Implement light flashing for low battery alert / disabled debugging by default

src/src.ino

@@ -15,10 +15,10 @@
 // Various defines / pins / etc
 //  TWEAK THESE ACCORDINGLY
 // //////////
-#define DEBUG true
+#define DEBUG false
 #define INTERACTIVE_DEBUG false
-#define USE_SLEEP false
+#define USE_SLEEP true
-#define SLEEP_INTERVAL 1000 // miliseconds
+#define SLEEP_INTERVAL 500 // miliseconds
 #define ALERT_LEVEL 15 // battery alert level (%) [1-32% are valid values here]
 #define POT_BRIGHT A0
 #define POT_COLOR A1
@@ -32,7 +32,7 @@
 // Objects / values / etc
 // //////////
 MAX1704 fuelGauge;
-Metro timer = Metro(1000); // Timer for battery level alert (flashes pixels red or yellow [if red set]) to alert
+Metro timer = Metro(2000); // Timer for battery level alert (flashes pixels red or yellow [if red set]) to alert
 float charge_percent;
 uint8_t brightness;
 uint16_t raw_color;
@@ -54,6 +54,7 @@ void print_debug(); // Print debugging info if debug if debugging output is enab
 void read_values(); // Read values from various sensors/devices
 void do_low_power(); // Enable sleep / low power mode(s) as appropriate
 void pixel_update(); // Update pixel colors, on/off state, etc as appropriate
+bool show_low_battery_alert(); // Whether or not the low battery alert is to be shown
 ISR(WDT_vect) { Sleepy::watchdogEvent(); } // Setup the watchdog -- For sleepy
 
 // //////////
@@ -141,6 +142,10 @@ void read_values() {
 // Update pixels appropriately (on/off, color, etc)
 // ///////////
 void pixel_update() {
+  // Store temp variable for alert showing so it doesn't change mid-run
+  //   Metro timer is checked and is a method call that can/will change during this code block / method
+  bool pix_show_alert = show_low_battery_alert();
+
   // Set RGB array to values as appropriate
   if (white) {
     rgb[0] = rgb[1] = rgb[2] = 255;
@@ -150,20 +155,21 @@ void pixel_update() {
     color = map(raw_color, 0, 1024, 0, 360);
     hsvToRgb(color, 1, 1); // set rgb byte array
   }
+  
+  // Set to red/yellow for alert if alerting and the timer has run out
+  if (pix_show_alert) {
+    if (color <= red_threshold && !white) {
+      rgb[0] = 0;
+      rgb[1] = rgb[2] = 255;
+    }
+    else {
+      rgb[0] = 255;
+      rgb[1] = rgb[2] = 0;
+    }
+  }
 
   // Set color accordingly
   for (uint8_t i=0; i<NEO_PIX_NUM; i++) {
-    // Set to red/yellow for alert if alerting and the timer has run out
-    if (fuelGauge.isAlerting() && timer.check() == 1) {
-      if (color <= red_threshold) {
-        rgb[0] = 0;
-        rgb[1] = rgb[2] = 255;
-      }
-      else {
-        rgb[0] = 255;
-        rgb[1] = rgb[2] = 0;
-      }
-    }
     neopix.setPixelColor(i, neopix.Color(rgb[0], rgb[1], rgb[2]));
   }
   
@@ -175,6 +181,11 @@ void pixel_update() {
   
   // Apply changes
   neopix.show();
+  
+  // Introduce brief delay so there is a visible flicker when alerting
+  if (pix_show_alert) {
+    delay(500);
+  }
 }
 
 // //////////
@@ -202,6 +213,13 @@ void do_low_power() {
   }
 }
 
+// //////////
+// Figure out if the low battery alert needs to be shown
+// //////////
+bool show_low_battery_alert() {
+  return fuelGauge.isAlerting() && timer.check() == 1;
+}
+
 // //////////
 // Print debugging info
 // //////////