Add battery stats (#800)

* Add battery stats

* Update emotibit.cpp

* Fix EmotiBit clang-format

---------

Co-authored-by: calebkuitenbrouwer <33358507+calebkuitenbrouwer@users.noreply.github.com>
Co-authored-by: Andrey Parfenov <a1994ndrey@gmail.com>

Author: 3 people

src/board_controller/brainflow_boards.cpp

@@ -896,10 +896,11 @@ BrainFlowBoards::BrainFlowBoards()
         {"package_num_channel", 0},
         {"timestamp_channel", 4},
         {"marker_channel", 5},
-        {"num_rows", 6},
+        {"num_rows", 8},
         {"eda_channels", {1}},
         {"temperature_channels", {2}},
-        {"other_channels", {3}}
+        {"other_channels", {3, 6}},
+        {"battery_channel", 7}
     };
     brainflow_boards_json["boards"]["50"]["default"] =
     {

src/board_controller/emotibit/emotibit.cpp

@@ -345,27 +345,35 @@ void Emotibit::read_thread ()
                     }
                 }
                 // ancillary package
-                if ((type_tag == TEMPERATURE_1) || (type_tag == THERMOPILE))
+                if ((type_tag == TEMPERATURE_1) || (type_tag == THERMOPILE) ||
+                    (type_tag == BATTERY_VOLTAGE) || (type_tag == BATTERY_PERCENT))
                 {
-                    int temperature_channel = 0;
+                    int channel_index = 0;
                     if (type_tag == TEMPERATURE_1)
                     {
-                        temperature_channel = board_descr["ancillary"]["temperature_channels"][0];
+                        channel_index = board_descr["ancillary"]["temperature_channels"][0];
                     }
                     if (type_tag == THERMOPILE)
                     {
-                        temperature_channel = board_descr["ancillary"]["other_channels"][0];
+                        channel_index = board_descr["ancillary"]["other_channels"][0];
                     }
-                    // upsample temperature data 2x to match eda
+                    if (type_tag == BATTERY_VOLTAGE)
+                    {
+                        channel_index = board_descr["ancillary"]["other_channels"][1];
+                    }
+                    if (type_tag == BATTERY_PERCENT)
+                    {
+                        channel_index = board_descr["ancillary"]["battery_channel"];
+                    }
+                    // upsample lower-rate ancillary values 2x to better align with EDA samples
                     if (payload.size () < max_datapoints_in_package / 2)
                     {
                         for (int i = 0; i < (int)payload.size (); i++)
                         {
                             try
                             {
-                                anc_packages[i * 2][temperature_channel] = std::stod (payload[i]);
-                                anc_packages[i + 1][temperature_channel] =
-                                    anc_packages[i][temperature_channel];
+                                anc_packages[i * 2][channel_index] = std::stod (payload[i]);
+                                anc_packages[i + 1][channel_index] = anc_packages[i][channel_index];
                             }
                             catch (...)
                             {
@@ -382,7 +390,7 @@ void Emotibit::read_thread ()
                         {
                             try
                             {
-                                anc_packages[i][temperature_channel] = std::stod (payload[i]);
+                                anc_packages[i][channel_index] = std::stod (payload[i]);
                             }
                             catch (...)
                             {