Test stability: uptime clock

lib/charts/UptimeClock.cpp

@@ -0,0 +1,28 @@
+#include "charts.h"
+
+void UptimeClock::draw(uint64_t t)
+{
+    t1 = t;
+    draw();
+}
+
+void UptimeClock::draw()
+{
+    uint64_t uptime = t1 - t0;
+    int mils = uptime % 1000;
+    int seconds = (uptime / 1000) % 60;
+    int minutes = (uptime / 60000) % 60;
+    int hours = uptime / 3600000;
+    String s = String(hours) + (minutes < 10 ? ":0" : ":") + String(minutes) +
+               (seconds < 10 ? ":0" : ":") + String(seconds) +
+               (mils < 10    ? ".00"
+                : mils < 100 ? ".0"
+                             : ".") +
+               String(mils);
+    int w = display.getStringWidth(s);
+    display.setColor(BLACK);
+    display.fillRect((display.width() - w) / 2, display.height() / 2 - 3, w, 7);
+    display.setColor(WHITE);
+    display.setTextAlignment(TEXT_ALIGN_CENTER_BOTH);
+    display.drawString(display.width() / 2, display.height() / 2, s);
+}

lib/charts/charts.h

@@ -153,4 +153,14 @@ struct WaterfallChart : Chart
     int x2pos(float x);
 };
 
+struct UptimeClock : Chart
+{
+    uint64_t t0;
+    uint64_t t1;
+    UptimeClock(OLEDDisplay &d, uint64_t t0) : Chart(d, 0, 0, 0, 0), t0(t0), t1(t0) {};
+
+    void draw(uint64_t t);
+    virtual void draw() override;
+};
+
 #endif