build for esp32 mask project

src/platform/arduino/BluetoothSerialTelemetry.h

@@ -0,0 +1,41 @@
+#include <Figments.h>
+#include <BluetoothSerial.h>
+#include <Ringbuf.h>
+
+class BluetoothSerialTelemetry : public InputSource {
+  public:
+    BluetoothSerialTelemetry();
+    void onStart() override;
+    InputEvent read() override;
+
+    template<typename T, uint8_t Size = 8>
+    struct Averager {
+        std::array<T, Size> buf;
+        unsigned int idx = 0;
+        unsigned int count = 0;
+
+        void add(const T &value) {
+            buf[idx] = value;
+            idx = (idx + 1) % Size;
+            if (count < Size) {
+                count += 1;
+            }
+        }
+
+        T value() const {
+            if (count == 0) {
+                return T{};
+            }
+            long long int sum = 0;
+            for(unsigned int i = 0; i < count; i++) {
+                sum += buf[i];
+            }
+            return sum / count;
+        }
+    };
+  private:
+    BluetoothSerial m_serial;
+    Ringbuf<char, 32> m_ringbuf;
+    CRGB m_color;
+    Averager<int16_t, 32> m_value;
+};