       }
     }
   } else {
-    radio.sleep();
+    radio.sleep(); // very important, reduces idle current draw from 16 mA to 0.2~0.3 mA
 
+#ifdef DEBUG
     Serial.flush();
-    for (int i = 0; i < 2; ++i) {
+#endif
+
+    for (int i = 0; i < 8; ++i) {
       LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
     }
 


  char msg[1] = {REQUEST};
  bool ack = radio.sendWithRetry(GATEWAY_ID, msg, 1);

  if (!ack) {
    DEBUG_PRINT("REQUEST failed\n");

#include <RFM69_ATC.h>
#include "LowPower.h"

//#define DEBUG
#include "DebugUtils.h"

// Device
