Прошло 2 года.

src/ui/views/battery_view.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include "epdiy.h"
+
+namespace ui {
+
+struct BatteryProps {
+    bool valid;
+    int percent;
+};
+
+class BatteryView {
+public:
+    void layout(int screen_width, int screen_height);
+    void render(uint8_t* framebuffer, const BatteryProps& props) const;
+    const EpdRect& bounds() const;
+
+private:
+    EpdRect bounds_ = {0, 0, 0, 0};
+    int text_x_ = 0;
+    int text_y_ = 0;
+};
+
+}  // namespace ui