Infinity-loop.md

+## Measuring CO₂
+
+```
+static uint32_t timer0 = 0;
+TIMER(timer0, 5000)
+{
+    globalVars.ppm = co2.getPPM();
+}
+```
+
+Reads PPM and writes it into the global memory. `ppm` can't be more than 2¹³ - 1, I don't think it's possible under normal conditions.
+
+## Update time from RTC
+
+```
+static uint32_t timer1 = 0;
+static DateTime DTtmp;
+TIMER(timer1, 999)
+{
+    DTtmp = rtc.getTime();
+    globalVars.hours = DTtmp.hour;
+    globalVars.minutes = DTtmp.minute;
+    if(globalVars.seconds != DTtmp.second)
+        timer1 = millis();
+    globalVars.seconds = DTtmp.second;
+}
+```
+
+Every last millisecond it continuously updates time every cycle pass until `seconds` variable changes.
+
+## Swipe panel poll
+
+```
+static uint32_t timer2 = 0;
+TIMER(timer2, 10)
+{
+    buttons();
+}
+```
+
+This timer call _if spaghetti_ function. I'll be glad if someone will help me with tidying it. Function detects the event and writes it to the global variables. Screens have to null every event's boolean after reading (or rendering to ignore input).
+
+## Render
+
+```
+switch(globalVars.prepare)
+{
+    case 1:
+        screens[globalVars.currentScreen].funcPrepare();
+    case 2:
+        animate(50);
+    break;
+    case 0:
+        screens[globalVars.currentScreen].func(&screens[globalVars.currentScreen].arg);
+    break;
+}
+matrix.show();
+```
+
+Calls current screen's function and updates display. Calls `animate` in the transition. Currently there are no enough memory to store two matrix buffers, so `animate` function just nulls `prepare`.
+
+## `millis()` reset
+
+```
+TIMER(0, 3456000000)
+{
+    noInterrupts();
+        timer0_millis = 0;
+        timer0_overflow_count = 0;
+    interrupts();
+    globalVars.timer = 0;
+    tb.resetTimers();
+    timer_debug0 = 0;
+    timer0 = 0;
+    timer1 = 0;
+    timer2 = 0;
+}
+```
+
+Classical timer realization implies that millis() always greater than last memorized time. But system `timer0_millis` is not infinite, it nulls after UINT32_MAX, which means it will work **1 month 19 days 17 hours 2 minutes 47 seconds 295 milliseconds**. This timer resets all timers every month.
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