batterylevel_callback(mbed::Callback<uint8_t(void)> battery_level);
+
     /**
      * These locks trample through to the upper layers and make
      * the stack thread safe.

features/lorawan/lorastack/mac/LoRaMacCommand.cpp

@@ -233,10 +233,11 @@ lorawan_status_t LoRaMacCommand::process_mac_commands(const uint8_t *payload, ui
             }
                 break;
             case SRV_MAC_DEV_STATUS_REQ: {
-                uint8_t batteryLevel = BAT_LEVEL_NO_MEASURE;
-                // we don't have a mechanism at the moment to measure
-                // battery levels
-                ret_value = add_dev_status_ans(batteryLevel, snr & 0x3F);
+                uint8_t battery_level = BAT_LEVEL_NO_MEASURE;
+                if (_battery_level_cb) {
+                    battery_level = _battery_level_cb();
+                }
+                ret_value = add_dev_status_ans(battery_level, snr & 0x3F);
                 break;
             }
             case SRV_MAC_NEW_CHANNEL_REQ: {
@@ -329,6 +330,11 @@ int32_t LoRaMacCommand::cmd_buffer_remaining() const
     return sizeof(mac_cmd_buffer) - mac_cmd_buf_idx_to_repeat - mac_cmd_buf_idx;
 }
 
+void LoRaMacCommand::set_batterylevel_callback(mbed::Callback<uint8_t(void)> battery_level)
+{
+    _battery_level_cb = battery_level;
+}
+
 lorawan_status_t LoRaMacCommand::add_link_check_req()
 {
     lorawan_status_t ret = LORAWAN_STATUS_LENGTH_ERROR;

features/lorawan/lorastack/mac/LoRaMacCommand.h

@@ -147,6 +147,12 @@ class LoRaMacCommand {
      */
     lorawan_status_t add_link_check_req();
 
+    /**
+     * @brief Set battery level query callback method
+     *        If callback is not set, BAT_LEVEL_NO_MEASURE is returned.
+     */
+    void set_batterylevel_callback(mbed::Callback<uint8_t(void)> battery_level);
+
 private:
     /**
      * @brief Get the remaining size of the MAC command buffer
@@ -261,6 +267,8 @@ class LoRaMacCommand {
      * Buffer containing the MAC layer commands which must be repeated
      */
     uint8_t mac_cmd_buffer_to_repeat[LORA_MAC_COMMAND_MAX_LENGTH];
+
+    mbed::Callback<uint8_t(void)> _battery_level_cb;
 };
 
 #endif //__LORAMACCOMMAND_H__

features/lorawan/lorawan_types.h

@@ -274,8 +274,17 @@ typedef struct  {
       * Optional
       */
      mbed::Callback<void(uint8_t, uint8_t)> link_check_resp;
+
+     /**
+      * Battery level return value must follow the specification
+      * for DevStatusAns MAC command:
+      *
+      *     0       The end-device is connected to an external power source
+      *     1 - 254 The battery level, 1 being at minimum and 254 being at maximum
+      *     255     The end-device was not able to measure the battery level.
+      */
      mbed::Callback<uint8_t(void)> battery_level;
- } lorawan_app_callbacks_t;
+} lorawan_app_callbacks_t;
 
 /**
  * DO NOT MODIFY, WILL BREAK THE API!