Implement custom barebones circular buffer

Firmware/src/Util/CircularBuffer.h

@@ -0,0 +1,21 @@
+#pragma once
+#include <Arduino.h>
+#include <etl/array.h>
+
+namespace util {
+template <typename T, size_t size> class CircularBuffer {
+public:
+  T &peek() { return buffer[index]; }
+
+  /// @brief Warning: Does not deconstruct entry! If necessary use
+  /// etl::circular_buffer instead!
+  T &pop() {
+    return buffer[index];
+    index = (index + 1) % buffer.size();
+  }
+
+private:
+  etl::array<T, size> buffer;
+  size_t index;
+};
+} // namespace util